M*CARBO Brotherhood

Sub 2000 cratered primers

I am getting cratered primers with all types of ammo in my brand new S2K. What’s up? The same ammo fired in my Bersa TPR9C does not show signs of over pressure.

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post a pic of thei primer.

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and welcome to the show!

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@ypsigypsy welcome to the forum

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Cratered primers as in firing pin drag? That’s usually caused by the firing pin not having time to retract all the way before the case gets ejected - that bolt head slams back pretty fast. I’m not seeing drag on any of my Subbie’s casings. Like @cico7 says, post a pic.

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Nobody should be seeing drag marks because the S2K is a blowback design. Primer drag happens in locked breech/tilting barrel designs because the chamber end of the barrel unlocks and starts to tilt downward as soon as the slide starts retracing. If the firing pin doesn’t have time to fully retract behind the breech face, it drags on the primer and makes that mark. The barrel is fixed in blowback designs, so that’s why there’s no primer drag marks unless something is seriously wrong.

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Exactly, but if there’s any hint of it, it might mean the firing pin isn’t retracting and it’s possible the gun may slam fire (ala SKS with a stuck pin). @ypsigypsy please get us pics of the casings, and at the very least take the firing pin out of the bolt head and clean it and its channel, along with checking its spring.

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Has he been back since he posted?

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I don’t think he’s returned yet.

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sorry about the delay of posting primer picture!! !

I don’t think the photo came out.Hey I’m a old guy who learned to write letters and include a Polaroid picture,this email,chat room stuff is new to me. If you could see the photo it would show two rows of fired cases. the top row fired in my Bersa TPR9C with normal primers and the bottom row of cratered primers from my Sub 2000. Is there enough clearance around the firing pin in the bolt face to allow the primer to push into the gap? Again sorry about the slow reply. I live in rural northern Michigan and our Governor has finally allowed me to get back to work.

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The photo is fine and I see what you mean. I’m out of my league here.

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Are these reloads? I have seen this in HOT hand loads.

I searched Cratering Primers on google after I made my statement. I think Google agrees with me. (it must be true right?)

Normally, cratering comes around from having too much pressure in a hand load and when the case contracts, it hits the bolt face hard enough to bounce the firing pin back and material flows into the firing pin hole.

The only thing that comes to mind (other than excessive pressure) is an oversized firing pin hole.

Send the bolt to Gre-Tan Rifles & have it bushed & your problem will be solved. If yours is like mine was, the firing pin hole actually had a tiny radius, like a bevel.

Rate your Bersa…what do you think of it?

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The Bersa TPR9C is a easy gun to shoot well.I am left handed so the large bilateral controls are what made me chose it. I am very glad I did. The DA/SA trigger is smooth with a short fast reset,much like the Sig SRT option, the metal frame adds a little weight which I don’t mind, so far I have put approx. 3000 rounds thru the gun with out failure of any kind. I pushed out the rear sight and added a ADE 6 moa green dot optic on top of a UTG slim line plate.This one is a keeper.

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@ypsigypsy Welcome to the forum.

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If the bolt is binding and slowing down mid-way in the tube, while cycling back, could it cause that? Anyone???

@ypsigypsy It is something easy to check, and worth looking at, even if it’s not the cause of your issue.
Take a look at these threads.

Got to go out in the back woods and do some shooting. While the S2K cratered every primer it still shot great. Went through about 200 rounds so now I get to practice the cycle of life,because I shoot I get to reload, because I reload I get to shoot…

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@ypsigypsy

I just want to be certain you understand loads that are/were safe in pistols “can” go over pressure with 16" of barrel to build pressure.

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I did not know that. I see craters in factory standard pressure ammo as well as my mild hand loads.

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I have installed the deflector and recoil buffer on the S2K and it is more comfy to shoot. I hope I did not pay $10 for a garden hose washer but it does take a bit of sharpness out of the recoil.The deflector is a MUST for left handers like me.

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@ypsigypsy Welcome to the forum.
I’m a lefty as well and really like the deflector including that it definitely assist me in keeping track of casings.
I’m a bit slow on installing the recoil buffer (garden hose washer LOL, good 1) and also the butt pad.
Thought to do them at the same time.
Glad to hear about the recoil buffer taking a bit of the sharpness out of the recoil.
Cheers,

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