Issues with getting a M53 to run right

[TimMcBride]

First Post, hi.
Got some questions. I am an 07/02 FFL, SOT but this is my first venture into the MG42 game.

I recently built a Post Sample M53 and have been having some issues getting it to run just right.
Right now I can get the gun to run in 8mm with a 10,5mm Flashider/Booster combo that was meant for a MG1 conversion. I am using Yugo ammo, which I have been told is not the greatest but it's that or Turk, and I've seen enough warnings here not to do that.
I really don't think this is right setup, however it does run and does not show any signs of the gun getting beat up. I converted the setup from a Wiselite gun, so the receiver is an inch longer. I am running a brand new recoil spring.
The gun will also not run in 7.62 reliably, it has ejection issues, or hangs up. From my reading on here I think I may need a 9.5mm booster but don't know where to get a booster in that specific size(All the sites just sell boosters).

Thanks for any help.

Tim

[salt6]

[42rocker]

Welcome
That's interesting converting a SA wiselite to Full Auto. Well you have the SOT to do it so more power to you.
Jbaum of

http://www.germanmanuals.com/

has a MG42 Gauges for sale to double check your feed angle to see if that is a problem. I'm also sure that others will add more to this there are some good FA folks on this website. Also you already have addressed your ammo issues as that could be your problem also.

Welcome

Later 42rocker

[JBaum]

If you can't find the nozzle size you want, just weld and redrill the hole in a nozzle that isn't what you want. The nozzle controls the amount of recoil. If the bolt doesn't hit the buffer hard enough, it doesn't eject correctly. Making the hole in the nozzle smaller forces the barrel rearward with more force and speed.

Lubricate the bolt rails and top cover parts with some light grease to reduce friction.

Check the recuperator for proper function. Make sure the barrel moves freely in the jacket. You've already questioned your own ammo. How does is run with fresh 8 mm ammo?

Recommended reading: HDv 216/6 and the MG42 Armorer's Repair Manual.

[12thWaffenSS]

My M53 won't run right either. Mine runs to the left. <rimshot>

Thank you, thank you. I'll be here all week. Try the veal.

[DARIVS ARCHITECTVS]

My M53 won't run right either. Mine runs to the left. <rimshot>

Thank you, thank you. I'll be here all week. Try the veal.

[42rocker]

Ok, it's training lots and lots of training then if you put it into a lafette tripod it will not run left or right...

Listen to jbaum or the rim shot guys, your call.... Buy the books from jbaum also.

Later 42rocker

[Bil]

Now I may be wrong,BUT- the wiselite receiver was made longer as was the buffer tip.I believe this was so a full-length spring could be used with the converted bolt,which is longer,hence the usual home-biult shortened spring.I believe it was Gordie K that worked on this problem.Thus,is you are running these parts,the inside dimentions,lengthwise,will be off.It will affect bolt travel and where the ejector hits.I would check this out

[Blanksguy]

Tim,

What is the length of your Barrel-Bearing (?). PLease give the measurement to the closest ._ _ _ "
Note: The Germans made two different length Barrel-Bearings......but with your gun being a Wiselite-M53-??...I am not sure if Wiselite incorporated the used Barrel-Bearing...or made something new.(?) The longer of the two would hold the cycling-pressure in the system a split-second longer. This would also raise the RPM slightly on a gun running the shorter Barrel-Bearing.

Regards, RichardS in MI
US Army, Retired
Blanksguy2001@chartermi.net

[TactAdv]

If you can't find the nozzle size you want, just weld and redrill the hole in a nozzle that isn't what you want. The nozzle controls the amount of recoil. If the bolt doesn't hit the buffer hard enough, it doesn't eject correctly. Making the hole in the nozzle smaller forces the barrel rearward with more force and speed.

John is quite correct on the ease of welding up the booster nozzles and reaming to a new size.....very easy and no issues.

I can't speak to the full range of issues inherent in converting a semi-auto, extended, receiver to a Postie; myself, I'd just weld on a "nose piece" extension sleeve (ejector ram) onto the buffer face, taking up the extra 1" that way, though that may result in its own problems, but since buffers are cheap it might be a place to start.

One of the things I'd gently point out about being an inherent problem/limitation of delayed blow-back, roller-locked actions is that they do NOT respond well to pressures(recoil impulses) over/under what they were designed to properly function with. The action design works due to a carefully calculated mathematical relationship of vector forces trying to simultaneously force the rollers outward, and the locking piece backwards ("opening the bolt head"). A higher recoil impulses, the lateral vector is stronger, hence the rollers stay "locked" (actually, "biased") outward, as pressures/recoil impulses drop, the rearward vector force overcomes the lateral and the locking piece retreats.

All of these vector forces are calculated for a set of given parameters when the gun was designed (around a certain known ammunition). Change anything in that equation, and you introduce problems along one or more of the vector force pathways.

The main problem with roller-locked actions being exposed to recoil impulses larger than expected, combined with ANY amount of differential roller movement, is that they will tend to begin to incrementally peen and work harden one or both of the locking recesses that the rollers seat into, causing elongation or wallowing of the recesses, opening up the distance for them to move into which alters the actions solid locking effect, increasing the tendency to hammer the recesses, etc., etc., all in a vicious circle. (H&K allows for this in their modern guns by supplying two sets of "oversize" rollers to install into the action as the gun wears and ages (AND THEY ALL DO), past a certain wear point, the gun is literally meant to be disposed of).

On the MG42-style locking seats, there are no easily available fixes. "Oversize" rollers simply do not exist, nor in fact were they intended to exist; for the MG42-type guns the locking recesses themselves were easily exchangeable via exchange of barrels with attached extensions. The main issue with exposing the gun to overtly higher recoil impulses is that unlike in, say, a G3 rifle where there are large locking recesses to allow to be "peened", in an MG42 barrel extension the vastly smaller surface area and more pronounced level of heat-treat metallurgy on the barrel extension results simply in it cracking at the locus of stress convergences. They crack! That gets expensive as that is the single most expensive and most metalurgically precise part in the whole gun.

Best then not to immediately resort to the "get a bigger hammer" thought process with these guns.....they should function just fine with the intended recoil impulse, if all else is as it should be. If it seems to need more recoil impulse, that is telling you there is something else going on.


-TomH

[TimMcBride]

Now I may be wrong,BUT- the wiselite receiver was made longer as was the buffer tip.I believe this was so a full-length spring could be used with the converted bolt,which is longer,hence the usual home-biult shortened spring.I believe it was Gordie K that worked on this problem.Thus,is you are running these parts,the inside dimentions,lengthwise,will be off.It will affect bolt travel and where the ejector hits.I would check this out

yes the receiver is longer but the recoil bushing has a 1 inch extension on it. The Bolt hits the extension right at the end of the stroke, the bolt face is only slightly behind the ejection port cut. I will take a picture tomorow when I get back to the shop.

[TimMcBride]

Tim,

What is the length of your Barrel-Bearing (?). PLease give the measurement to the closest ._ _ _ "
Note: The Germans made two different length Barrel-Bearings......but with your gun being a Wiselite-M53-??...I am not sure if Wiselite incorporated the used Barrel-Bearing...or made something new.(?) The longer of the two would hold the cycling-pressure in the system a split-second longer. This would also raise the RPM slightly on a gun running the shorter Barrel-Bearing.

Regards, RichardS in MI
US Army, Retired
Blanksguy2001@chartermi.net

I'll get measurements tommorow

[TimMcBride]

Tom,,

Thanks for all the advice. I would like to make the gun run right, but understand in the end it will always be a bastard.

[TimMcBride]

If you can't find the nozzle size you want, just weld and redrill the hole in a nozzle that isn't what you want. The nozzle controls the amount of recoil. If the bolt doesn't hit the buffer hard enough, it doesn't eject correctly. Making the hole in the nozzle smaller forces the barrel rearward with more force and speed.

Lubricate the bolt rails and top cover parts with some light grease to reduce friction.

Check the recuperator for proper function. Make sure the barrel moves freely in the jacket. You've already questioned your own ammo. How does is run with fresh 8 mm ammo?

Recommended reading: HDv 216/6 and the MG42 Armorer's Repair Manual.

Thankyou sir

[drooling idiot]

Its tough to say without more info but look at replacing the extractor and spring. I've seen guns that ran 8mm but didn't like 7.62 change their minds with a new extractor combo to hold the 7.62 tighter. $.02

[TimMcBride]

You've already questioned your own ammo. How does is run with fresh 8 mm ammo?
.

Wow. I tried 200rds of Romanian today, it made a definite difference.

[TimMcBride]

http://www.youtube.com/watch?v=8E4qA50I4hI[/video]

Alight. 8mm works. Now time to fight with 7.62

[42rocker]

OMG
You sure got that one running right and left and anyway but loose..... Don't over heat the barrel. The Germans went for a barrel change ever 150 FA rounds.

GLAD to see it running so well. Remember your statement about it always running so so. Well looks like it's running great. Way to go....

Later 42rocker

[JBaum]

You've already questioned your own ammo. How does is run with fresh 8 mm ammo?
.

Wow. I tried 200rds of Romanian today, it made a definite difference.

Glad you tried better ammo.... you wouldn't believe the abuse I get for suggesting it sometimes.

If your 42 changes the rate of fire while shooting, slowing down and speeding up, it's caused by poor ammo and you should quit shooting that ammo before something bad happens.

[TimMcBride]

Update:
Switched the gun to a German 11.5 booster, flash hider and barrel bearing; runs smoothly on yugo and Romanian.
Got 7.62 to run well. The issue was the top cover and feedtray were binding, fitted them and relieved a bit of the bottom of the feedtray so it sat lower. Gun ran without a hicup.
Thank-you to all on the site who offered help, it was invaluable to getting the gun to run right.