M14 80% receiver options

[nick]

So, I'm getting a Polytech M14 kit off Gunbroker, despite the interference of one very annoying gentleman. I want to go down the 80% route. I see the rear stubs for sale on Gunbroker, and I'm not sure how good the front stub in that kit is (see the pictures). Still, I'd need to fill the gap between the front and rear stubs somehow. Does anyone make repair sections? I believe, I also saw unfinished castings for sale, but I'm not sure, if that route is better. So, what are the options out there, other than buying a 100% receiver. If I wanted that, I'd just buy the rifle. It would probably be cheaper, too, but not nearly as much fun

[tr6guns]

You might pick up a few of these and see if you can salvage enough to make one complete..

http://www.fulton-armory.com/m14-receiver-half-usgi-government-demilled-various-manufacturers.aspx

[Grumpyoldretiredcop]

Be careful. There are a number of ways that you can run afoul of Federal law in the process of rewelding an M14 receiver to say nothing of the metallurgical issues. You may find this M14 Forum thread educational. I'm assuming that the cut receiver portion you show is Polytech, not GI.

From post #45 in the referenced M14 Forum thread:

"According to Jerry Kuhnhausen's "The US .30 Caliber Gas Operated Service Rifles- A Shop Manual Volumes I&II", page 231:
"The US m14 Rifle, is defined in section 5845 (b), Chapter 53, Title 26 U.S.C. AS A MACHINE GUN....Section 5845 (b) further defines M14 rifle components as follows: the term (machine gun) shal also include the frame or receiver of any such weapon, any part designed and intended soley and exclusively, or combination of parts designed and intended, for use in converting a weapon into a machinegun, and any combination of parts from which a machine gun can be assembled if such parts are in the possession of or under the control of a person. This definition also includes U.S. M14 Rifles that have had the select fire componants removed or have been converted into semi automatic function (Match versions for example) that have the select-fire components welded, ground, or otherwise rendered nonfunctional".

Plainly put, the M14 is specifically named as "once a machine gun, always a machine gun". The reason we can get away with using M14 parts on an M1A or an M-14 (note the dash), is that they are no longer "solely intended" for use on an M14 (notice no dash).

Rewelds are a no no."

If you can find an 80% receiver, the above obviously does not apply unless one were silly enough to finish the receiver in such a manner that it could be assembled in a full-auto configuration. You'd need to know something about heat-treating or have someone who does in order to finish one. I've seen them on occasion, but they're not common.

[nick]

Be careful. There are a number of ways that you can run afoul of Federal law in the process of rewelding an M14 receiver as well as metallurgical problems. You may find this M14 Forum thread educational given the photo of the saw cut receiver that you have posted.

Thanks, checking out the forum. However, it's not a saw-cut M14 receiver. It's a front stub (the rest of the receiver is missing) of a receiver that was semiauto to begin with (it's a Polytech M14, not a USGI one).

[nick]

It does sound like it's a good idea to write to the ATF before buying the rear stub, ridiculous as it may be. Either that, or look for those castings. Any other options?

[kcstott]

As to the reweld issue AK's are in the same ball park and are re welded too.

the thing is you must have a properly demilled receiver first then weld up the areas that made it a machine gun then reweld to a usable receiver

[nick]

As to the reweld issue AK's are in the same ball park and are re welded too.

the thing is you must have a properly demilled receiver first then weld up the areas that made it a machine gun then reweld to a usable receiver

From what I'm reading, ATF has special love reserved for M14, kinda like CA DOJ and SKS.

The question I have, provided ATF is ok with the way I'm thinking of doing the reweld (M14 rear stub and Polytech front stub, with some filler in-between) is where to get the filler. Looking at the rear stubs available online, I'll need a lot of that filler, about 3" worth at least. Kinda like the repair plates I saw for milled AKs.

[ar15barrels]

However, it's not a saw-cut M14 receiver.
It's a front stub (the rest of the receiver is missing) of a receiver that was semiauto to begin with (it's a Polytech M14, not a USGI one).

Right, but if you were yo weld YOUR polyech receiver stub to one of those M14 cut receivers to make a complete receiver, you will have made an M14 because the markings are on the rear half and your receiver will SAY M14 on it as well is having the full auto cuts.
So, you would be rebuilding an auto receiver in the eyes of the batfe.

The fact that you used the front ring from the stub of the polytech semi-auto receiver that your parts kit included won't matter because the front area of the receiver has nothing to do with it being semi-auto or full-auto.

[nick]

Right, but if you were yo weld YOUR polyech receiver stub to one of those M14 cut receivers to make a complete receiver, you will have made an M14 because the markings are on the rear half and your receiver will SAY M14 on it as well is having the full auto cuts.
So, you would be rebuilding an auto receiver in the eyes of the batfe.

The fact that you used the front ring from the stub of the polytech semi-auto receiver that your parts kit included won't matter because the front area of the receiver has nothing to do with it being semi-auto or full-auto.

Wouldn't the rear stub be properly demilled, since it's missing not only some sections, but the entire front half or 2/3, and if the full-auto stuff is removed before the reweld is attempted?

[ar15barrels]

Wouldn't the rear stub be properly demilled, since it's missing not only some sections, but the entire front half or 2/3, and if the full-auto stuff is removed before the reweld is attempted?

The batfe says no.

[nick]

The batfe says no.

Joy. Going back to the idea of writing to them, just in case they may see things differently this time. Looked at the price of semiauto M14 receivers - around $1000.

Hmm, any way to adapt a Garand receiver to the job?

[ar15barrels]

Looked at the price of semiauto M14 receivers - around $1000.

The cheapest way to get an M1a/M14 type rifle is to buy an assembled one.
Did you think you could build one from parts cheaper?

[nick]

The cheapest way to get an M1a/M14 type rifle is to buy an assembled one.
Did you think you could build one from parts cheaper?

Nope, I specifically want to build it. I looked at the receivers out of curiosity.

[Grumpyoldretiredcop]

Thanks, checking out the forum. However, it's not a saw-cut M14 receiver. It's a front stub (the rest of the receiver is missing) of a receiver that was semiauto to begin with (it's a Polytech M14, not a USGI one).

As I suspected since the Polytech barrel is screwed into it (the thread on Polytech barrels is different) and noted early in my post. As long as you find the back half of a non-M14 receiver to weld on, you'd be good absent any metallurgic issues. Or you could try your luck with getting a letter from BATFE and using the back half of a M14 receiver, deleting the full-auto features, but by my understanding, no such letter has been issued for years. With that one, you might run into metallurgic problems as the two parts of the receiver would be different alloys (not an expert on the subject, so maybe not).

You might want to have a chat with Tim Shufflin of Shuff's Parkerizing; he machines Garand receivers and FCGs to use M14 mags. Good luck with your project!

[kcstott]

Here's what's done with FAL's, AK's and the like.

If you have a properly demilled receiver stub you weld up the all the featurs that make it fullauto first, make it exactly like a M1A receiver in every mechanical detail. Then weld up the serial number and the markings that say U.S. Rifle M14 bla bla bla. then and only then weld the chunks together.


But here is a very good piece of advice Don't bother. Reason??

1. you are going to spend more time trying to get everything lined up and try to weld it that your chances of success are very slim at getting a safe, strong, straight, receiver.

2. It will need to be annealed and reheat treated and that is not good 8620 doesn't like to be cycled like that and if they only case hardened it well you run into other heat treat related issues as well. as you can fully anneal a carburized part and then subject it to further carburization later. the metal don't like that and you end up with to much carbon and to deep of a case

3. Safety. The M14 M1A is a strong action but re-welding it is not good not on a 55 Kpsi action. Not re-welding it in a location where the receiver has the least amount of strength and where the action is now fully relying on the quality of your weld and the filler you use. along with the proper heat treat to contain all the parts.

I'd machine one from solid before I would re-weld one.


Again as to the rewelding of a fullauto receiver please read the fourth paragraph down

ATF letter

Notice it says "you may use remnants from a properly destroyed receiver"