www.MG42.us

I made a new bearing on the lathe today, and attempted to screw the flash hider on, and found that it won't completely thread on, and seat against the shoulder! I will post some pics showing what is going on... Part #2 is preventing the hider form seating. Should part # 2 float in the flash hider? Or be solid?

part #2 ??

I'm trying to post pics...

ah i see

...edit... just grabbed one of mine and it does as you describe.. it seats aganst the bushing

just grabbed five more and they all do... I never paid attention to that before. It makes sense though as the bushing is used to constrict the exit hole and has no need to move

Nice start on the support bearing.

Flash hider on my original doesn't seat against flange. Remember this is where it is crimped on. My receiver overhangs the flange a bit.

some pics for refrence

Does the booster ever loosen up and begin to unscrew during firing (at least if a custom bearing is not threaded correctly)?

no the flash hider is held from rotating by the finger piece shown on the right side of none123's second picture . it locks into the recesses cut around the booster.

The flash hider should be screwed on all the way, then backed off until that finger piece engages one of the slots and locks the flash hider in place, preventing it from getting looser or tighter. The finger piece is spring loaded to keep it engaged. After shooting, remember to disassembly the flash hider, remove the recoil booster, and take out the barrel bushing (after removing the barrel of course). These parts were originally soaked in kerosine and brushed or scraped as required to clean off the carbon deposits. Clean these parts thoroughly after every trip to the range.

Thank you guy's very much for the help, the good pics and the compliment....Now for another question! When I go to weld in the bearing, how should I go about positioning correctly? Should i set it in so the recouperator puts tension on everything? Or should I set it to just aloow the barrel to removed?? I don't know what to do since my kit had no rear reciever pieces, and no barrel bearing!!!! Any thoughts, or help??
Gary

lets use this picture as a reference .
now it shows OAL , but you have a custom bearing so you'd need a length from the shoulder before the threads to the same dimple against where the cam section rests .
that measurement is 21 5/8" , go slightly heavy as its actually metric.
also be aware that you will need to time the keyways correctly before welding to allow the barrel bearing to fit in at the correct orientation.
have you heat treated the new bearing or is it machined from hard enough steel to take the abuse?

Thanks for the measurements and pic! Awesome! The new bushing/bearing is made from 4130. I may pop it i the furnace and heat treat, but I may not shoot this gun too much ( Just like my 1919a4) I do more smithing and building than shooting for some reason Thanks again for the help!!!!!!!

Just as a friendly reminder, make sure that the barrel bearing has the open ended opening for the barrel to fit into is facing the right side of the reciever so you can postion the new made reciever bearing for the slots.

Great info guys! Look, I'm am absolutely embarressed about the bearing thing. I'm an idiot

From the parts that I do have, I figured out that the relifs have to face to the right. i also noticed the "Master Spline so it can only be assembled one way! Pretty neat stuff! Guess that cuts down on confusion in the battlefield! HAH! So does anybody know where I should postion the bearing for proper operation? I plan on tack welding it in with the bolt locked up to the barrel extension, barrel forward, as if it was in battery, with everything snug. Then I will pull the bolt back with the charging handle, and see if I can remove the barrel?? Sound good?? Yes, no?
Gary

garyh wrote: So does anybody know where I should position the bearing for proper operation? I plan on tack welding it in with the barrel forward, as if it was in battery, with everything snug. Sound good?? Yes, no?
Gary

sounds good lets run down the check list for anyone else .

drop the barrel bearing into the NEW bearing sleeve ,
insert the barrel into the shroud
put a thin (1/16th" or less) washer as a spacer into the bearing between barrel's muzzle and inside of the bearing.
Now push the barrel forward in the shroud until the collar of the locking piece hits against the barrel stop which is riveted inside the shroud by the barrel door.
push the bearing and bushing (with washer) back onto the barrel as far as it will go without moving the barrel away from the internal stop.
that is your length.
check and double check your orientated so that the barrel bearings cut out is on the barrel door side and tack weld it in place for testing.
you don't need to involve the bolt or any other parts at this stage .

: edited to make more detailed instructions :

I finally got it done! Hope it works! Broaching the raceways was a BITCH, but cam out good!