ejection issues - Updated page 2 with the problem solved

Post by **gunslingerdoc** » Mon Apr 03, 2006 3:18 pm

Well, I went out this afternoon after redo'ing some of my original parts - general cleanup stuff and I had to test some grip sticks for few other builds and new bolt.

Any way after a generous application of lube I got down to testing components - a few hitchs but easyly fixed. Ran thru 2 belts rapid fire, beautiful day, all was good!

And then, I began having empties hang up on the ejection port (at the front). I tried 4 different recoil springs (of differing lengths/strengths) and the heavier the spring the worse it got.

About every 4-6 rounds I would have a jam where the new round made it to the chamber but the empty hung up on the ejection port. Ive seen this before but not with such regularity.

Its not catching on the cocking handle (seen that one before and fixed it). Im using the same buffer (which I welded a 1/4 inch extension on to clear the FP extension and has sucessfully worked for a couple thousand rounds until today).

Any thoughts before I open up the ejection port?

Post by **drooling idiot** » Mon Apr 03, 2006 4:43 pm

rework the buffer to get rid of the 1/4" extension .

Post by **Pirate** » Mon Apr 03, 2006 6:19 pm

Doc, you have developed a problem like I am having. A few weeks ago several of us rented the range for the day. It was raining while
we were shooting. I ran several belts of yugo and romainian ammo with no problems. I took a break to eat
lunch and it started pouring and the gun got soaked and the receiver was full of water. when I started shooting it it started having the same
problem. At first I thought it was because the water and grease inside the gun had turned to sludge and
was causinf the problem. I cleaned the gun and took it out a few weeks later and had the same problem.
I changed the ejector spoon, the ejector, the bolt extension, bolt head, the recoil spring all to no avail.
basically the problen is the same as yours, it will either retain the case in the bolt face and it will jam the bolt
on the front of the ejection port or the case will stay inside the receiver and jam.
since we both changed all the parts in the ejection chain I think it may be a problem with the feed finger on
the top cover. that is what I plan on trying next time I take it to the range.

Post by **JBaum** » Mon Apr 03, 2006 6:43 pm

Considering that it worked for a few belts before having problems -

Do the semis use the bar inside the bolt to activate the ejector? If so, make sure it isn't bent.

Check the booster to make sure it's still working freely. If it's full of crud, it may be giving resistance to the recoiling of the barrel and bolt.

Unscrew the booster and stand the gun on its front end. Push down and make sure the barrel and booster move freely. Also check to see that the booster nozzle has the right sized hole for the cartridge you're shooting.

Post by **gordie k** » Tue Apr 04, 2006 10:35 am

i had the same prob. when i first built mine, what i found was the part in the bolt
that rides on the feed stun was worn and had to much clearance causing the
ejector spoon not to have enought movement, rember these parts are all
well used. what i did was to make a removible feed stud than i could turn that piece
180deg. that part was new fixed the prob. if you want pix i have some
gordie k

Post by **gunslingerdoc** » Tue Apr 04, 2006 2:29 pm

Ive swaped everything out except the feed mech parts. But these are all from a NOS mg3 top cover so Im doubting its a parts wear issue there (I had thought that might be the problem.

I'll have to check and see if the feed stud is binding any where. There is no easy way to make it pivot since the FP ext goes thru it - unless I make a 2 piece part.

The gun was clean when I started - Ive had it WAY MORE dirty and it still worked. I did check though and the barrel moves fine. Im thinking I have something binding and the bolts being slowed enough that the timing is off of the feed/ejection cycle.

Post by **gearlogo** » Tue Apr 04, 2006 11:19 pm

make a small post and then clip a small sealed bearing to it. It will spin and not wear.

Post by **gunslingerdoc** » Wed Apr 05, 2006 10:49 am

Maybe I should try adding a bit of metal to the rear of the ejector? I checked everything out last night and made sure everything was running smooth. I had a few parts that were binding in few spots, especially with the new made stuff. I also redid the half assed feed stud rat trap I was using on my first bolt extension by taking a new made one and intalling it.

I dont know if this helps any one else figure out the issue, but it gets worse the stronger the recoil spring.

Hopefully I'll get to test today.

I really want to get this thing going (again) so I can move on to a drum mag for my M/11 and some spade grips for the 42 - Im thinking it will look very cool on the AA 'pod with spades.!

Post by **Intruder196** » Wed Apr 05, 2006 11:12 pm

Keep us posted on what you find. Mine isnt doing that.....yet. So it helps to know where to start troubleshooting if/when it does.

Post by **gunslingerdoc** » Thu Apr 06, 2006 10:37 am

So far its a timing issue. I swapped buffers out stock vs. extended - no difference. If I use a smoother functioning bolt/ext, it happens less.

I also smoothed my rails a bit and that helped. I think I brake down and clean it and see if that helps - it didnt seem to help Pirate but may be it will have some impact on mine. I think I'll also open up the rails a bit or extend the ejection port forward.

Another issue may be my hammer - its getting a bit ragged and that may be another source slowing the bolts rearward travel as it trys to recock the hammer.

I think the bolts getting far enough back to partially strip a round but not far enough to clear the ejection port. At least this is my thought since the stronge the recoil spring the worse it gets.

DRH · Post by **DRH** » Fri Apr 07, 2006 12:22 am

Gunslingerdoc,
Here is what the spades looks like on the AA pod. I still need to get some nice bolts for the grips.

robertmcw · Post by **robertmcw** » Fri Apr 07, 2006 8:10 am

Emory over at crankfire systems could sure put a crankfire like the ones he does for the 1919s on that!!! They fire six times per revolution of the crank and allow the browning to run at near full auto speeds.

http://www.crankfiresystems.com/Spadegr ... nkfire.htm

fal lover · Post by **fal lover** » Fri Apr 07, 2006 11:09 am

hey drh that is super looking ,very nice workmanship, FAL

DRH · Post by **DRH** » Fri Apr 07, 2006 1:21 pm

I wish I could have a crank fire, but I can't. As a prisoner of Kalifornia, we are not allowed to have such fun. In the pictures you can see that the flash hider and pistol grip are gone. It is now a PC weapon, LOL.

robertmcw · Post by **robertmcw** » Fri Apr 07, 2006 1:35 pm

So, is it also a single shot weapon? Seriously I really feel sorry for you guys out there. Here in Texas we have no such silly restrictions to protect us from ourselves as yet but the bad news is that they are still trying.

Post by **Blanksguy** » Fri Apr 07, 2006 5:22 pm

Ejection "issues".......

MG42.....semi-only......
Just a couple of "ideas" on areas that could be possible problems areas........

1: I read in one reply..."it gets worse with a stiffer recoil-srping"......and "better if I substitute a slicker-bolt-assembly".
If the ejector-rod is good, and the buffer-tip has not been modified for length...............then this sounds like either not enought "reward-thrust" to the recoiling parts.....or something binding and/or not lubricated enough. You can check the binding with the gun clean.....and just the parts in the gun (minus the recoil-spring).....use blank-marker on possible offending areas/parts.

The "not enough "reward-thrust"...check the length of your barrel-bearing (IE: 1.970"=more reward-thrust....... and 1.865"=less reward-thrust). You might also check what size hole is in your Booster-Cup/"Nozzle" (IE: smaller hole=more reward-thrust...and larger hole=less reward-thrust).

2: Has anyone thought about "timing" of when the excess pressure inside the Booster-Cup/"Nozzle" is dumped out to the sides of the Flash-Hider? Because we have welded these SA42 receivers together at different points/different OAL.......the position of the barrel-bearing may be different on some SA42s that we have made. It may be possible to effect a change in this timing by either changing out to a different length barrel-bearing......and/or changing the height of the Booster-Cup/"Nozzle" at the rear openings which would effect a later dumping of the presure...and may cure some of the problems that are being discribed as "Ejector-Issues" ??

Just questions and comments at this point.
Let us know what you find out, RichardS.
Blanksguy2001@chartermi.net

Post by **gunslingerdoc** » Mon Apr 10, 2006 2:29 pm

DRH,

Looks too cool. I have to get the damn thing running again before I can get on to the spades.

Blanks,

This is the first SA 42 I built - right as Pirate was doing his. It used to run fine. Im using the correct 308 parts and the same ammo as before (I buy in LARGE amounts once or twice a year).

I'll check the barrel bearing - Ive never swapped it out. The ejector rod and bar are new.

Im gunna pull out the recuperator and check that out - ARGH. I hate messing with that damn thing.

Now my buffer tip is 1/8 inch longer (I actually measured it), so that could be an issue. But then 'WHy now?' since it worked before....at least for a few thousand rounds.

Ive swapped a few things around and replaced some parts so we'll see next trip to the range.

Hard part is not messing with lots of things at once so I can figure out the true problem.

Post by **drooling idiot** » Mon Apr 10, 2006 5:06 pm

hows the extractor on the underside of the bolt head look?
is the spring and plunger binding on the extractor ?
i remember tom r had a bound spring that held the extractor from moving freely.

maybe the problems not the ejector its the extractor ?

Post by **gunslingerdoc** » Wed Apr 12, 2006 11:06 am

Its not the booster cup/extension. I tried my extended one and a WWII one. No difference in performance. I tried 3 different 308 top covers from NOS to used, from all german new parts to mismash - no diffence.

I swapped bolt heads and all there parts - from new to used - zippo, no improvement.

The extended ejector made no difference.

I THINK its the charging handle. Its not held firmly against the inside of the receiver and can flop around. Mind you the empties arent catching on it (I had this problem when I first built the gun and fixed it).

What I found was that when I put a little lateral tension on the charging handle to keep it against the receiver, the failure to eject with the casing impacting on the ejection opening went away. I checked the charging handle and it flops around quite a bit so Ive have a new modified one I need to try. The slop must be enough to slow the bolt or otherwise mess up timing enough that the casing cant get out fast enough.

I'll report back after another range trip in the next few days.......

Post by **gunslingerdoc** » Wed Apr 12, 2006 2:01 pm

The charging handle being loose was the problem - the replacement fixed it. I then changed out the spring in my original charging handle and the gun ran fine.

Its still really weird to think that the charging handle was the problem even though the cases werent getting stuck on it but the front of the ejection port.

www.MG42.us

ejection issues - Updated page 2 with the problem solved

ejection issues - Updated page 2 with the problem solved

42

Spades

Kalifornia