Gunco Forums banner

Yugo M85 No rivets.

3K views 17 replies 11 participants last post by  2ndAmendican 
#1 ·
Built this Yugo M85 223 a few weeks ago. Just didn't like the looks of rivets,
so fired up my mig welder. After grinding and filing, I came up with this.
Ran about 150 rounds through it, and everything was quite good.
 
#2 ·
Has a nice clean look.
This approach can simplify a virgin build.
I see nothing wrong with this method.

Did you also do some interior trunnion welding?
Krinks like this can be brutal.
I riveted mine, and also did interior welding.
 
#4 ·
Not to get into another debate. It looks nice. Its your gun. I wont do it that way.

IMO I dont weld on trunions . Any weld requardless of how small can afect the temper of that area an create a stress riser. Stress risesr can lead to cracks an failure. im sure I simply dont do it others do. parts of the the trunion see about 9000 ft pounds of bolt thrust. It was an expensive kit. Im sure its not worth as much now. Again no slam your gun.

Id love to see were you welded it did you take any pics. some of the areas aroud the rivet holes are really close to the lugs an also there are very thin area of the trunion. you trunion is bulged so its not as bad as a akm trunion.

now if obama gets elected I might be weding every thing in site if guns need to be owned before a certain date etc.

Im a little nervious about my milled kits not being good for anyhting if there is a law change.
 
#5 ·
That does look slick without the rivets. I see a lot of people welding on trunnions and probably don't have any problems with it. Like 1biggun I wouldn't do it. It would be my luck that I would have the one that would blow up like a hand grenade!
 
#6 ·
I'm a rivet guy... me likey rivets :) Others have welded the rivet heads (I think that's what you mean?) with no issues, so I don't think there will be any long-term issues with that. It is .223 after all!

If I'm understanding correctly then internally the rivet is still doing its job... you just gave it a different head. It's .223 so I doubt there will be much stress vs. a .30 cal. Should be fine. If not you can easily re-repair it with another weld!
 
#7 ·
Nice job JT

I like it ... I too would be interested in where /how the welds were done like pookie ?? asked . I also would like to see if any ill effects happen after a few thousand rnds through it .... My HO ...it may even be stronger than rivots if welded correctly... although demilling could be an issue if canges are needed ?? Where or which head space gauges did you use ?>might be looking for a set ?
ak9
 
#9 ·
It's .223 so I doubt there will be much stress vs. a .30 cal. Should be fine
HMMM WELL I DONT HAVE THE BOLT THRUST NUMBERS BUT A 223 RUNS AT HIGHER PRESSURE THAN A 7.62

Others have welded the rivet heads (I think that's what you mean?) with no issues,
IF I WERE GOING TO DO A SCREW BUILD I WOULD WELD THE RECIVER TO THE RIVET PIECES LEFT IN THE RECIVER AN TRY NO TO HEAT UP THE TRUNION. YOU WOULD NOT BE WELDING THE RECIVER YOU WOULD BE TECHNIALY WELDING THE RIVET SHANK TO THE RECIVER.


...it may even be stronger than rivots if welded correctly...

PLEASE EXPALIN HOW DOING MULTIPL WELDS IN MULTUTIPUL PLACES IS GOING TO MAKE A HARDENED TRUNION STRONGER?? ITS NOT THE CONNECTION TO THE RECIVER THATS GOING TO GET YOU HURT ITS THE TRUNION FAILING THAT WILL GET YOU HURT . THERE IS ABOUT 9000 psi IF THRUST TRYING TO SEND THAT BOLT BACK AT YOU. BEFORE DECIDING ON A WELD BUILD RELIAZE THE FORCE THAT SENDS THAT BULLET UP TO 3500 FPS ( 223) IS ALSO TRYING TO FORCE THE BOLT BACK WITH THE SAME FORCE. YOU HAD BETTER BE CONFIDENT IN YOUR WELDING SKILLS. I HAVE SEEN A FEW GUNS POSTED HERE ANB ELSE WERE THAT LOOKED LIKE A CHICKEN SHIT THE PARTS TOGETHER AN TO MAKE IT WORSE GUYS WELDED ALL OVER THE TRUNION THINKING THEY WERE MAKING IT STRONGER. IF IT FAILS IT WILL NOT BE PRETTY.

WERE THE RIVET HOLES ARE, IS LOCATED DIRECTLY IN BETWEEN THE BARREL AN THE THE LUGS. IN ADDITION THE AREA ON A STANDARD AKM IS VERY THIN. IMO A BAD PLACE TO WELD. THE AREA AROUND THE BARREL PIN IS THIN AS WELL AN A STANDARD AKM AN THE PIN SEES ABOUT THE SAME FORCE ON IT AS THE LUGS. THE OPS GUN IS A BULGED TRUNION AN IF YOU HAD TO WELD ONE THAT WOULD BE THE ONE TO WELD BUT YOUR STILL AFFECTING THE METAL YOUR WELDING TO.

THE CONECTION TO THE RECIVER IS THE LEAST OF THINGS TO WORRY ABOUT . THERER IS ONLY ABOUT 5 POUNDS OF THRUST ON THE RVIETS, SCREWS OR WELDS. IF A WELD FAILS AND THE RECIVER COMES LOOSE ITS NOT LIKELY GOING TO HURT YOU. IF A TRUNION BREAKS YOU MIGHT BE KILLED.

ID LOVE TO TRY A BUILD WITH SOME OF THAT HIGH TEC SPACE AGE ADHESIVE THEY USE. CAR MAKERS USE IT AN PEOPLE SAY THE METAL WILL TEAR BEFORE THE BOND.

IF YOU WANT A SMOOTH LOOK A FLUSH AIR CRAFT STYLE RIVET MIGHT BE DOABLE IF THE TRUNION HOLES AN THE RECIVER WERE DEMPLED AN COUNTER SUNK TO CORISPOND. i CONSIDERED SUCH A BUILD ON A M70 WITH A THICK RECIVER AT ONE POINT. I HAVE NEVER TRIED IT . PARTS ARE TO EXPENSIVE THESE DAYS TO SCREW THEM UP.

THERE ARE SEVERAL OTHER THREADS WERE I GIVE MEASUREMENTS OF TRUNION THICKNESS WERE PEOPLE HAVE WELDED. A IMPROPER WELD ON HARDEND STEEL CAN BE JUST LIKE A ROCK CHIP IN A PIECE OF GLASS IT MAY NEVER BREAK OR IT MIGHT UNEXPECTEDLY SHATTER. IMO WEDEING ON A AREA IN BETWEEN THE BARREL PIN AN THE BOLT LUGS IS ABAD IDEA AN ILL STICK BY THAT OPINION.

BOTTOM LINE IS THERE IS NO WAY A WELD IS GOING TO BE DONE ON A HARDENED STEEL PART AN THE METAL WERE THE METAL WAS TURNED INTO A MOLTON POOL IS NOT TO AFFECTED, AS IS THE METAL AJECENT TO IT. IT DOSENT MATTER HOW SMALL IT IS. THE AMOUNT OF AFFECT IT HAS AN IF ITS SAFE IS WHATS UP TO SPECULATION. THERE HAVE BEEN FAILURES OF WELD BUILDS . I CANT SHOW A TRUNION FAILURE HOWEVER.

I HAVE WELDED A LOT OF REAR TRUNIONS TO MAKE PISTOL TRUNIONS AN i HAVE SEEN PERFECT LOOKING SMALL WELDS LITTRALY FALL OF ON THE BENCH DUE TO LACK OF PENITRATION AN LIKELY LACK OF PREHEAT. ITS CAN BE TRICKY WELDING HARDENED STEEL WITH OUT GETTING ANY HEAT INTO THE PART. i BNOW PREHEAT REAR TRUNIONS WHEN IM WELDING ON THEM. IT IS ALSO WORTH POINTING OUT THAT A LOT OF WELD BUILD FAILURES ARE FROM THE REAR TRUNION SEPERATING FROM THE RECIVER AN THE PARTS COMING BACK AT THE SHOOTERS FACE. THERE USED TO BE MANUFACTURES WHO SOLD WELD BUILDS AN THEY HAD FAILURES.

ITS HIS GUN AN HIS FACE HIS DECISION. I HAVE BEEN DOWN THIS ROAD OF DISCUSSION BEFORE ILL STICK TO MINE.

NOW WHAT WPOULD BE A GOOD DISCUSSION IS IF OBAMA GETS ELECTED AN YOU NEED TO GET 10 GUNS ASSEMBELD FROM KITS INA DAY OR SO WHATS THE BEAT WAY TO SLAP THEM TOGETER TO GRAND FATHER THEM IN IF NEEDED?????????

I HAVE DECIDED IF I WERE IN THAT SITUATION I WOULD TIG THE RIVET SHANS TOT HE RECIVER WITH A SPOT WELD OR EVEN POSSABLY GLUE THEM TOGETHER. YOU CAN ALWAYS GO BACK AN FIX THEM. IM MORE THAN A LITTLE SCARED THAT MY MILLED KITS WILL NOIT GET DONE AS I WAN TO DO REPAIR PLATES. THERE IS NO FAST WAY TO MAKE IT A GUN IN A HURRY. ASDIE FROM MAYBE WELDING SHEET METAL TO THE SIDES OF THE STUBS AN DRILLING THE HOLES.
 
#10 ·
... I WOULD TIG THE RIVET SHANKS TO THE RECIVER
Hrm I thought that's what was done? Re-read the first post... I don't think the entire rivet holes are "empty" of rivets?. I think the rivet shanks are still there but the heads are welded to the receiver. Which honestly doesn't seem too bad as long as the rivet shanks are "good" and fill up the holes entirely.

I agree it wouldn't be a good idea to "only" weld the receiver to the trunion. The AK trunions aren't build to be welded on directly. I've repaired a trunion that was severely damaged by welding and I've had good luck with that, but fastening an AK trunion only by welding is something that I too would not try. The Germans do that on their HK rifles, but the trunion is different on those. And who can say how they are hardened differently around the roller locking areas. Maybe they aren't?

The issue as I see it would be that the hardened area around the locking lugs would lose their temper and unpredictable results would happen. Premature headspace issues thanks to softer metal in that area or worse. But this is speculation and assumes so much welding was done that the heat treat of the trunion is lost.
 
#12 ·
The issue as I see it would be that the hardened area around the locking lugs would lose their temper and unpredictable results would happen. Premature headspace issues thanks to softer metal in that area or worse. But this is speculation and assumes so much welding was done that the heat treat of the trunion is lost.
MY THOUGHTS EXACTLY. THE OP STATED ITS WELDED FRONT REAR AN SIDES SO ITS MORE THAN JUST WELDING TO RIVET SHANKS.

I HAD A TRUNION HERE FROM A BOTCHED BUILD THAT WAS WELDED EVER WERE THE RECIVER TOUCHED AN THE THING WAS SCARY TO LOOK AT.
 
#14 ·
Jimmy you been a busy boy..

i did a mini tut on welding in place of rivets a long long time ago...

its like anything else we do in this hobby.. good work is good work.. crappy work fails.

several thousand rounds down the pipe of my 74 weld combo build.. still fine.
 
#15 ·
It's good to know someone has the balls to try something new.
As this kit cost several hundred dollars, It was not my intent to
build something cheap, reather something different. It helps that
i'm a certified welder, and I do know, and understand metal.
 
#17 ·
I prefer rivets.. in the Ak build, but I don't think a welded Ak will just fail and kill ya.. The AK has two main locking lugs and unless your welding directly to the locking lugs I doubt your going to destroy the heat treatment.. There are other guns that are welded like the G3 it's sheet metal receiver is welded to the trunion in three places and they run 308. Also the (factory) yougo AK 762X39 non bulged trunion AKM has it's receiver spot welded to the trunion in addition to the rivets.. so ain't nothing new... B2B
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top