We are currently hardening OOW receivers

[Independence Arms]

Hello, this is Randy @ Independence Arms.

We are currently hardening OOW receivers to the Bulgy receiver hardness of 32-36 HRC hardness. No warpage.

The cost is just $25.00 plus $5.00 shipping.

If you have a number of them, I can discount.

This is a good idea, so let me know.

We are currently accepting Polish rifle kit builds.
Let me know how we can help.

Randy

[grlenh]

An AKM newbie here.

Why would I want/need to do this?

Randy, what's your charge for an AK assemble using a Polish parts kit?

Thanks!

Glenn R.

[Independence Arms]

Indy Arms charges $225.00 for the underfolder barreled receiver (3 big holes drilled in receiver side).

This is the front/rear underfolder trunion installed with trigger gaurd and barrel installed.

Rivets are $25.00 per rifle.

Randy

All NFA rules and 922(r) rules apply.

[recon]

I can think of 2 other receivers that we could use but don't need hardening or do they? Firing line and Vulcan/Hesse receivers? Also which is best stamped or milled?

[Independence Arms]

Are far as the Firing Line receiver, call them and ask about it.
The Bulgarian milled receivers are definitely hardened.

I talked to Rob Hesse about his HK receivers, and he said they were stamped from 1050.
Possibly the ak receiver is also and could then benefit from heatreating.

Randy

[Reichpapers]

Not to play the devil's advocate, but how does all this sit with pray & spray's comment from the "Build It Yourself" forum?

((I'm curious why some people specify that they want the receiver fully hardened ?

Spot hardening is the method used on Bulgarian stamped '74 receivers and at least some EG receivers.

Spot hardening is much more problem free to build on at home. Read the reports of fully hardened Hesse receivers cracking at the corners. It is much more difficult to get proper riveting at home on a hardened receiver. Just a bit loose and the rivets will be cut by the hardened receiver, a touch too tight and the hole will be stressed and subject to cracks.

Spot hardening receivers will be cheaper and more dimensionally accurate. It is very difficult to totally harden stamped sheet metal and maintain close tolerances.

A properly spot hardened receiver will most likely outlast a fully hardened one, and the parts installed on it will take less of a beating too.

Uniform hardening is a poor idea on a metal stamping with tight radius bends, small diameter axis pin holes & subject to pretty severe impact stresses and vibrations. Uniform hardening can work acceptably, but is inferior in an AK receiver application to a proper spot hardening profile on a suitable alloy receiver.

There have been a few threads lately, mostly on the subject of OOW receivers, that contain info that is incorrect and opinions that are unsupported. Some of the hardening info posted is specific to OOW receivers and the 1050 alloy used to make them. I certainly would prefer any new model receivers to be made of 4130, correctly spot hardened by a precision process like inductive heating.

If someone has well supported reasons to prefer a uniformly hardened receiver, they would be very useful to know. Cut and pastes of second hand, out of context quotes that contain obvious errors doesn't sound like good information to make purchase decisions on.

s & p))

[Reichpapers]

Also, are the four small rear trunion rivets for the underfolder the same size as the front tunion rivets?

[Bossman]

Being a knifemaker who does his own heat treats and an AK nut who dreams of building his own AKM from a kit,I`ve been following the saga of OOW recievers for a while now,as I understand it the OOW recievers are induction hardened at the pin holes,the rest of the reciever being left in the annealed or soft state.
It appears that independance arms is offering a HT service for the recievers at an incredibly low price,the 32-36rc value seems to be ideal for the toughness the reciever needs.
-BUT-
Has anyone seen or heard of a kit that was properly built on an OOW reciever that failed because the reciever was not hardened?I`m not trying to start a flame or knock independance arms,but I cant recall reading a post about someones rifle going FUBAR because the reciever was soft,the only concerns I would have are if the rifle were run over by a truck or something,the annealed steel would not have the springiness to flex back into shape,it would mush and stay mushed.
That being said,even if no-one has had problems with the OOW recievers,I would still send mine to independance for treat just because after I spent the big bread on the kit,assemblage and reciever why not spend $30 to know it has the same hardness value of the eastern European recievers?
Bossman