Wolf 7.62x39 not cycling full auto?

[SB88LX]

Went to a machine gun shoot yesterday, and had the chance to shoot a full auto AK (I have a semi-auto Vector). The 154gr Soft Point and some of the 122gr hollow point failed to cycle in the full auto. The first shot would go off without a hitch, but the next round would be sitting in the chamber with a dented primer. After re-chambering the dented primer rounds, they would fire, but the next round did the same thing. What would cause a soft primer strike, which i'm assuming is what happened, in an AK? I was able to bump fire my AK with the 122gr FMJ 90% of the time, and the full auto liked it as well. Anyone who has heard/experienced this please respond.





PS, full auto rocks

 

[pcf]

LIES....ALL LIES AK47's can not malfunction.

I read on the internet about a guy who: placed his AK47 in a carbon fiber crucible, heated it to 10,000 degrees celsius, threw it in a pile of sand, picked it up 30 seconds later, slapped in a magazine, and let it rip on full auto. No malfunctions, and unlike the Matty Mattel toys, the wood on the AK protected his hands from burns.

I have no idea, sorry.

 

[SB88LX]

Heh, dont worry, the wolf 122gr HP wouldnt fire period in this one guys AR with a 7.62 upper on it. I don't know if the primers are excessively hard or what.

 

[MechAg94]

10,000 celcius? (18,000 F)
I guess the sand was actually a sand casting he used to cast another rifle.

 

[garrett1955]

making glass anyone???? LOL

 

[beerslurpy]

Maybe a badly timed auto sear? It sounds like a gun that is slamfiring. A properly done FA conversion should go off every time like the first. If it is failing on subsequent shots, it is almost certainly the timing of the hammer.

Did the guy even have an auto-sear? It sounds an awful lot like some kind of searless ghetto job (zip tie the disconnecter out of the way or something). Did he have papers for the gun?

And wolf should cycle FAs just as easily as it does semiautos. Getting an AK to shortstroke with even subsonics is very hard unless you have a very crappy (oversized, sticky, whatever) recoil buffer that is blocking the bolt from travelling properly. The AK gas piston is so broad that getting it to not cycle is nearly impossible unless you weld the gas port shut. Remember, his gun WAS cycling, it just wasnt putting enough pressure on the firing pin after the first shot. The only possible cause I can think of for this to happen when first shots work is that the hammer is moving forward too quickly and riding against the firing pin as the bolt closes. This would dent the primers without setting them off reliably.

 

[SB88LX]

Papers for the gun? Couldn't tell you, but he is a class III dealer so I imagine it was set up properly, i'm not sure. About the bump firing though, is it a common occurence for the trigger to be pulled too early as to interfere with the disconnector? The rounds in my gun also had dimpled but unfired primers on the unsuccessful bumps.

 

[beerslurpy]

Dunno, but there is nothing to stop it from happening, as you lack anything to delay the hammer.

Slamfire condition:
1. Gun fires.
Bolt goes back.
Hammer is depressed and engages semiauto-disconnector.
2. (Trigger is released. Semiauto disconnector is released. ) OR
(Semiauto disconnector is missing/retracted/etc)
3. Trigger is pulled.
Trigger hook is released.
Hammer moves forward.
4. Bolt moves forward (with hammer riding behind it)

The job of the auto sear in the AK is to prevent the hammer in step 3 from occurring before step 4. The idea is for the bolt to be completely closed before the hammer reaches the firing ping. If it gets there too soon, the firing pin is pushed forward, but without sufficient power to break the primer.