drive stud keeps breaking wtf

[fourfifths1911]

this is the second time this has happened . I thought my bfa was to small at .156 so i installed one at.172 . So i think the bolt is slaming the buffer too hard . I made some new ones out of tool steel just have to install one. It always cracks in half were the firing pin hole is drilled. Btw i'm using blanks guy two piece barrel , pbb bolt, brp grip stick, and pakistan 308 blanks.

[Blanksguy]

Is your "drive-stud" welded to the carrier (?)....or free to pivot like a normal MG42 feed-roller on the top-rear of the bolt-carrier (?).

Does your feed-mechanism have full motion to move completely left and right without restrictions (?).

Next.......check to see if your "buffer-head/tip" hits the parts too hard when it recoils....possibly the firing-pin retainer/extension may be made incorrectly (?)....such as the location of a "collar" or stop for spring or something (?).

Each of the SA42s is different.....between manufacturers....and even in fire-control-groups. Each will have to be diagnosed separately.
I know that it won't be the 2-pcs. Blank-Barrel-Assembly....and it won't be the Blanks.......possibly the adjustment for restriction may be too small allowing for too harsh a recoil (?).....how did it fire "LIVE-AMMUNITION" (?).

Last, now if I could just get someone in Michigan to sell-to-me an SA42 built on a 3-cut WWII German-Receiver......or build my SA42 so that I would have a "test-bed" other then my C&R MG42.....I'd be set.

The other "challange" is that it would really be nice if guys/reenactors would post more about what BFA Hole-Size they are using with what surplus-blanks, and some of their other modifications to their SA42s.....we would be able to give out more information. Till then, ......we try to help where we can.

Regards, RichardS in MI.
Blanksguy2001@chartermi.net
PS: Please post information when you get this "challange" figured out. It will help others.

[drooling idiot]

this is the second time this has happened . I thought my bfa was to small at .156 so i installed one at.172 . So i think the bolt is slaming the buffer too hard . I made some new ones out of tool steel just have to install one. It always cracks in half were the firing pin hole is drilled. Btw i'm using blanks guy two piece barrel , pbb bolt, brp grip stick, and pakistan 308 blanks.

Sounds like a good excuse for a range trip to me.

[fab]

how tall is your barrel guide a 50mm one??
if your barrel guide is a 45mm lone, try with a 50mm.

[fourfifths1911]

well it seems to run with the .170 bfa but better with the .156 and ive only bin using pof .308 blanks and it live fires fine. Di we should go to the range just let me know whats good for you i know your busy with the twins.

[fourfifths1911]

Fab what part are you refering to

[fab]

This part;


more long it is , higher will be your cyclic rate.

[Blanksguy]

.....with the longer "Barrel-Bearing".....you will also increase the speed of your Bolt for firing "Live" ammo......

"but"......

....when using the 2-pcs. Blank-Barrel-Assembly, all the Barrel-Bearing does is center/support the muzzle of the barrel and nothing more. You see, the only part of the 2-pcs. Blank-Barrel-Assembly that moves is the rear-section. The front/longer section is held in place by the "flair" at the rear of the barrel by the rear-barrel-stop......as shown in the photo below.

Last.....I am making another run of .308 cal. (7.62x51mm) 2-pcs. Blank-Barrel-Assemblies along with more for the MG34/SA34 this weekend. This should be my last "run" of these.
There are a lot of reenactors that want to run those cheaper "surplus" Blanks in their guns......and this is the "ticket" to firing more Blanks at less costs.

Regards, RichardS in MI.
Blanksguy2001@chartermi.net