AK47 peening/ Mushrooming. Is it bad?

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Brandon B

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hello all!
I had a quick question about peening and mushrooming of the tail on the BCG of an ak47. C39v2 to be exact.
There’s one I really want to buy, from a trusted seller.

I’ve heard mixed things about this. Some guys say it’s not a big deal at all and the tail eventually will harden, without any future mushrooming. Some say it’s death.

What do you guys think? I’ll upload a few photos to show you what it looks like after about 300 rounds.
Also when I get home I’ll check my AKs and see how they look as far as mushrooming. Assuming my Arsenal’s don’t have any, but maybe my century RH10 (which is basically a dressed up wasr) has some?

Basically I just want to see what you guys think about mushrooming, and if I should steer clear from this or not worry about it.
Check out the photos
Thanks,
B
 

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Disclaimer: I have very little personal experience with AK's but have researched them quite a bit.

From what I best understand and what makes sense to me is it is caused by a difference in metal hardness of the hammer compared to the carrier tail. It is common to see deformation on all tails, what I've been told is a slow steady deformation over lots of rounds is to be expected. Fast deformation of the tail without many rounds is an obvious cause for concern. Lots of people spend time trying to smooth out the contact point of the hammer and tail to reduce friction or uneven contact, but it seems most say it helps with smoothness but not so much on slowing deformation.

The second picture shows what I would consider excessive flattening after only 300 rounds, again this is just from what I've researched as it is common for people to check the tail when shaking down a rifle. Watch some of Robski's AK videos on youtube he does a 5000 round test on several different AK's and he shows the tail peening progression and gives his expert opinion on what is excessive and what is normal.

Here is a link to the youtube videos of Robski and MAC performing such a test on a C39v2


Hopefully someone with more AK experience can add to this conversation.
 
I've been looking at buying a PSAK 47 Gen 2 now that they have forged carrier rather than cast (like their Gen 1's), it has seemed to help with the longevity based on reviews I've seen.
 
Posting for interest. I have one of the dreaded RAS47s from Century that hasn't started showing yet.

It’s pretty hit or miss I guess. I’ve had wasrs and PAPs that didn’t have it
 
Disclaimer: I have very little personal experience with AK's but have researched them quite a bit.

From what I best understand and what makes sense to me is it is caused by a difference in metal hardness of the hammer compared to the carrier tail. It is common to see deformation on all tails, what I've been told is a slow steady deformation over lots of rounds is to be expected. Fast deformation of the tail without many rounds is an obvious cause for concern. Lots of people spend time trying to smooth out the contact point of the hammer and tail to reduce friction or uneven contact, but it seems most say it helps with smoothness but not so much on slowing deformation.

The second picture shows what I would consider excessive flattening after only 300 rounds, again this is just from what I've researched as it is common for people to check the tail when shaking down a rifle. Watch some of Robski's AK videos on youtube he does a 5000 round test on several different AK's and he shows the tail peening progression and gives his expert opinion on what is excessive and what is normal.

Here is a link to the youtube videos of Robski and MAC performing such a test on a C39v2


Hopefully someone with more AK experience can add to this conversation.



Thanks for the input. It kind of seems excessive to me too. I have far more rounds down range on my wasr & RH10 and don’t recall seeing this. I still haven’t broken it down to check that exact part of the rifle, but every time I get back from the range I do a detailed strip and clean. I feel I would have noticed this on my others
 
None of my Saigas show that peening. Nor did the Romanian.

M
 
If the price is right, I wouldn’t worry about it myself. Off the top of my head I can’t imagine what sort of failure to function that would cause that some kid in Darfur couldn’t fix.
 
LOL. No idea why I laughed so hard @ that hahaha.

But anyways. What I’ve heard is that once it’s like fully mushroomed, and I mean beat to s**t almost non existent, it can cause firing while going into battery. No idea if that’s true or not.
Maybe somebody else on here can touch on that?
 
If you're talkin’ so beat to s*** that the firing pin hole is peened over enough to cause the firing pin to stick, then yes, it may slam fire. In which case, said kid in Darfur would just replace the bolt with one from another gun that couldn’t be fixed with a brick and a screwdriver.
 
If you're talkin’ so beat to s*** that the firing pin hole is peened over enough to cause the firing pin to stick, then yes, it may slam fire. In which case, said kid in Darfur would just replace the bolt with one from another gun that couldn’t be fixed with a brick and a screwdriver.

Hahaha

Hilarious. Ok so seems like you think it’s good to go then
 
C39v2 and any American commercially made AKs are of questionable quality. Stick with ex Com bloc Kalashnikovs. As long as people keep buying subpar quality AKs by Century, IO, or other Murican manufacturers, that’s what they’ll continue to produce; a subpar product.
 
The tail end isn't the primary area of concern with american made BCGs. Instead you want to look specifically at the locking lugs. If the lugs are deforming or chipping it can generate excessive headspace. Century will replace a deformed bolt at no cost, but you do have to send them the entire rifle as headspacing needs to be set. Turnaround is about a month.

The attached pic was an earlier RAS bolt with about 600 rounds fired. Peened with small chip missing. Was repaired under warranty.

It was sold after the repair. Honestly the most accurate AK I ever seen in real life. With scope and steady rest would print nice 1-1/2 inch groups at 100 yards with tula ammo. No telling what it might have done with good handloads but alas my son likes volume of fire and replaced it with a very durable and typically inaccurate WASR.
 

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C39v2 and any American commercially made AKs are of questionable quality. Stick with ex Com bloc Kalashnikovs. As long as people keep buying subpar quality AKs by Century, IO, or other Murican manufacturers, that’s what they’ll continue to produce; a subpar product.

Very true. Although I like certain century AK’s like the WASR and RH10 which I own both, I also have a few Arsenal’s.

The wasr and RH10 are both great guns made by century. Never have I had a problem with either of them, and they function just like my Arsenal’s. I also got to checking on both my Arsenal’s and my century’s and I have little to NO sign of peening/mushrooming on the tail of the BCG. The RH10 actually has ZERO peening. I noticed it’s likely because of the trigger they put in the RH10. When I pop off the top cover of my RH10, and slowly rack my bolt, I see that the tail doesn’t even touch the hammer. On my wasr it slightly rides on it for maybe 1/10 of an inch, and on my Arsenal’s they touch even longer than that. Still no peening. Maybe they had matching strength material when they built it, which shows Arsenal’s quality to be worth the price in at least one aspect
 
The tail end isn't the primary area of concern with american made BCGs. Instead you want to look specifically at the locking lugs. If the lugs are deforming or chipping it can generate excessive headspace. Century will replace a deformed bolt at no cost, but you do have to send them the entire rifle as headspacing needs to be set. Turnaround is about a month.

The attached pic was an earlier RAS bolt with about 600 rounds fired. Peened with small chip missing. Was repaired under warranty.

It was sold after the repair. Honestly the most accurate AK I ever seen in real life. With scope and steady rest would print nice 1-1/2 inch groups at 100 yards with tula ammo. No telling what it might have done with good handloads but alas my son likes volume of fire and replaced it with a very durable and typically inaccurate WASR.


Yes I see what you’re talking about. Thank you for the photo and the response. I’ll have to dig into that and check it out.
 
Very true. Although I like certain century AK’s like the WASR and RH10 which I own both, I also have a few Arsenal’s.

The wasr and RH10 are both great guns made by century. Never have I had a problem with either of them, and they function just like my Arsenal’s. I also got to checking on both my Arsenal’s and my century’s and I have little to NO sign of peening/mushrooming on the tail of the BCG. The RH10 actually has ZERO peening. I noticed it’s likely because of the trigger they put in the RH10. When I pop off the top cover of my RH10, and slowly rack my bolt, I see that the tail doesn’t even touch the hammer. On my wasr it slightly rides on it for maybe 1/10 of an inch, and on my Arsenal’s they touch even longer than that. Still no peening. Maybe they had matching strength material when they built it, which shows Arsenal’s quality to be worth the price in at least one aspect
WASR and RH10 are NOT made by Century, they are imported by Century. Both rifles are made by Cugir in Romania. That is why they are good to go rifles. They may not look as pretty as the RAS47 or C39, but they are made properly with forged trunnions and other parts, not cast like RAS or CV.
 
Why bother with a US-made consumer-grade AK of questionable quality (and know issues with bolt carrier tail mushrooming), when you can just buy a proven foreign AK made in a Comblock factory?
 
WASR and RH10 are NOT made by Century, they are imported by Century. Both rifles are made by Cugir in Romania. That is why they are good to go rifles. They may not look as pretty as the RAS47 or C39, but they are made properly with forged trunnions and other parts, not cast like RAS or CV.

I concure! Love my century.
 
WASR and RH10 are NOT made by Century, they are imported by Century. Both rifles are made by Cugir in Romania. That is why they are good to go rifles. They may not look as pretty as the RAS47 or C39, but they are made properly with forged trunnions and other parts, not cast like RAS or CV.


Yes that’s what I was getting at. It’s still sold by century although it’s a cujir made
 
Why bother with a US-made consumer-grade AK of questionable quality (and know issues with bolt carrier tail mushrooming), when you can just buy a proven foreign AK made in a Comblock factory?
I totally agree with this statement and his is what I did. I love my Combloc rifle.
 
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