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9/22/2017 12:11:25 AM
Posted: 9/7/2010 8:49:21 PM EDT
Been thinking about this one for a while. Haven't done any engineering feasibility studies, prototyping, much research, or anything. Just kicking it around in the BHG.

Why, with upsized barrel, bolt, locking lugs, long upper and lower, and suitable magazines, could you not make an AR that would run big calibers? I don't mean .50 or .408, although that's not outside the realm of possibility. I mean .30-06, .300 Win Mag, .338 Lapua, or .458 Win Mag.

If it's possible, why hasn't anyone done it?

If someone's done it, why the hell don't I know about it?

Hell, if nothing else I think this would be a great way to win over more Fudds. There is a sizable portion of the population that would lap this up.
Link Posted: 9/7/2010 8:52:36 PM EDT
30-06 was available. I believe Bushmaster bought the company that was making them. There's no reason you can't, just not much market I'm guessing. Magazines might be a bitch for anything past 10 rounds.
Link Posted: 9/7/2010 8:53:37 PM EDT
I dunno... there's something about DI operation, and that much powder that makes me... uncomfortable...
Link Posted: 9/7/2010 8:54:43 PM EDT
Cobb made some 3006 and larger ARs.
Link Posted: 9/7/2010 8:57:45 PM EDT
[Last Edit: 9/7/2010 8:58:49 PM EDT by 70satvert]
Originally Posted By Mall-Ninja:
I dunno... there's something about DI operation, and that much powder that makes me... uncomfortable...


Would a piston upper make it more "safe?" Also, would something like the OP's idea be feasible on a .308 lower?

ETA: Proprietary mags would probably be necessary.
Link Posted: 9/7/2010 8:58:37 PM EDT
My guess is mainly interest. It get's cost prohibitive to shoot magnum calibers. Outside of people on this site, I don't know a lot of people buying AR10 variants for the same reason.
Link Posted: 9/7/2010 8:59:12 PM EDT

Originally Posted By Kuraki:
30-06 was available. I believe Bushmaster bought the company that was making them. There's no reason you can't, just not much market I'm guessing. Magazines might be a bitch for anything past 10 rounds.

How about BAR(USGI, not civilian model) mags for them?

I don't know how readily available those are any more though.
Link Posted: 9/7/2010 9:01:35 PM EDT
[Last Edit: 9/7/2010 9:03:32 PM EDT by OKZJ]

Originally Posted By 70satvert:
Originally Posted By Mall-Ninja:
I dunno... there's something about DI operation, and that much powder that makes me... uncomfortable...


Would a piston upper make it more "safe?" Also, would something like the OP's idea be feasible on a .308 lower?

ETA: Proprietary mags would probably be necessary.

You could do piston, DI, whatever.

Also, I think you could make BAR mags work.

ETA: Read about Cobb. Looks like Bushmaster swallowed them up never to be seen again. That was a cool design. Too complicated and expensive, but cool.
Link Posted: 9/7/2010 9:08:49 PM EDT

Originally Posted By thelaw09:
My guess is mainly interest. It get's cost prohibitive to shoot magnum calibers. Outside of people on this site, I don't know a lot of people buying AR10 variants for the same reason.

Yeah but hell, look at the guys spending big bucks for the .338 bolt actions then another $2000 to accurize and customize. At the end of the day all you're left with is a bolt action rifle. Then to shoot them you still send at least a Washington downrange everytime you pull the trigger, even if you're reloading. If I had the option of a quick follow up without operating a bolt I would damn sure take it.

If you're getting all paranoid worrying about slinging brass and giving up your super secret squirrel sniper hide, give the upper a side charge handle and toggle off the gas port with a little valve.
Link Posted: 9/7/2010 9:30:51 PM EDT
Cobb made a 30-06. The .308 platforms can also shoot a .338, .243, and .260 Remington. I'm holding out to actually see some data on the .30 AR because it is supposed to get .308 performance out of a .223 sized reciever.
Link Posted: 9/7/2010 9:34:31 PM EDT
[Last Edit: 9/7/2010 9:37:28 PM EDT by ShootToKill]
Too much $ for the rifle IMO. I reload for my .338lm and still cringe at the thought of funding ammo for a semi in that caliber.
.338 Lapua Magnum AR

Only 13lbs! . Probably upwards of 17-19lbs one you put everything on it... If money were no object I would have one of these. Suppress the thing or get a good break and you could really do some serious damage with that thing.
Link Posted: 9/7/2010 9:43:12 PM EDT

Originally Posted By ShootToKill:
Too much $ for the rifle IMO. I reload for my .338lm and still cringe at the thought of funding ammo for a semi in that caliber.
.338 Lapua Magnum AR

Only 13lbs! . Probably upwards of 17-19lbs one you put everything on it... If money were no object I would have one of these. Suppress the thing or get a good break and you could really do some serious damage with that thing.

OK, see, now we're talking. Take something like that but for .270/.280/.30-06/.300 Win and work to bring it in at a price point somewhere around $1200. The biggest pain in the ass is going to be getting barrels made.


Link Posted: 9/7/2010 9:47:00 PM EDT
Originally Posted By OKZJ:

Originally Posted By thelaw09:
My guess is mainly interest. It get's cost prohibitive to shoot magnum calibers. Outside of people on this site, I don't know a lot of people buying AR10 variants for the same reason.

Yeah but hell, look at the guys spending big bucks for the .338 bolt actions then another $2000 to accurize and customize. At the end of the day all you're left with is a bolt action rifle. Then to shoot them you still send at least a Washington downrange everytime you pull the trigger, even if you're reloading. If I had the option of a quick follow up without operating a bolt I would damn sure take it.

If you're getting all paranoid worrying about slinging brass and giving up your super secret squirrel sniper hide, give the upper a side charge handle and toggle off the gas port with a little valve.


This is a a little off your topic. With your example of 338lm, the round's main advantages are long range and accuracy. I'd rather have a bolt action rifle firing it for the accuracy advantage over a semi (even if only perceived) because too quick/ too many follow up shots negates the 338's advantage. I'm also a self admitted cheap skate who rarely even fires a full 30 round mag of 223. I'd never be able to enjoy rapid firing a 338 even if I had millions in the bank.

Link Posted: 9/7/2010 9:57:34 PM EDT
Couple years back, somebody was making a lower with interchangeable mag wells for different length magazines. Attach the correct magwell for your chosen magazine and caliber, then attach upper, then you're GTG.

Posted Via AR15.Com Mobile
Link Posted: 9/8/2010 4:29:33 AM EDT
.30-06, .300 Win. Mag., .458 Win. Mag. etc. aren't magnum length cartridges...
Link Posted: 9/8/2010 4:40:49 AM EDT
Magazine function with belted rounds would probably be a nightmare.
Link Posted: 9/8/2010 3:15:15 PM EDT

Originally Posted By DoubleARon:
.30-06, .300 Win. Mag., .458 Win. Mag. etc. aren't magnum length cartridges...

No comeback for that one. OK. Replace "Magnum" with "Actual Long Action, not AR-10 vs AR-15 Long Action".
Link Posted: 9/8/2010 6:46:24 PM EDT
So you want an AR to handle standard length cartridges?
Link Posted: 9/8/2010 7:28:35 PM EDT

Originally Posted By DoubleARon:
So you want an AR to handle standard length cartridges?

Yeah. The AR-10 isn't long enough for .30-06, is it?
Link Posted: 9/8/2010 7:39:44 PM EDT
I've always wanted ARs in .45-70..........and 416 Rigby
Link Posted: 9/8/2010 7:46:41 PM EDT
I am all for more calibers, guns, etc. but i still want someone to make an AR in 22 hornet!
Link Posted: 9/8/2010 7:50:22 PM EDT
Originally Posted By vanilla_gorilla:
Couple years back, somebody was making a lower with interchangeable mag wells for different length magazines. Attach the correct magwell for your chosen magazine and caliber, then attach upper, then you're GTG.

Posted Via AR15.Com Mobile

MGI makes them Mack Gwinn playing mad scientist (or engineer in this case) again...cool concept when you pair it with the QCB upper.


Posted Via AR15.Com Mobile
Link Posted: 9/8/2010 8:01:14 PM EDT
[Last Edit: 9/8/2010 8:04:18 PM EDT by ArmyInfantryVet]
Why would you be interested in a .30-06 when .308 is only a couple hundred fps slower? It's not like .30-06 blows away the .308 in terms of performance.

Link Posted: 9/8/2010 8:08:04 PM EDT
Originally Posted By ArmyInfantryVet:
Why would you be interested in a .30-06 when .308 is only a couple hundred fps slower? It's not like .30-06 blows away the .308 in terms of performance.



im kinda interested in how a 7.62x54R AR platform would perform against a PSL or even a SVD...
Link Posted: 9/8/2010 8:12:54 PM EDT

Originally Posted By WarWeapon762:
Originally Posted By ArmyInfantryVet:
Why would you be interested in a .30-06 when .308 is only a couple hundred fps slower? It's not like .30-06 blows away the .308 in terms of performance.



im kinda interested in how a 7.62x54R AR platform would perform against a PSL or even a SVD...

consider that the PSL and SVD are 3-4 MOA guns, and the Stoner design allows for submoa. I would imagine pretty good.
Link Posted: 9/8/2010 8:20:36 PM EDT
Originally Posted By ShootToKill:
Too much $ for the rifle IMO. I reload for my .338lm and still cringe at the thought of funding ammo for a semi in that caliber.
.338 Lapua Magnum AR

Only 13lbs! . Probably upwards of 17-19lbs one you put everything on it... If money were no object I would have one of these. Suppress the thing or get a good break and you could really do some serious damage with that thing.


Make that bitch in an SBR and throw on a heavy-duty muzzle brake and are cooking with gas.

Link Posted: 9/8/2010 8:26:39 PM EDT
Originally Posted By Amontgomery:
Originally Posted By ShootToKill:
Too much $ for the rifle IMO. I reload for my .338lm and still cringe at the thought of funding ammo for a semi in that caliber.
.338 Lapua Magnum AR

Only 13lbs! . Probably upwards of 17-19lbs one you put everything on it... If money were no object I would have one of these. Suppress the thing or get a good break and you could really do some serious damage with that thing.


Make that bitch in an SBR and throw on a heavy-duty muzzle brake and are cooking with gas.



I think you'd drop so much velocity by making it a SBR that it wouldn't be worth having the great 338lm.

Link Posted: 9/8/2010 9:10:32 PM EDT

Originally Posted By packinheavy:

Originally Posted By Kuraki:
30-06 was available. I believe Bushmaster bought the company that was making them. There's no reason you can't, just not much market I'm guessing. Magazines might be a bitch for anything past 10 rounds.

How about BAR(USGI, not civilian model) mags for them?

I don't know how readily available those are any more though.


Take a guess as to what caliber the very first AR was chambered in.

Then guess what mags it took.

WAIT!!!

You already did.

Yup, the very first garage protoype was a 30-06 that took BAR mags. It was, essentially, the "proof of concept" prototype.

Very odd, yet cool looking.

I was bummed that someone bought Cobb because they did it to take the competition out of the market and shelved the Cobb technology as far as I can tell.
Link Posted: 9/8/2010 9:14:21 PM EDT
Above the 308/3006 range rounds, mag fed semi-auto goes out the window with belted rounds.

Besides at that point we are looking at a 15lb rifle, which is pushing it on the weight even by precision rifle standards.

That said, a 33 lupa should be doable and I think work the effort.
Link Posted: 9/8/2010 9:25:40 PM EDT
Meh, I'd rather have one of the customized Garands in .458-I just can't bear to spend over $2000 ruining the history of an already expensive rifle, and don't know if a Century receiver could stand up to it.
Link Posted: 9/8/2010 9:26:54 PM EDT
Originally Posted By shack357:
Meh, I'd rather have one of the customized Garands in .458-I just can't bear to spend over $2000 ruining the history of an already expensive rifle, and don't know if a Century receiver could stand up to it.


Garand in 458, the perfect scout/guide rifle.
Link Posted: 9/8/2010 9:34:16 PM EDT
You can stack at least 10 rounds of belted magnums in a BAR magazine. Looky here...

http://www.securityarms.com/20010315/galleryfiles/3000/3020.htm

.300 Win Mag semi-auto hammer. Fook yeah!

Best,
JBR
Link Posted: 9/9/2010 5:27:00 AM EDT

Originally Posted By desertmoon:

Originally Posted By packinheavy:

Originally Posted By Kuraki:
30-06 was available. I believe Bushmaster bought the company that was making them. There's no reason you can't, just not much market I'm guessing. Magazines might be a bitch for anything past 10 rounds.

How about BAR(USGI, not civilian model) mags for them?

I don't know how readily available those are any more though.


Take a guess as to what caliber the very first AR was chambered in.

Then guess what mags it took.

WAIT!!!

You already did.

Yup, the very first garage protoype was a 30-06 that took BAR mags. It was, essentially, the "proof of concept" prototype.

Very odd, yet cool looking.

I was bummed that someone bought Cobb because they did it to take the competition out of the market and shelved the Cobb technology as far as I can tell.


Sweet! Learn something new everyday. Thanks.
Link Posted: 9/9/2010 5:36:32 AM EDT
Originally Posted By AJK07734:
Originally Posted By vanilla_gorilla:
Couple years back, somebody was making a lower with interchangeable mag wells for different length magazines. Attach the correct magwell for your chosen magazine and caliber, then attach upper, then you're GTG.

Posted Via AR15.Com Mobile

MGI makes them Mack Gwinn playing mad scientist (or engineer in this case) again...cool concept when you pair it with the QCB upper.


Posted Via AR15.Com Mobile


I'm pretty sure COBB was the original creator of the interchangable magwell AR platform.
Link Posted: 9/9/2010 5:39:58 AM EDT
Why? For a market of one?
Link Posted: 9/9/2010 5:40:55 AM EDT
Originally Posted By OKZJ:

Originally Posted By ShootToKill:
Too much $ for the rifle IMO. I reload for my .338lm and still cringe at the thought of funding ammo for a semi in that caliber.
.338 Lapua Magnum AR

Only 13lbs! . Probably upwards of 17-19lbs one you put everything on it... If money were no object I would have one of these. Suppress the thing or get a good break and you could really do some serious damage with that thing.

OK, see, now we're talking. Take something like that but for .270/.280/.30-06/.300 Win and work to bring it in at a price point somewhere around $1200. The biggest pain in the ass is going to be getting barrels made.




Why not look at the WSM and WSSM calibers for a project. Something like the 243wssm or 270wsm

Link Posted: 9/9/2010 3:59:07 PM EDT
I don't think .30-06 beats .308 by a few hundred fps. I think the .308, being shortened and improved, is probably pretty close to being a ballistic equal to the 06. As for belted cartridges not working in a magazine, why wouldn't they? There have been magazine fed rifles chambered for belted cartridges since 1912 or so.
Link Posted: 9/9/2010 4:02:06 PM EDT
[Last Edit: 9/9/2010 4:03:18 PM EDT by DragoMuseveni]
You know what, never mind.

Link Posted: 9/9/2010 4:04:57 PM EDT
[Last Edit: 9/9/2010 4:05:54 PM EDT by ArmyInfantryVet]

Originally Posted By DoubleARon:
I don't think .30-06 beats .308 by a few hundred fps. I think the .308, being shortened and improved, is probably pretty close to being a ballistic equal to the 06. As for belted cartridges not working in a magazine, why wouldn't they? There have been magazine fed rifles chambered for belted cartridges since 1912 or so.

And likewise how the modern .308 has about the same performance as the .30-06 of old because of modern propellents. You can ALSO upgrade the performance of the .30-06 into the magnum realm using modern propellants also, because it has a bigger powder capacity than .308

It's not a one way street where you can only improve the performance of .308 with modern propellants and you can't do the same with .30-06
Link Posted: 9/9/2010 4:07:00 PM EDT
[Last Edit: 9/9/2010 4:09:12 PM EDT by DoubleARon]
Neither is all that impressive with the heavy bullets. Only real place to gain velocity is by going up an H&H based case.

ETA: Or by letting PO Ackley make sweet love to your rifle.
Link Posted: 9/9/2010 4:14:16 PM EDT
I don't know why not. And I love my .308 AR. Needs me to build another rifle––maybe a new cartridge is warranted: the .375 AR Magnum
Link Posted: 9/9/2010 4:24:41 PM EDT
Originally Posted By jimhoff:
I don't know why not. And I love my .308 AR. Needs me to build another rifle––maybe a new cartridge is warranted: the .375 AR Magnum


The .308 case necked up to .375 cal has been done. Dies etc. are all available.
Link Posted: 9/9/2010 5:15:47 PM EDT
Originally Posted By Kuraki:
30-06 was available. I believe Bushmaster bought the company that was making them. There's no reason you can't, just not much market I'm guessing. Magazines might be a bitch for anything past 10 rounds.


could you explain that? i am not questioning your statement, i am just trying to better understand magazine function and build right now...

tia!
Link Posted: 9/9/2010 6:27:56 PM EDT
Hmmm... .375 Ultra Mag might make a good test bed.
Link Posted: 9/9/2010 7:11:20 PM EDT
Teppo Jutsu already has the Rhino series of cartridges, from .338 to .470 caliber. Parent case is the .500 Jeffrey. Goal is to replicate the various Nitro Express cartridges in a .308 length case, from an AR-10 platform.
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