Why don't people use AR receivers for non AR projects?

[Mosinguy]

Maybe I'm not looking in the right spots, but why haven't any home builders used an AR lower as the base of a non-AR platform rifle? Sure it's much easier to make your own upper out of existing materials and mating it to the lower, but why not create an entirely new gun out of the AR receiver? I think it would be a fun challenge and much more entertaining (IMHO) than just throwing parts together and getting a rifle that everyone and their brother seems to own.

 

[CountryBoy19]

There are some out there... there is a belt-fed upper that goes on AR/M16 lowers that isn't at all like an AR upper, there is also a single-shot 50 BMG upper that mates to an AR lower, and you can get cross-bow uppers that go on AR lowers...

It's a "versatile platform" but sometimes its just easier to stick with the way it was designed and build an AR upper for your empty lowers. Although for custom jobs AR lowers are a great starting point for FCG, stock, etc if you're really into building a brand new upper design from scratch.

 

[hrearden]

I kinda wondered this myself. There are also some pistol/carbine builds in pistol calibers in books floating around. They build from tubes and round stock, much like Stens.

 

[Mosinguy]

I've been wanting to build a rifle and maybe this will be a future project...

 

[hrearden]

A tube , a nice barrel, some round stock, and proficiency with a lathe would get you started.

 

[warthog]

Well, an AR is assembled, not built. I assembled a .45 cal and a 9 mm carbine on a couple of AR receivers. The 9mm is something done pretty regularly but the .45 took some machining to make work and I would call that a build.

You can buy barrel blanks rather than trying to rifle a piece of rod, which isn't as easy at it sounds. I used a barrel blank and a lathe to make the barrel fit the upper properly, the upper of course needed some machining as well. Then there was the magazine well, I chose to use grease gun mags as at the time they were plentiful and cheap. It took a while and I made it as a straight blow back design but it eventually worked out. I believe Will Heyden has also done this and for a while, before his fame, had done a small run of lower receivers ready for a .45 assembly too.

Not everyone just take these and goes plain vanilla. I have since sold both carbines though if the guys still have them can try for some pix of they're willing.

 

[wsenefeld]

PSE makes a nice crossbow upper that goes on an AR lower, but costs more than most AR uppers.