Breechface erosion STI Trubor

[Warfarin]

Alright, back from the range managed to fire 37 rounds before the hammer will no longer lock back and work.

But link for federal SPP:

http://s200.photobucket.com/user/Rightboy/media/IMG_52541.jpg.html

Link for Win SPP:

http://s200.photobucket.com/user/Rightboy/media/IMG_52551.jpg.html

Winchester looks the best. Now I gotta figure out why the hammer won't lock back.

[Steve RA]

Yes. the WW primers look the best. Another minor problem is that your firing pin strikes aren't centered. It isn't off enough to really affect ignition, but should be centered. Something else they can look after if you send the gun back in.

[CocoBolo]

Benny probably knows more than all the rest of us combined. I used up 20,000 SPM Winchesters last year, behind Silhouette 7.7gr to 8.1gr in 9 Major, no erosion.

One thing that no one has fathomed here is the brass, I only shoot once fired brass one time! Yeah, you heard me right, the why is that in 9 major the primer pockets take a lot of abuse!

If you are loading 9 major in the same brass a bunch of times, chances are the primer pockets are streched out. My good friend that works for Daswon says you can reload them twice, but my thinking is why take a chance, well shuks I have an extra slide, naw I think I'll build another gun when I win a frame.

I did't use a caliper to figure this out, after two or three loadings, I went to empty the tumbler and there were all these primers in the corn, once things were seperated I noticed that there was a lot of brass with no primer. Dang that tumbler got some powder. So I load some up, put them in a bag and shook it, guess what a bunch of primers in the bag and powder.

Benny said slower powder, a few choices here, AA#7, yes it works 10gr w/124/5gr bullet 1.180, 3N38, Silhouette, HS6.

The federals are flow thru look real bad, and the Win pictures look like maybe you used a reamer or swagger, definately not too much pressure but there is too much space around the outside edge of the primer. Try CCI small pistol or bump you load up to 7.0g of Autocomp. A truebore need an axx ton of gas to flatten out so more might just make it shoot better.

One thing missing in your post is the OAL you are using, it should be > 1.145 and normal is 1.165 or longer, shorter well could be a problem.

Edited July 15, 2013 by CocoBolo

[Warfarin]

I will try to find some hs6.

Edit: Nope not gonna have much luck. I will keep the WIN SPP then increase OAL to 1.175 then increase Autocomp to 7.0 and see the results.

Edited July 15, 2013 by Warfarin

[CocoBolo]

I will try to find some hs6.

Edit: Nope not gonna have much luck. I will keep the WIN SPP then increase OAL to 1.175 then increase Autocomp to 7.0 and see the results.

Do a search for breach face errosion here, you will notice that it happens when using Minor Loads with Magnum Primers.

I will try to find some hs6.

Edit: Nope not gonna have much luck. I will keep the WIN SPP then increase OAL to 1.175 then increase Autocomp to 7.0 and see the results.

Those primer pictures are ugly, Don't increase the charge. If you have one scale and it is electronic, have a friend check it against his scale. I've used Autocomp @ 7gr no issues, HS6 at 8.3gr, AA#7 at 10gr. All with SPP (mostly CCI but some win, and Lots of WSPM). Weigh your bullets as well, if they snuk some 160gr pills in with 124gr yeah that could be an issue. OAL is critical but some tupperware (glock) shooter have run them short and lived.

[Warfarin]

I am thinking it could be the brass... Well looks like I'm gonna try to make it shoot factory crap in minor. Not really in the mood to dish out big bucks for starline brass.

Edited July 18, 2013 by Warfarin

[cylindrically challenged]

• I had this problem before with some bad remington primers. If you looked real close at the fired primers you could see very fine cracks in the primer its self. It wasn't every primer, but the primer would have a small split at the corner where the face of the primer was bent to form the sides of the primer. This allowed high pressure gas to escape from the primer and cut my breech face. Your photos show gas cutting around the primer pocket. The high pressure gas is either escaping out of a loose primer pocket or out of the primer its self. If you have any of the fired rounds left over from the breach face eating rounds, give them a good look over for small soot stains where the high pressure gas was escaping and go from there. It could be a bad batch of primers or just too much pressure for the primer pockets to hold. Like Benny said, slower powders could reduce your pressures. Also, push your overall length as far out as possible, this too can lower you case pressures. I load my 9mms on a 2011 platform clear out to 1.240". That way my pressures are no worse than a .38 Super. And they feed better from a 1911/2011 platform at this length. If your barrel throat will not accept a round of this length any good gunsmith could throat your barrel to accomplish this.

[CocoBolo]

Hold the phone, I pickup and shoot any thing that don't stick to a magnet. It could be the light in the pictures but they just don't look right. (I don't pickup my own), mostly I buy once fired.

Trade some of those Win SPM's for some CCI small pistol and see how they work for you. Federal are too soft for 9 major.

Edited July 18, 2013 by CocoBolo

[Blujay291]

Try rifle primers solved my issues

[Blujay291]

That errors ion looks worrysome

[donnyglock]

I agree. I have also had good luck with Wolf/Tula sp primers with Silhouette in 9mm major.

[amish_rabbi]

Did you sent sean at freedom ventures an email? He is the STI distributor and warranty place, STI is one of the few brands in canada where warranty work is fairly prompt, not "you'll have your pistol back in a year" like most others

[BlackBuzzard]

Seems I break all the rules and suggestions here.......brass gets used over and over, federal primers, win primers, sr win, with 9major, using hs6, autocomp and VV.

But I have a perfect looking break face on my STI.

There is a process call plasma spray that greatly enhances the base metal's resistance to flame cutting.......seems STI could afford this equipment.

FWIW my glock 34 production unit has significant breach face errosion and I feed it a diet of about 90,000 rounds of factory CCI blazer.........back in the day i could pick up that stuff for $3/box at academy, so I shot the snot out of it.

BB

[Warfarin]

Yah I talked to Sean he is very helpful. I sent it back to him to fix the hammer not locking back which happened during testing new primers. I bought what was supposed to be once fired brass, but I am trying to find out if they swaged or reamed the primer pockets.

I deprimed some factory ammo and the primer pockets generally look quite clean after depriming. The stuff I fired after depriming has no visible primer flash at all on bottom of the case, I looked over ~200 rounds and there is nothing, but after depriming it doesn't look like the factory ammo after being deprimed. Some looks the same and others look like there is some burning occurring around the primer walls (but not visible on the outside of the case). It must be a very small amount of gas escaping out of the primer hole.

Edited July 18, 2013 by Warfarin