aK barrel

[zot]

received my AK receiver today, made in U.S.A.
marked KRINKS Naples FL. M-97 7.62x39 and
serial number is KRSxxxx, okay, measured inside diameter of barrel trunion and its
.900" to .901". my barrel measures .905" to
.907" I know this barrel isn't a drop in, its
a press fit. but how much metal should come off barrel to fit in, or should none be removed? I'll be using a hydraulic jack to
push the barrel in,but I sure don'twant to crack the trunion pushing a oversized barrel
in. any help?

 

[Badger Arms]

Try ice water and a torch to heat up the trunion. That might solve your problem. Heat up the trunion with a torch and cool the barrel in ice water after coating it with a heavy grease. They should slip together then. Make sure you have a quick way of making the barrel prependicular with the receiver before you start and go through a few dry runs first. You won't get a second chance. That little difference is likely just finish also. You COULD just sand it off the barrel and be good.

 

[zot]

I guess my question should be what is the
mil specs for barrel diameter?there has to be
a plus .002" or plus .004" oversize for press fit. but no one states a spec size.if I
try heating the trunion its a cast steel
part and any heat treatment would be lost
and I have removed all finish off barrel and inside trunion, also both parts seem to be more oval than round, high low spots. got to
buy MORE books. thanks for the idea

 

[cmore]

don't need to heat it too much, 250-300 degrees will do it. go to welding supply house or large industrial supply house and get temp-il-stik crayon. comes in several degree ranges . just mark piece and heat until mark melts - temp will be just right, and won't hurt heat treat if you don't get too hot.You could also just put the trunnion in boiling water for a few minutes, that shoud do it also. put the barrel in the deep freeze,( it will take an hour or so to cool) or get some dry ice and cool the end for at least 20 minutes before assembly. this should give you enough difference to hand assemble- no force,or not much, needed. when it gets back to room temp- it will be tight.

 

[zot]

Mr. Stringer? Mr.Keenan?

 

[George Stringer]

Zot, this is why I don't mess with press fitting these rifles. I've cracked 2 of them and that was enough. If it were me I would thread the receiver and the barrel to screw on and then add 2 pins for extra security. Even with just the .005" to .007" difference in diameter the threads would allow you to screw it in and keep the barrel aligned while drilling for the pins. If you don't have anyone near you to do this for you feel free to e-mail me. I've done it a few times. George

 

[zot]

thanks for all your info,George I don't know,
if it was a milled receiver I would have it
threaded,but.? this thread has gone as far as
it can ,I think?please lock it, thanks

 

[Steve Smith]

ZOT, how about also look at www.ak-47.net under the "build it yourself" forum.

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Frontsight!
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Why is everybody all boud up about the AK-47? YEAH, I GOT ONE, WHAT'S IT TO YA?!