Gunco Forums banner

1 - 7 of 7 Posts

·
Registered
Joined
·
22 Posts
Discussion Starter · #1 ·
I have access to a heat treating oven and was wondering if there were any problems with heat treating the entire receiver?
 

·
Registered
Joined
·
4,077 Posts
some guys have mentioned it getting brittel , something to keep in mind. relax it some after it is hardened.
 

·
Registered
Joined
·
1,151 Posts
I would think one could get around the warpage issue by heating the entire piece to about half of the heat required, then heating the critical spots the rest of the way. This should reduce the temperature difference enough so warpage isn't a problem.
I don't think I'd treat the whole receiver though, as Hotbarrel says it'd get very hard and would probably be brittle. What we want is a (relatively) soft receiver so it has some give to flex with recoil, but with a couple of really hard spots to resist wear on the axis pins. There really isn't all that much force imparted to the reciever on the AK-most of the force is taken by the front trunnion, the rest is just the bolt slamming back and forth which is really not that severe, especially in semi only guns like we are building.
I think the old B-West assembled chinese AK's had wear problems because the receivers were made from the wrong materials (we've gotten around that now, I think 99% of receivers are being fabricated from 4130 steel now) and were not heat treated around the axis pin holes.
 

·
Gunco Irregular
Joined
·
4,323 Posts
I agree with Hotbarrel and Cammobunker. Differential heat treating gives you the best of both worlds - strength and wear resistance around the axis pins(hard) and shock absorbing through out the rest of the receiver(spring temper). If you do decide to treat the entire receiver make sure you do temper it back so it is not brittle. You might also want to stress relieve it before you start as this will help reduce the chances of warpage by relieving the stress that results from the bending. You will probably be able to use your oven for that, bring it up to non magnetic heat and then let it cool to room temperature very slowly by rurning off the oven and leaving it in till it is cool. I'm really not familiar with 4130 as far as heat treating but there should be penty of info on the web.
 

·
Registered
Joined
·
431 Posts
The Russians heat treated the entire receiver. To keep it from being to brittle you have to aneal it, heat it at a low temp for a short period of time. If you aneal it correctly it will retain most of it's "hardness" but not be as brittle.
 

·
Gunco Irregular
Joined
·
4,323 Posts
3/325 said:
The Russians heat treated the entire receiver. To keep it from being to brittle you have to aneal it, heat it at a low temp for a short period of time. If you aneal it correctly it will retain most of it's "hardness" but not be as brittle.
Annealing is to remove all hardness, like the stress release I posted about above. What you mean is to temper or draw back some of the hardness in the receiver, and that works fine for the russians because differential heat treating would be a pain in the a$$ in a production setting but it is not better. Even if you just harden the axis holes you should still temper them. There is plenty of good info on the web for heat treating and tempering.
 

·
Registered
Joined
·
22 Posts
Discussion Starter · #7 ·
Thanks for all of the answers, was really informative. Was mostly curious if there was any advantage to doing the whole receiver. Tomorrow I start reading a book on heat treating, lent to me by a former gunsmith I work with. Unfortunately he knows nothing about the AK.
 
1 - 7 of 7 Posts
Top