357 Sig Safety & Reloading FAQ

Disclaimer: The following information is what works for me. I am not responsible for your actions. Always refer to factory firearms instructions and precautions, refer to official reloading manuals when reloading, and especially be aware of Local, State, and Federal Firearms Laws. Use your common sense. You are responsible for your own actions!

Safety Precautions

Background

The 357 Sig is the first bottlenecked cartridge to hit the U.S. mainstream in almost a century. It has a short neck that holds the bullet in place. This neck is definitely sufficient to do the job as long as the cartridge is loaded correctly!

The 357 Sig was created in 1994. It's a mere babe in arms compared to the century old 9mm and .45. As a historical reference, the ever-popular .40 had some initial growing pains with guns and ammo when it was first introduced in 1990. It's a simple fact of life that it takes time for new pistols and ammo to mature, period.

The 357 Sig has matured nicely and now has several pistol models chambered for it, along with quite a few brands of ammo. Bulk 357 Sig reloading is now almost as inexpensive as 9mm reloading. The 357 Sig has a 9mm pistol size advantage of being able to push 124 grain bullets from a subsonic 995 fps up to a supersonic 1450 fps with a 4" barrel.

Good Factory Ammo

Some ammo companies now use a sealant/glue to hold the bullet securely in place. Reloaders have a few tricks up their sleeves as well, as you will see below. Some people make fun of the 357 SIG caliber because of this process. Actually, all duty calibers such as the 9mm, .40, and .45 can easily suffer from bullet setback as well, as you will see below.

Why go through the trouble of the sealant/glue? Ammo companies realize that agencies and those who carry concealed will load the duty ammo into their magazine and on occasion unload it so they can fire practice ammo. And after cleaning their pistol, the same duty ammo will be loaded into the magazine again and again. This duty ammo load/unload cycle continues, possibly for many months. The sealant/glue will help stop bullet setback, which occurs when the bullet slowly creeps farther into the case or suddenly just collapses into the case causing a catastrophic over-pressure event that may result in a case failure and/or the pistol blowing up. You have probably noticed that some ammo has a crimp ring on the brass to help hold the bullet in place.

I have a concern that pistol ammo is so price competitive that the quality control is sometimes hampered by not using adequate components and by hurrying products to market without testing each lot sufficiently.

Tips On Loading Duty Cartridges into A Magazine & Inspecting New Ammo

For those that carry loaded 357 Sig pistols on a regular basis and/or buy factory ammo occasionally, and you have to reload the same factory ammo into your pistol over and over again, here are a few easy checks. Actually, these checks should be performed no matter what semi auto pistol caliber you're using. This will become clear as you keep reading.

1.     When you reload your duty ammo back into the magazine, rotate the rounds so the previous cartridge that was in the chamber is now at the bottom of the magazine.

2.     Before loading your duty ammo back into the magazine, use a caliper to measure the OAL (over-all cartridge length) to make sure it is still within specs. Or, you may be able to just eyeball the ammo by comparing the rounds with an original unused round.

3.     If your gun can handle it, then ease the slide forward, so that the round is very gently pushed into the chamber. Then give the rear of the slide a rap, to be sure everything is locked up. This method is used by some Glockers I know and it definitely cuts way down on bullet setback issues, but you don’t want to cause a jam by not having the pistol in full battery.

4.     Whenever you get a new box of factory ammo, at the very least do a quick visual inspection. For 357 Sig ammo, it's a good idea to spot check a few rounds with the **thumb pressure test or by cycling a round through the gun a few times (being very careful of course). Measure the OAL with a caliper before and after these tests to make sure you do not have a defective lot of ammo. The bullet has to be secure enough so it can take the pressure of hitting the feed ramp to be chambered. Note: Brand new brass will hold the bullet in a superior fashion than reused brass.

5.     If you do have some bullet slippage from testing your duty ammo, then find out from your range officer or from the ammo company what the minimum safe OAL is before the cartridge must be destroyed. The minimum OAL may vary between brands because of powder burn rates, etc.

** The thumb pressure test technique: Put the bullet end of the cartridge on a hard surface, and then press down on the primer end with your thumb, being careful while pressing. You can use a bathroom weighing scale to press the bullet against. It should be able to take approximately 40 pounds of pressure.

Many calibers can succumb to the thumb pressure test and cycling test pretty easily. This is NOT just a 357 Sig issue. But a 357 Sig reloader does need to be cautious because of the short neck.

Example: I remember some time ago when I had a feed jam with my .45 caliber Glock 21. I examined the cartridge after I ejected it. I was surprised to see a bullet setback issue with part of the nose in the case. And I had made a strong crimp. I was so glad I had not fired it. Can you say, "Kaboom"! This is one example of why I do not fire a cartridge that has jammed on me until I double-check the OAL, etc, to make sure it is safe to reuse. Just tap, rack the slide and keep shooting.

I pulled the following picture from the XD/HS2000 talk forum, http://www.hs2000talk.com  which shows three stages of bullet setback with factory UMC 180 grain .40 ammo. The cartridge on the right was cycled through the slide and ejected several times. The middle cartridge was cycled less times, but after another dozen or so cycles, it looked about the same as the right most cartridge. The left cartridge has not been cycled at all. Like I said, it ain’t just 357 Sig ammo you have to worry about. This can and does happen to any of the duty calibers. I’ve seen and heard many times over the years how the 9, .40, and .45 have suffered from bullet setback, especially annoying if using expensive high quality factory defense ammo. Folks, be careful.

When I reload 9mm ammo, the bullet does not hold any better than when I reload 357 SIG ammo, regardless of the 357’s shorter neck. In fact, when I performed the thumb pressure test on a weighing scale, both the 9mm and 357 SIG reloads had similar bullet holding capability, which was good by the way. I was actually a little surprised that the 9mm did not get a better “thumb scale rating” than my 357 SIG ammo, all components being equal. I will add that reloading a little bottleneck case like the 357 SIG takes expertise in matching the reloading die setup to the bullet and case type correctly. But really, this is the same for straight wall reloaders, who may be suffering from bullet setback a lot more than they realize. Ammo companies that pump out bulk pistol ammo really need to keep improving their quality standards, especially with the 357 SIG. Like I said, ALL calibers have to be monitored for bullet slippage.

Ernest, an Ammo Manufacturing Engineer, made the following general statement:

"There are a TON of folks out there who constantly load and unload the top round in their magazine, and then complain that the overall length is changing. In fact, battery of the case neck can weaken it so much, that the shrinking tendency will rebound, and all of a sudden, the bullet is gone! Where? Down the bore! The darn things pop out of the case upon chambering and fly down the bore to create an obstruction for the next round. (This happens when there is excessive free-bore between the chamber mouth and beginning of the rifling) Then, the shooter complains I sent him a cartridge with no bullet. Never mind the fact the powder arrived in a case, without a bullet, and found its way into the chamber without spilling somewhere along the way." This is a case of extreme reverse bullet setback. Minor reverse bullet setback can be caused from ammunition that has a compressed powder charge. Weather conditions and/or each time the compressed round is chambered can possibly cause the bullet to creep out of the case a little. Obviously, this condition should be monitored to make sure the ammo is stable.

Since 1994 when the 357 Sig was created, ammo companies and reloaders have learned a lot. Ammo companies have learned to use a glue/sealant, brass crimps, proper bullet & brass mixes with proper crimping, etc. And I hope factories are checking each ammo lot sufficiently before releasing it to customers.  I have learned to bell the case mouth little if at all so the neck will have enough tension to hold the bullet in place. I have learned that the cartridge length, the case mouth, AND the shoulder are all important. I have learned that a cannelure groove and strong crimp work very well on the soft copper plated bullets, such as the Rainier 124 grain flat point, the West Coast 124 grain flat point, and the Speer 125 grain Gold Dot, to name a few. I have learned that a strong crimp on an Oregon Trail hard lead 122 grain bullet works well. I have learned that with hard-jacketed bullets, it's absolutely critical to bell the case mouth little if at all, and use a light crimp so the case is not damaged/wrinkled. A hard-jacketed bullet can even slip into the case if crimped too much. I have learned that a slow powder such as AA#9 can actually help hold the bullet in place. And I’ve learned that bullets with a diameter between .3555 and .356 work the best.

Summary: Important Ammo Safety Checks

1.     Once again, at the very least visually check your new ammo regardless of caliber. Open the factory ammo box to see if there are any cartridges lower or higher in the case than the others. And make sure the bullets, cases, and primers are not deformed. Checking a powder charge is difficult unless you pull the bullet and make a charge weight comparison. And even then, the manufacturer might have changed powders between one ammo lot and another.

2.     Once again, if your gun can handle it, then ease the slide forward, so that the round is very gently pushed into the chamber. Then give the rear of the slide a rap, to be sure everything is locked up. As mentioned above, this method is used by some Glockers I know and it definitely cuts way down on bullet setback issues.

3.     Once again, I recommend doing the thumb pressure test on a few rounds as a given. Or, cycle a few rounds through your pistol using the full force of the slide slamming into full battery. Do this in a safe area and be careful so you don't have an accident. Measure the before and after over-all length (OAL) of the cartridge with a caliper. This testing will reveal if your ammo has a major bullet slippage problem or not. You should not use the thumb pressure test on some ammo, such as soft tip RBCD ammo, otherwise the bullet tip will be flattened. In this case, you should use the alternate slide cycle test.

And no, this does NOT mean that if you are in an emergency and have to load a magazine or use new ammo, that you must first visually inspect each round and do thumb pressure checks! Come on folks! Be prepared before you start carrying your pistol!

4.     And remember Ernest's statement above about continually re-chambering the same round which can cause extreme reverse bullet setback, regardless of the semiauto caliber. Also, remember to monitor compressed loads to make sure minor reverse bullet setback stays within acceptable limits.

5.     Don't assume factory ammo is somehow infallible. Following some simple safety checks as mentioned here is useful for all calibers. There is bad factory ammo that accidentally hits the streets on occasion! While new 357 Sig factory ammo has improved, there may still be some older ammo that's been sitting on the shelves for years. Better safe than sorry.

Important Loading Safeguards to Compensate for the short 357 Sig Neck

1.     Use a soft copper plated bullet with a firm crimp (aprox. 0.378). You can use a light cannelure groove for the ultimate in bullet setback safety.

2.     Glue/sealant is used by some ammo companies.

3.     If possible, a crimp ring on the brass may very well help hold the bullet in place.

4.     Belling the case mouth little if at all is necessary so there is enough tension to hold the bullet.

5.     If you use hard-jacketed bullets, you need a lighter crimp, otherwise the bullet can easily slip into the case and/or the case can even get wrinkled/damaged.

6.     Using one of the slowest pistol powders, AA #9, can work as a compressed powder to prevent the bullet from slipping into the case too far. Read my AA No.9 article at my site for more details (pointer at bottom).

7.     For quite awhile, I have believed the bullet diameter range for the .357 SIG to be .355 to .356. You can get a 9mm .355 bullet to work in a 357 SIG case if it is shaped correctly and the correct bullet crimp is used for the type of bullet being used. After doing my own limited testing, I now believe the 357 SIG ideally should use a bullet diameter between .3555 to .3560, and not the standard size .355 bullet, if possible. The correct bullet size and shape is a critical step to minimizing bullet setback. A main reason why West Coast Bullets work excellently in the 357 SIG caliber is because they happen to measure .3555. The SAAMI maximum for the 357 SIG bullet diameter is .3555.

8.     Follow the general reloading rules as stated below in the section entitled "Some Reloading Details".

Two Styles of 357 Sig Reloading

Due to the nature of the 357 Sig cartridge, I have used two different die set configuration styles depending on the bullet type I use. The first die set configuration is adjusted for using soft copper plated bullets such as the Rainier 124 grain flat points, West Coast 124 grain flat points, Speer 125 grain Gold Dot HP's, and even Oregon Trail hard lead 122 grain flat points, etc. The second die set configuration is adjusted for using hard-jacketed bullets such as the D&J 124 grain flat points, etc.

Die Set Style 1

Tools: Dillon 550 Press & Dillon Die Set with the exception of an RCBS Roll Crimp Die or Lee Taper/Roll Crimp Die.

For the die setup using soft copper plated bullets, I first apply a light cannelure groove on the bullet (optional, but it gives the best bullet setback security). I then apply a strong crimp during the reloading process. I use little or no belling of the case mouth to help hold the bullet in place. When the RCBS crimp die is being used, it is only about 4/1000" from touching the Dillon shell plate (about the thickness of a piece of bond paper).

And yes, it is possible to just make a strong crimp on a soft copper plated bullet without using a cannelure groove, although it cannot match the security of the cannelure groove/strong crimp duo. See crimp tests below for more details.

For Oregon Trail hard lead 122 grain flat points, I apply a strong crimp that cuts a crimp ring into the bullet, without using a cannelure groove.

Die Set Style 2

Tools: Dillon 550 Press & Dillon Die Set.

For the die setup using hard-jacketed bullets, little or no case mouth belling is a must so the neck has plenty of tension to hold the bullet in place. I use little or no taper crimp, otherwise the bullet can get loose and slip into the case easily, and it can actually damage/wrinkle the case. After the bullet seating stage, the case mouth diameter generally measures around .379, which is actually less than the .381 SAAMI standard. So little or no crimp is necessary.

Four Different Crimp Tests

Let's take a look at 4 different crimp tests, which shows how strong each bullet crimp style is. Note: each style used little or no case mouth belling in order to grab the bullet as tightly as possible.

1.     Strong crimp using soft plated bullet -- with a light cannelure groove.

2.     Strong crimp using soft plated bullet -- no cannelure groove.

3.     Light crimp using a hard jacketed bullet.

4.     Strong crimp using a hard jacketed bullet.

Crimp Test 1 (Cannelure Groove & Strong Crimp)

The main purpose of this test was to test a cannelure groove and strong crimp using a soft copper plated bullet to see how well this method works.

A Hornady once fired brass was used because I've found that bullets can slip the easiest with this brand. I have nothing against Hornady. I can tighten the crimp slightly to compensate for the difference between Starline and Hornady brass.

I used a Corbin Cannelure tool to apply a light groove on the Rainier bullet. This is a very easy and fast process.

I then loaded one dummy round with no powder or primer. The original OAL began at 1.1165.

I performed the thumb pressure test (55 lbs as measured on a bathroom weighing scale). OAL became 1.116. Generally, 40 lbs is considered good enough to simulate the bullet hitting the feed ramp in a pistol. The miniscule 5/10,000" slip might have actually been caused from putting pressure on the soft plated bullet nose itself.

I cycled the dummy round 10 times (full force) through my pistol. OAL became 1.1155.

I then did another thumb pressure test two times (55 lbs). OAL became 1.114. So far, after 13 forceful tests, the bullet has slipped .0025. Note: If I had used my normal Starline brass, slippage would be even less. Using Hornady brass is my worse case scenario.

I then did one more thumb pressure test at 90 lbs (more than double the necessary pressure)! OAL became 1.108. The Rainier bullet nose was still above the case mouth and the bullet could be crimped correctly if desired. If I had loaded a mild 12.2 grains of AA No 9 powder, the bullet would now be fully supported by the powder and not be able to slip anymore. A higher powder charge would have kept the OAL longer of course. Refer to my AA #9 powder article regarding its use as a form of bullet setback security.

Lastly, I went to the garage. I grabbed my Dillon flat wrench to help support my thumb pressure. I forcefully did a thumb pressure test against the cement floor, literally banging the bullet as it hit the cement. I did this four times before the bullet succumbed and plummeted into the case. The last four extreme tests, brought the total to 18 tests. The only normal tests in this series, was the cycling of the dummy round through the pistol ten times. All the other tests were greater than would be expected during a normal cartridge feeding cycle in a pistol, except for possibly a feed jam of some kind.

Crimp Test 1 Summary

Well, I really had a sore thumb for awhile.

The cannelure groove on a soft copper plated bullet in conjunction with a strong crimp really works very well! If you don't want the straight walled pistol reloaders scoffing at you, this method works great and you have nothing to be embarrassed about. Just tell 'em it's like reloading a little rifle cartridge.

This method would be best for those that might re-chamber the same ammo many times, or for those that just want the maximum insurance against bullet setback.

Note: Even though Rainier bullet plating is thinner than West Coast plated bullets, it still works well with a light cannelure groove.

Crimp Test 2 (Strong Crimp -- No Cannelure Groove)

This test is for those that may not want to put a cannelure groove on their bullets J Instead I just used a strong crimp on a soft copper plated bullet. I tried to follow the same test procedure as above.

I used the Hornady once fired brass again.

I then loaded one dummy round with no powder or primer. The original OAL began at 1.116.

I performed the thumb pressure test (55 lbs as measured on a bathroom weighing scale). OAL became 1.1145. Once again, 40 lbs is considered good enough to simulate the bullet hitting the feed ramp in a pistol.

I cycled the dummy round 10 times (full force) through my pistol. OAL became 1.119. Whoops. Does something look strange here? That's right! The force of the slide closing actually caused a reverse bullet setback -- the bullet slipped out of the case by 0.0045", although the bullet was still held securely. As I held the cartridge, I could fairly easily push the bullet back into place with my thumb. The OAL then rested solid at 1.1145 again.

I then did another thumb pressure test two times (55 lbs). OAL became 1.114. This time, after 13 forceful tests, the bullet has slipped .002, although we had some reverse bullet setback occur during the slide racking test. At times, I've had a little reverse bullet setback when using a cannelure groove as well, although it is usually 0.001 to 0.002. The bullet continues to hold well when this occurs unless it occurs to the extreme of course, which I have never experienced. Remember the quote mentioned above when Ernest, an Ammo Manufacturing Engineer, talked about this same phenomenon with factory ammo of various semiauto calibers.

I then did one more thumb pressure test to see if I could reach 90 lbs, which is more than twice the 40 lb standard. Nope. The bullet totally collapsed at 60 lbs, which is still well over the 40 lb standard.

Obviously I did not make it to the garage to do the last severe thumb pressure test by beating the bullet on a cement floor as I did in test 1.

Crimp Test 2 Summary

Using a strong crimp without a cannelure groove proved to hold up pretty well. I was not surprised that it did not hold up as well as the cannelure groove and strong crimp combination.

For those who will most likely just chamber a round once or twice, this method might be just fine. It's your choice.

Crimp Test 3 (Hard jacketed bullet with a light crimp)

I performed test 3 with the excellent D&J hard jacketed 124 grain bullet. I could not do the same test procedure as above because hard bullets just do not hold up as well, at least for me.

OAL start length of 1.1345 and a "light" crimp, using a once fired Hornady brass:

Racking the slide test:
3 racks: OAL: 1.1335
4 racks: OAL: 1.133
7 racks: OAL: 1.132
8 racks: OAL: 1.131
10 racks : OAL: 1.129
11 racks : OAL: 1.1275
12 racks : OAL: 1.127

Then I did one thumb pressure test. At 40 lbs (using a bathroom weighing scale) the bullet completely collapsed into the case.

Crimp Test 3 Summary

As expected from my previous experience, a hard jacketed bullet cannot hold up to a torture test like a soft copper plated bullet -- no contest.

With a light crimp, a hard bullet seems to do fine for a few slide racks. If one just plans on the ammo hitting the feed ramp once or twice, then this method might be OK. You just have to be really careful about the bullet choice and that it is holding securely in the neck. There's not much room for error when using hard jacketed bullets. All I can say is AA#9 powder looks really good when using hard jacketed bullets because of its bullet setback insurance.

Crimp Test 4 (Hard jacketed bullet with a strong crimp)

I then created one more dummy cartridge and made a "strong" crimp this time.

Start OAL: 1.130
One slide rack: OAL: 1.1215
2nd slide rack: bullet collapsed into the case

Crimp Test 4 Summary

Don't do it.

With a heavy crimp, the hard jacketed bullet slipped badly right away, as expected from previous testing I've done. The method of using a hard jacketed bullet with a strong crimp is unsuitable and quite dangerous, period.

The Crimp Summary Ratings

Cannelure groove on soft plated bullet and strong crimp:

          Rating: Excellent

Soft plated bullet and strong crimp -- no cannelure groove:

          Rating: Good

Little or no case mouth belling and a light crimp using a compatible hard jacketed bullet:

          Rating: OK  

Little or no case mouth belling and a strong crimp using a compatible hard jacketed bullet

          Rating: Bad (failed)

Some Reloading Details

A reloading advantage of the 357 Sig over the .40 is that you can buy plated and jacketed 9mm bullets for $30 to $50 per thousand, depending on who you buy from and whether you buy in bulk or not. This is an excellent price, especially when comparing it to plated/jacketed .40 S&W & .45 ACP bullets. Besides the fine quality Starline 357 Sig brass, you can now get once fired 357 Sig brass from Midway, and from Ken's Ammo & Reloading in Manchester, NH (603-622-1680), just to name a couple places.

Here's some basic reloading rules that I've picked up over time:

1.     I'd recommend cleaning your brass before checking it. Not only will you not have to worry about scratching your resizer die, you will be able to see defects much easier. Using a Dillon or Midway brass polish (or whatever brand you like) also puts a protective coating on the brass as it is vibrator tumble cleaned. Make sure you do not have any of this liquid polish stuck inside the case with some walnut/corn kernels stuck in it --- this can cause a squib load since the primer will not be able to ignite the powder --- this has happened to me twice. In other words, when you pour a little brass polish into the cleaning material, make sure it is thoroughly mixed before adding your brass!

2.     Check your brass each time before reusing it. Throw out anything that will not handle a full power load (thin brass, badly dented, creased, and anything that looks suspicious in any way).

3.     If your brass is clean and yet it is still getting scratched during reloading, then read on. A fellow reloading friend told me that he talked with folks at CH and a couple of guys over at Dillon. Their general consensus is DO NOT USE NICKEL PLATED BRASS!! Nickel particles (no matter how clean the brass) flakes off and serves as little cutting tools digging into the steel of the sizing die. And under pressure, these flakes are so imbedded into the steel as to be practically welded in! With a Carbide die set, you might "hone" out the carbide with some 600 grit abrasive paper on a wood dowel if it seems to be holding some flakes.

4.     Count your fired brass usage so everything in a given group has the same age, wear, brand, etc. I've found that different brands of used brass have different characteristics. So a bullet that fits snugly in one brand case may not quite be snug enough in another brand's case. This is due to differences in the gun that it was fired from and the differences in case length, case wall thickness, brass age, etc. If you use one brand, then you can adjust the dies to work adequately with that particular brand. It only takes one bad reloaded cartridge to ruin your day.

5.     Check the trim length, especially if you are loading full power rounds. If you use groups of brass as mentioned in item 3, you may be able to just spot-check a few brass to get a good idea if the trim length is staying within specs. If you don't use groups of brass, then you should check every brass. I've never had to trim my 357 Sig Starline brass.

6.     Lightly spray lube the cases before resizing. I use a light lube even though I use a Dillon Carbide die set. I also spray lube my straight walled cases because the Dillon press works much smoother and there is less fluctuation of the OAL. Note: The Dillon Spray has an alcohol base. When you first spray, the brass feels wet. Within a few minutes, it feels almost sticky dry as the alcohol dries after spreading the lube around the cases. Do not over-spray since the cases can be damaged with dimples. Hint: lay all the brass on its sides before spraying so the lube can spread over the cases evenly. I've heard that some folks lube every fourth or fifth case only. I find it easier to just throw all the brass in a box and lightly spray all the brass at once.

7.     Do a full case resizing to form the brass as close as possible to its original shape. Especially make sure that the neck is long enough (compare with a new case; aprox 0.150) and that the shoulder is positioned correctly (see measurements below). I highly recommend the Dillon carbide resizer, which does an excellent job. It's expensive and costs around $75, but well worth it. The carbide resizer still requires lightly lubed cases, but does not produce as much friction as all-steel resizers, and makes operating the press a little bit easier. If you're tight on money, the $20 Lee 357 Sig die set works great and might actually resize the brass about 1/1000" smaller than the Dillon resizer. I crank my Dillon resizer all the way down firmly into the Dillon 550 shell plate -- this is the only way I can get the correct neck length. Your equipment may vary.

8.     Expand the case mouth little if at all so the bullet will just "barely" squeeze into the case. This will cause the bullet to hold much more firmly in place --- I cannot overstress this very important point! A bullet with a slightly beveled base, or even a tapered base, is best (example: Rainier or West Coast 124 gr. flat point copper bullets work very well, and you can buy these bullets in bulk; Rainier bullets are sold by http://www.Midwayusa.com and http://bluepress.com; West Coast bullets can be ordered directly at http://www.westcoastbullet.net ).

9.     Another possibility is to lightly chamfer the case mouth so a bullet can be seated without crushing the case. I have sometimes used this technique when inserting an unbeveled bullet into brand new Starline brass.

10. For compressed powder reloading information and the special techniques involved, please refer to my AA #9 powder article at my site (listed at bottom of this article). AA #9 appears to provide some bullet setback security, based on my limited experience.

11. Use a 9mm bullet that has a minimum .355" bearing surface at the point where you will be crimping, otherwise, the bullet will have a bullet setback problem. Many 9mm bullets are unsatisfactory because they have a long tapered bearing surface. Some are deceiving since they measure around .352 or so at the crimp point. Be careful. Actually, bullets measuring .3555 to .356 appear to be ideal.

12. Soft copper plated bullets that work well with a light cannelure groove and strong crimp are: West Coast 124 grain flat points, Rainer 124 grain flat points, and Speer 125 grain Gold Dot HP bullets. Oregon Trail 122 grain hard laser-cast flat points work well with a tight crimp that cuts a crimp groove into the bullet. You can find Oregon Trail at: http://www.laser-cast.com Note: Don't crimp too tight or you can wrinkle the brass or deform the bullet, but do it tight enough so it passes the thumb pressure test, as mentioned in detail earlier in this article.

13. Hard FMJ bullets only seem to work well with little or no crimp and little or no case mouth belling to help hold the bullet in place. This technique does not appear to hold the bullet in place as well as the cannelure/strong crimp technique described above with soft plated bullets. The Dillon crimp die works well with hard bullets.

14. A firm crimp with an RCBS roll crimp (Some people like the Lee roll/taper crimp) works best for the soft copper plated bullets. The diameter right at the actual case mouth edge might only measure around .370, while the middle of the neck measures .378. This is good. This may be shocking if you believe the 357 Sig must head space on the case mouth only. Actually, the case mouth and the shoulder are both important. And the 357 Sig should be treated like a little rifle cartridge.

15. Corbin makes a great cannelure tool called the HCT-1 for reloaders. Corbin also makes an industrial model called the PCM-1 that can create 6000 cannelures per hour. (Corbin: 541-826-5211; www.corbins.com) The cannelure groove should be applied lightly enough so it simply roughens up the bullet surface but does not cut deeply into the copper plating. CH also makes a cannelure tool: www.ch4d.com

16. Wipe the lube off of the assembled cartridges by using a vibrator tumbler for aprox. 12 minutes, or use whatever technique you feel comfortable with.

17. In general, I prefer to use the upper end of the maximum Over-All Length for the 357 Sig cartridge. Maximum is 1.140. So I generally keep my rounds around 1.135. I have seen some factory ammo as short as 1.122. Vihtavuori recommends an OAL of 1.122 with their N350 powder. A longer OAL is a good safety factor for lessening an over-pressure occurrence, just in case an unexpected bullet setback should occur. Just between you and me, I believe there is a lot more .40 caliber bullet slippage than many people realize.

18. You can look at the powder section of my web site to view various chronograph charts and test results. The Sierra Reloading Manual, the Speer Reloading manual, the Alliant Reloading Manual, the Accurate Arms Reloading Manual, and www.reloadammo.com give examples of several powders used for the 357 Sig. The newest editions of Reloading Manuals that will be coming out in the near future will no doubt be supporting this new round as well. Vihtavuori has 357 Sig reloading data available in their free reloading guide..

19. Pistol Cleaning Note: With the new .357 bottlenecked cartridge, you must be very careful to actually clean the INITIAL *wide part* of the chamber. One way to do it, is to use a .40 caliber or 9mm bore brush to clean ONLY the wide part of the chamber. Then, use the 9mm bore brush to clean the rest. Just don't get carried away and ram the .40 caliber brush all the way through the bore!

20. Double check a reloaded test sample before making a huge batch. Take the barrel out of your pistol and drop a factory round into the chamber to see how it fits. Then drop a reloaded round into the chamber to compare how it fits. If the round sits too high, then you are probably not resizing it quite right. You have to do a really full resize with this caliber to shape the brass and lengthen the neck correctly, as well as make sure the shoulder is positioned correctly. And make sure the case length is within specifications. Once the resizer die is positioned correctly, the correct brass shape should happen automatically from then on.

Headspace Issues

The very first 357 Sig article I read was in 1995, written by Ed Sanow. He got his facts from Federal and Sig Saur. At that time, he wrote that the 357 Sig headspaces on the case mouth, making it easier to measure the OAL (over-all length).

Well, the 357 Sig has been maturing. Now I've been told from a couple reliable sources, that the 357 Sig headspaces on the case mouth and the shoulder. More, recently, I read that the shoulder has precedence in determining headspace, but the length is still important.

Based on all of this interesting headspace info, I currently believe that if you are experiencing light primer strikes and inconsistent ignition, then very likely, cases have been sized with an improperly positioned shoulder. All the other measurements like trim length, OAL, etc, are important too of course.

I base this information on my own personal experience, and the important archive headspace article, www.realguns.com/archives/001.htm

At the very least, I hope most of us can agree that the case length and shoulder placement are both important.

The shoulder sets headspace when referring to the MAXIMUM length. Just as with other auto pistol rounds, the 357 Sig sets its MINIMUM headspace with the extractor. In other words, no matter how far back you set the shoulder or trim the case mouth, the case won't move forward any farther than the extractor will allow it to.

I even know of a local ammo company that still resizes .40S&W brass into 357 Sig cases, which means the cases are too short. Yet, these reformed cases shoot perfectly and have been a popular low priced 357 Sig ammo alternative. However, I would not recommend using reformed .40 brass for reloading purposes --- the internal structure of the .40 S&W case is too weak for multiple 357 Sig firings. In fact, be careful what brass you pick up at the range. Make sure it has a 357SIG head stamp on it!

Now, if the 357 Sig shoulder is out of place, the cartridge has severe problems.

Differences Between Loading New Brass and Used/Fired Brass

It's easy to load "new" 357 Sig ammo to headspace on the case mouth. But for remanufactured ammo and for reloads, it is a completely different ballpark. After firing 357 Sig ammo, the case neck tends to shorten and the shoulder has a slightly different look to it. After performing a full resize to a lightly lubed case, the case is lengthened again, the shoulder-to-base length should be approximately 0.6820, and the case neck should be lengthened to approximately .150.

Reloading the 357 Sig should work fine as long as the shoulder placement is correct and the maximum case length is less than 0.865 and greater than 0.850. Drop a reloaded cartridge into the barrel (removed from the pistol) to make sure it fits and chambers correctly.

I've reloaded the same 357 Sig brass for up to ten times, and all the brass measurements were still fine. I know some people have reloaded brass even more times. Just be careful and don't use brass that cannot handle the psi of a 357 Sig cartridge. In other words, do NOT use brass that is cracked, heavily dented, or is beginning to thin, or looks damaged in any way. And do NOT use brass that is not stamped 357 Sig. Be careful.

357 Sig Reloading Dies, Etc

I have been lucky with my particular 357 Sig setup. I have two die sets. One is a Dillon die set. The second one uses all Dillon dies except for the RCBS roll crimper and sometimes a Lee roll/taper crimper. There are many different dies, presses, bullets, guns, people, etc. So some people have had problems and others haven't. Hopefully, as we all learn more about the very young 357 Sig, and get "CORRECT" reloading data in official published form, it will be easy for a "New Reloader" to come up to speed fast. After all, the 357 Sig ain't a century old like the venerable 9mm and .45 --- nothing like being a pioneer! And you are a "hot reloader" if you can reload something other than a straight walled caliber. Once you get the facts and set up the die set, it's just as easy and fast to reload the 357 Sig caliber as a straight walled caliber. I mean, straight wall reloaders lube their brass too so it's easier to operate that awesome progressive press, right?

357 Sig Specifications

The base of the shoulder is 0.6490", measured from the bottom of the case. The top of the shoulder measures 0.7150". I was taught that a bottlenecked cartridge headspaces midway on the shoulder. In the case of the 357 Sig, that means it headspaces at right around 0.6820. With a caliper, it is easy enough to measure from the bottom of the case to the mid shoulder position to see if you're in the ball park.

Here's the SAMMI chamber allowances for the 357 Sig:

.4275 min .4315 max at the rear of the chamber

.4254 min .4294 max at .600 forward in the chamber (mid front)

.4250 min .4254 max at .6626 forward in the chamber (at the neck edge)

Max over-all-length (OAL): 1.140

Min over-all-length (OAL): 1.120 (based on reloading manuals and factory ammo)

My preferred over-all cartridge length (OAL) generally ranges around 1.135, although I sometimes use 1.122 with certain powders.

Mouth: .381

Neck length: aprox. .150

Nominal bullet diameter: .355 hard jacketed bullets, .3555 plated bullets, and .356 hard lead bullets

SAAMI Maximum bullet diameter: .3555

Ideal bullet size: .3555 to .356

40,000 psi --- maximum average pressure.

Small primer.

Max case length: .865

Trim-to length: .860

A Little Bit More Reloading Info

The following information is provided to simply give you some ideas about some available reloading information, as well as show a sampling of powder types that can be used for the 357 Sig. Under-charges can be just as dangerous as over-charges.

Non-exclusive list for 357 Sig reloading info:

Speer/Blount 208-746-2351

Accurate Arms Company 800-416-3006; (www.accuratearms.com)

Hodgdon (www.hodgdon.com)

Vihtavuori/Nammo Lapua Oy (www.vihtavuori.fi/vihtavuori/)

Alliant (www.alliantpowder.com )

Sierra 50th Edition Reloading Manual

Sample 357 Sig chronograph data can be viewed in the powder section of my web site. And visit www.reloadammo.com to view various powders that can be used.

Dillon Blue Press (800-223-4570) makes an excellent carbide die set for the 357 Sig; http://bluepress.com

Midway (800-243-3220) www.midwayusa.com

Several barrel companies support the 357 Sig caliber:

Jarvis 406-961-4392

Bar-Sto 760-367-2747; http://Barsto.com

Olympic Arms

KKM Barrels

Die sets I've used and like: Dillon (carbide die set), Lee taper/roll crimper, and RCBS roll crimper. The RCBS die on a Dillon 550 only leaves about 4/1000" of clearance and it crimps at a sharp angle into the bullet. The Lee crimp die has a more gradual but firm crimp and has more of a tendency to squeeze more surface area of the bullet ( too much Lee crimp can deform the bullet; you can test this by crimping and then pulling the bullet to see if the bullet diameter is the same or not).

Corbin makes an excellent cannelure tool. (541-826-5211; www.corbins.com )

Pro-Ears provides excellent electronic ear protection. Various companies like Dillon, Midway, etc also sell electronic ears. www.pro-ears.com

West Coast Bullets: www.westcoastbullet.net Nevada 800-482-2103 or 206-282-4451.

Oregon Trail Laser Cast Hard Lead Bullets (122 gr flat point BB); www.laser-cast.com; 800-811-0548

Don't resize 10mm brass or .40 S&W brass into 357 Sig brass. There is an abundant brass supply from Starline (800-280-6660; www.starlinebrass.com) and from ammo companies. The 10mm has different internal construction along with large primers; As a result, the combination could be quite dangerous.

Another good reason to use real 357 Sig brass is because the internal 357 Sig case dimensions are more beefed up than the .40 S&W case.

Addendum

I'm not trying to be a know-it-all by giving out this information. If anybody has more information, additions, and/or corrections, please let me know. I just want everyone to be safe while they're shooting the excellent 357 Sig round. And I strongly believe that anyone who uses the 357 Sig should be aware of the facts.

Here's some sites that have some good 357 Sig info:

www.realguns.com/archives/001.htm

www.greent.com

www.recguns.com

www.gunnery.net

www.sigarms.com