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Said waaaat.... 357Sig Glock blow-ups due to a heavy crimp?

6K views 64 replies 22 participants last post by  Taterhead 
#1 ·
Recently a guy on another websight suggested that a top load 357Sig reload can blow up a Glock if the crimp is applied too strong. All he offered for the comment was "Ask me how I know this." While I do know that the 357Sig is loaded to higher SAAMI pressures then many other of the usual auto pistol rounds, I have NEVER heard of ANY cartridge (rifle or pistol) blowing up a pistol solely due to over crimping the case. If a "blow-up" truly happened, I would presume the cause was more likely due to his reload going over the red line of the SAAMI limit to begin with.... and much less to do with an excess crimp on a round reloaded within SAAMI limits.

During 40 years, I personally have applied stout roll crimps onto all kinds of hot loaded handgun ammo including 44 mag and 10mm, and I find it hard to believe that a 357Sig is the exception. Anybody else heard of this with the 357Sig?
 
#37 ·
"and the factory Glock barrel does not fully encase the rim,"

If you look at many other pistols in .357sig and other calibers. You will find that .357sig Glock barrels made within the last 15 years or so actually have very good support in comparison.
 
#39 ·
I've had a G31 for several years and its case support is as close to full as I've ever seen in a Glock.
Or any 357sig for that matter.
 
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#40 ·
I sound like a broken record (come to think of that, some of our younger members probably don't even know what that means, ugh), but Glock makes their chambers so the round for which they are designed, feed reliably under adverse conditions. In straight walled calibers (380, 40, 45 Auto) they have fairly generous chambers to aid in worst case feed reliability (you know all the torture test stuff).

In calibers that don't need any help feed wise (9mm tapered case, 357 SIG bottle necked case), you will find Glock chambers and head support to be some of the best in the industry.

The Glock engineers take all this stuff seriously, they aren't just sitting around telling the production guys to hog those chambers out a little more... :). There is a reason for every single design element.
 
#42 ·
I sound like a broken record (come to think of that, some of our younger members probably don't even know what that means, ugh),
LOL..... yep, on that subject, many young uns out there also don't know what one of these things is. Of course, you and I who go way back recognized it to be one of the original air-soft targets intended to be suspended from a string. Didn't we have fun trying to get an air-soft pellet to stick in that center hole? ;) (wink)

Yellow Photograph White Font Grey
 
#43 ·
Well, bullet setback in any semi auto is what I have witnessed as the absolute cause of KBs. But powder used for a 357SIG will pretty much fill the case, and if doubled you will have more powder on the shell plate that in the case. If this guy crimped it so much that it shortened the OAL, with who knows what weight and shape bullet? yea, maybe..... But there is really no crimp on a 357SIG anyway. The problem with all these stories is the info is more than incomplete. I've loaded over 12,000 rounds using BE-86 between 6.8 and 8.4 grains, 1.130-1.155" OAL, with 124 grain MG JHPs, Bayou 124 grain flat points and and 151 grain Blue Bullet RN. Chrono's from 1,575 to 1,120 fps to make USPSA Limited Major. No issues. There really is no crimp on a 357SIG anyway..






OEM loads

 
#46 ·
I'm sure something else caused the problem, not crimp. I've loaded the 357 SIG to some wild levels using actual 357 Mag bullets (125gr, 140gr and 158gr) with no issues and they were very warm...zero issues.
 
#47 ·
Must have been the same guy I overheard at a local Turners who was talking about a guy he knew at the range who said his brother was a cop and knew this other guy who had a G31 that he got used from a friend in Arizona and shot some reloads he got at a garage sale and blew it up because they were over crimped.

Here is over crimped, question is how do you get them to chamber??? Well the guy in the story said they used a ball peen hammer to drive them into the barrel...

 
#48 ·
That's not overcrimped. That's the case mouth folded over. Case mouth benefits from a chamfer if you use flat bottom bullets. I've also seen the reverse happen (the case mouth folds outwards), if it get caught off center in a Dillon powder funnel. Case gauge might have caught this. Lee FCCD would not (they don't make one for 357 Sig!).
 
#49 ·
#51 ·
The ones in the picture were standard Dillon dies using once fired untrimmed brass. Nobody makes a 357SIG case gage, but the LE Wilson head space gage did reject those. However, when I switched to the Lee FCD, with no other changes, then no more problem.

Lee FCD at Midway, $21
http://ads.midwayusa.com/product/892254/lee-factory-crimp-die-357-sig?cm_mmc=pf_ci_google-_-Reloading+-+Dies+&+Shellholders-_-Lee-_-892254&gclid=CPDlqZHMsNICFUOXfgodew4Dqw

LE Wilson headspace gage
http://www.midwayusa.com/product/617282/le-wilson-case-length-headspace-gauge-357-sig

I also use the Lee FCD (not carbide) for 357Sig on my 550b, and no problems either. I have the same gauge, it works well.

The Lee FCD collet will "iron" those folds back; but it looks like it's being caused by the bullet snagging the case mouth. I had that problem till I chamfered a batch of case mouths. Became more of an issue since I don't put much (if any) flare on the cases (I'm using the 9mm funnel). Also not a problem if the bullet had a taper in the base.
 
#52 ·
Well, in my setup, it was not showing up after seating, but after crimp with a Dillon die. The bullets are Montana Gold 125 JHPs and the brass is once fired indoor Speer. Like I said, when I got the Lee FCD, and changed nothing else, no more problems in over 12,000 rounds, since the initial setup. I don't trim or chamfer, and instead of case lube, I use Miller Stephenson 122 PTFE dry mold release that doesn't have to be removed. Load is 7.8 grains of BE-86 for the 125s, and 7.2 grains for the 151s. Makes USPSA Major, but it's still stout.



 
#54 ·
I don't trim or chamfer, and instead of case lube, I use Miller Stephenson 122 PTFE dry mold release that doesn't have to be removed.
At first I was sizing the body with a carbide 40S&W, then finishing the neck with a 357Sig die. I clean all my brass with pins and use a wash/wax solution along with the Lemishine. I found that the cleaned 357Sig brass went though the 357Sig die with no additional lube.
 
#55 ·
I tumble in walnut loaded with a couple of teaspoons of mineral oil, overnight to clean, then in corn with a couple of teaspoons of NuFinish car polish, overnight to shine them up. They go thru pretty good, but the mold release makes it even easier. Just a couple of sprays on each hand full of cases, and like I said, no cleaning needed.

from nasty to happy

 
#56 ·
Try mixing 50/50 of the walnut and corn cob, and 50/50 mixture of mineral spirits and Nu-Finish car polish, also add steel BB’s to the mix blend in so as no lumps in the media, add the brass some cut up dryer sheets. The dry sheets help in keeping the media cleaner and last longer. And the BB’s help in cleaning the inside of the case’s also.
 
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#58 ·
Yes, then when you need to change out the media, use a magnet to remove the BB”s, then add those back in with the new media. You will be surprised in the difference those BB’s make.
 
#63 · (Edited)
Inexperienced reloaders who are having neck tension problems (common on the short necked .357 Sig) often try to compensate for this by dialing in some more crimp. What they don't understand is that because of the elasticity of the brass you cannot attain more neck tension without crushing the bullet. Proper neck tension is achieved by proper sizing and proper bullet selection.

I can almost guarantee that what happened is that the reloader in question was having neck tension problems. He thought he solved it by dialing in a bunch more crimp (he didn't) and then when he chambered the round the bullet was driven deeper into the case causing a spike in pressure.

It's always a good idea with the Sig to test neck tension by pushing a loaded round against your bench to see how much pressure it takes to push the bullet in.
Using a scale I have some combinations that won't move more than two or three thou under 80 lbs of pressure. Pick the wrong bullet or don't size your brass down enough and the bullet is easily driven into the case by the force of striking the feed ramp during loading.
 
#65 ·
You're exactly right. A big part of that issue, and not discussed enough, is the diameter of the shank on the lowly expander plug. Every body talks about too little or too much flair. Often ignored is the critical dimensions of the interior diameter of the case neck. That is a function of the expander plug assuming brass with some remaining life and a properly dimensioned sizer. NOE is serving this quite well with their extensive catalogue of M style expander plugs. Of course, they are of no use if one uses powder through expanders.

I use one size expander plug for jacketed bullets and a larger ("Cowboy") diameter for cast to get the correct seating force and therefore neck tension.
 
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