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Please help! MG42 fires only 1 to 8 rnds

Posted: Sun Apr 22, 2012 9:39 pm
by High Plains Wiking
I have a WW2 dated receiver MG that sometime in the past was converted up to .308. It was used by a reenactment group for years only firing blanks. No probs except for some stoppages common to blanks. I purchased the MG and fired belts of blanks through it, no problems. However, wanting to convert back to live FA, I bought live fire Steyr barrel,bushing,nozzle,MG3 top cover(with the spring assist),feed tray and recoil spring all new.The gun will only fire 1 to 8 rnds before stopping. The bolt always is forward with a live round in chamber,and the rnd in the pipe always has a much lighter pin strike than the fired cartridge cases. Any help would be much appreciated! I never changed anything in the bolt or buffer assembly from blank firing.Thank You for helping with this newb question!

Re: Please help! MG42 fires only 1 to 8 rnds

Posted: Mon Apr 23, 2012 9:14 am
by 42rocker
What ammo are you using. Most of the time this is the problem.
Good Luck

Later 42rocker

Re: Please help! MG42 fires only 1 to 8 rnds

Posted: Mon Apr 23, 2012 9:39 am
by JBaum
Take the bolt and grip apart and clean them. Lubricate the rails and the feed mechanism in the top cover. Did you check headspace? Did you put in an MG3 bolt? I recommend you don't run a 70 year old bolt in a gun that shoots 25 shots a second. An MG3 bolt is made of better steel. Is the anti-bounce spring in the bolt and is it facing the proper direction? Is the recuperator still strong (pogo test)?

Re: Please help! MG42 fires only 1 to 8 rnds

Posted: Mon Apr 23, 2012 10:25 am
by High Plains Wiking
Thanks for responding! Forgot to say that I do have MG3 bolt,{ not the heavier one } and anti bounce installed. My ammo is 7.62 x 51 NATO headstamped POF 90. I have just found out this is not the best ammo according to some ammo forums! I do have some cross stamped nato german and british ammo I am gonna try. Gun does pass pogo test and headspace test. TY AGAIN!

Re: Please help! MG42 fires only 1 to 8 rnds

Posted: Mon Apr 23, 2012 4:24 pm
by JBaum
If you have everything lubed, I suspect weak ammunition which doesn't produce enough recoil to properly operate the gun.

Re: Please help! MG42 fires only 1 to 8 rnds

Posted: Mon Apr 23, 2012 4:53 pm
by 42rocker
Or?? What is the size of the bushing? 11.5 is normally.

Later 42rocker

Re: Please help! MG42 fires only 1 to 8 rnds

Posted: Tue Apr 24, 2012 4:38 pm
by High Plains Wiking
My bushing is only about .355 or 9mm. I got it from RTG with the nose cone for MG3. Could this be a problem? Could you also please tell me if the buttstocks are naturally loose, mine can wiggle about when assembled on the gun. It is a wood one and I would like to replace it!

Re: Please help! MG42 fires only 1 to 8 rnds

Posted: Tue Apr 24, 2012 9:36 pm
by drooling idiot
I've run some of that Pakistani surplus before... its very not good. Had deep/shallow primers , OAL was all over the place.
Try some fresh commercial ammo.
http://www.sgammo.com/product/brown-bea ... -ball-ammo

Re: Please help! MG42 fires only 1 to 8 rnds

Posted: Tue Apr 24, 2012 11:50 pm
by High Plains Wiking
Yeah,I never should have grabbed that box of ammo. gonna try my German or British NATO stamped stuff this weekend.Thanks for all the good ideas!

Re: Please help! MG42 fires only 1 to 8 rnds

Posted: Wed Apr 25, 2012 8:43 am
by 42rocker
Good Luck and hope that you have fun, please let us know how it goes. A few pictures if you get the chance. Also the 11.5 from before was what I remember from 8mm.

Later 42rocker

Re: Please help! MG42 fires only 1 to 8 rnds

Posted: Thu Jul 12, 2012 10:39 pm
by BernieT
Sorry for the late reply ,,,similar problem i encountered,,,a recouperator, thats to stout will also cause this light strike, as i had a 19 lb one in my FA-42' and "tried a new one" that took 22 lbs to pogo test,,result was exactly what happened to you,,,re-installed the original 19lb(as measured with bathroom scale), and fires flawlessly 150 straight..!
just someting to check...Bernie

Re: Please help! MG42 fires only 1 to 8 rnds

Posted: Thu Jun 04, 2015 8:47 pm
by mg42jamesw1
I'm not meaning to renew an old post, but I could not find a better place to add this. I tested my recuperator using a bathroom scale. FA mg53 weighs 26 lbs resting on the scale. I then push down on the barrel bushing (muzzle down flash hider removed) until the bushing bottoms and the scale shows 45 lbs. The recuperator adds about 19lbs of force. Really not sure how to perform the POGO test, however I push on the barrel bushing and let go of the gun. It will jump off the floor about 1/4". Not sure if this means it passed or not. The gun has fired both 8mm and 308 ammo. I seem to notice a slightly faster rpm with the 308 ammo and smoother than the 8mm ammo. Could just be the surplus ammo, but not sure.