Thread: .30-06 stretch AR

Retrieved: December 08, 2013

Just a thought experiment here...

I've always liked the AR-10. Being cheap I'll probably never buy one, but I could build one... sort of. It wouldn't have to be a real AR-10, just an AR- pattern rifle in .308. For that matter, why not .30-06?

Milling an AR receiver from billet has been done often enough. I've found several sets of drawings on the 'net.

As a first approximation, just stretch an ordinary AR at the magwell, widen enough to take an FN-D .30-06 mag, do any other fiddles needed. Use an ordinary AR trigger group, stock, pistol grip, etc.

That leaves the question of an upper. The AR uses a 1919-style barrel extension and a multipiece bolt, which wouldn't be all that difficult to upscale to suit the larger cartridge. The barrel extension and bolt head could be broached in the lathe, using the carriage or a tailstock fixture. Practically everything in the upper would have to be handmade.

Probably not worth the effort, but an '06 would be way cool.

TRX
04-02-2010

You guys aren't helping. You're supposed to say, "Why would you want to do that?" or start a .308-vs.-.30-06 argument. Or at the very least, "what, you didn't know that's been done before, and you can buy the parts cheap?"

[486]
04-02-2010

Originally Posted by TRX
"what, you didn't know that's been done before, and you can buy the parts cheap?"

It HAS been done before, but good luck getting parts. It was some sort of 40th anniversary limited 1 of 100 deal. Saw one at a gunshow for $3.5K... I'd just go .308, no real benefit to going -06 besides heavy bullet loadings...

TRX
04-02-2010

I found some, too. Apparently a couple of places make/made AR10 variants in .30-06. There's some discussion in this thread:

http://www.cncguns.com/forum/index.php?topic=273.0

Cobb seems to have been the major player, though its web site is 404 now. Someone said they got bought out by Bushmaster. I found a picture. They also offered .300 Win Mag and .338 Lapua.

There's another thread here:

http://www.thehighroad.org/showthread.php?t=240563

and here:

http://www.thefirearmsforum.com/showthread.php?t=61577

jreifsch80
07-09-2010

ahhhh they had them in 8x57 too!? lol my neighbor has been drilling AR's into my mind so i've been tempted to build one how with those screw together lower prints it would be simple to stretch the magwell to fit fn d 8mm mags, i've been wondering if a guy could just stretch an ar .308 bolt and carrier or if new ones would have to be made

Viper Dude
07-09-2010

A real retro 30'06 variant of the AR-10 is the WW-II Johnson rifle.

Mad-Machinist
07-09-2010

The lower isn't the problem....it and the upper can be streched....the tricky part is gonna be the legnthened bolt carrier......

[486]
07-09-2010

Originally Posted by Viper Dude
A real retro 30'06 variant of the AR-10 is the WW-II Johnson rifle.

Or the very first prototype AR-10.

You might not even have to lengthen the upper, or the bolt carrier. You might be able to stuff it into an AR10 by reconfiguring the FCG, shortening the buffer [to lengthen bolt travel], and moving the mag well back. Maybe delete the BHO to make room too.

moleman
07-09-2010

For a bolt, partial carrier and barrel I'd explore a remington 74, 7400, 742 ect series rifle. The carrier would have to be modified with a tail extension and something for a piston to push against. I wouldn't make it direct impingment. The barrel already has the lugs in it like an ar15 barrel, and the bolt is already set up for hammer fired. On second thought it might be faster to adapt an 870/1100/11-87 pistol grip stock to a 7400, then mod it for the high cap mags. I've seen 742 demilled guns on gb go for cheap.

jreifsch80
07-10-2010

Well I think a guy could maybe squeek out a little more magwell room by moving the magwell front a little more forward but keeping the front pin hole where it originally is, might not be able to hinge it forward though. Would it be possible to get away with a standard ar10 lentgth carrier and at worst lengthening the bolt tail and firing pin? If that would be workable I'm sure a guy could make a lengthened welded steel tube upper with no forward assist and a right side fixed charging handle to keep it simple. Now here's a curve ball, how crazy hard would it be (if even possible) to build a 7.62x54r ar haha

jreifsch80
07-15-2010

i did some fiddling around with photo shop (i am crappy at it so don't be too mean haha) anyway i lengthened the magwell and added another idea i had for a scratch built lower, grafting on an mg42 grip. i think they look so cool. anyway my idea is a 24 inch 8x57 barrel with a normal ar10 length upper and maybe a shorter buffer so the bolt and carrier can move a little farther back (as mentioned earlier) and fn d 8mm bar mags (in my cheesy picture i just lengthened the .308 mag) also i just pasted on a russian scope since i couldn't find a good picture of a zrak. behold i call it the ar-76 haha if it seems like it actually might be possible then i'd actually like to build something like it.