First things first. (hope the video works) http://smg.photobucket.com/albums/1003/ ... CF0155.mp4
Have 4 issues.
First the brp grip safety hung up the disconnector for some reason. I limited the belt to two rounds and the RSOs watching behind me never heard the double Took it out and it functions normally. Ill have to look into that.
Second out of 30 rounds I got a couple split necks on 50s Romo steel case. Primers look ok a bit of flow around the firing pin but not much.
Third is some trigger slap. Im going to try to limit the trigger travel and weld a stop on the forward side to see if I can remedy it.
Fourth is its shooting 2 feet high at 50yds. NO biggie Ill get to that last.
All in all happy as a clam it finnaly shot thanks to JEFF at Iron Creations LLC for his booster. I might try a smaller one even. The cases are getting beat to hell and flung as far as my RPK after hitting the bench
The shells do get beat up upon ejection. They twirl and hit the trigger guard. Shooting 50+ year old steel cases is asking for trouble. How did the headspace check? A larger booster hole may tame the extraction down a bit.
Well I didnt headspace it yet. The bolt matches the barrel and camming piece. Ill get a headspace gauge asap. And the Romo is 1974 vintage not 50s like I thought.
Now work on a few of the small items. Headspacing should have been done first as barrel do wear out. But seems no major at this time. Just check it asap. Normally someone talks about his great idea of adding some rubber tube to the front of the gripstick to save the brass from some dents but I'll bet that he was thinking about the next German translation he is going to do.
Nice video that worked also. Thanks and way to go. Good Feeling.....
Also raising the front sight is what needs to be done to lower where the bullet hits. After checking to see that the rear site is in the lowest position.
Ok so it passes the field gauge. Bolt head wont go into the locked position with it. Looks like its well within tolerances based on the amount the rollers move which is very little. So the split cases might be generous chamber with steel ammo? Bolt slap was fixed when I fixed the safety. Any chance those cases might split all the way?
Yes, it can split all the way. Steel cartridges corrode from the inside. Beside that, steel is not self-lubricating like brass. The extraction occurs before the shell has a chance to shrink back to normal size, so the stress on a shell in a 42, especially a steel shell, is extreme. Make sure your chamber is clean. An oily brass brush on a cleaning rod with an electric drill will make sure of that.
One split shell like that would convince me to stop shooting that ammo, but you get to make your own decision on that.
I picked up a smaller booster and simultaniously found that my buffer was mis aligned causing the bolt to bind. So now I believe im overgassed as the bolt is bottoming out on the buffer spring. Is it possible that it could cause the shells to eject a bit sooner than they are supposed to? Ive still got the 13.9mm booster. What ammo do you shoot in your FA 42s?
I shoot 8mm ammo that I load (or reload), and modern .308 surplus.
Shells can't eject at any other time other than when the rear of the bolt hits the buffer head. It's the excess force from severe recoil caused by a small nozzle that can be damaging.
The nozzle shouldn't be any smaller than necessary to make the gun cycle with the ammunition you're shooting at the time. Any smaller isn't doing any good, and can beat the gun to death by damaging the parts from the excessive impacts.
Took it out and it functions normally. Ill have to look into that.
