AR10 interchangeabllity

[Metal God]

I had a thought the other day and want to ask about it here . A little while back I decided to only buy certain calibers of firearms cus I was starting to get to many different ones . I have now decided rather then one or to centerfire rifle calibers . I will just stay in the same 308 cartridge family and neck up and down if needed . This would allow me to shoot with the same brass 243 , 260 , 308 , 7mm-08 , 338 Federal and 358 Winchester . All of those use the same 308 as there parent case .

Now to the real interesting part . What if I go with the AR10 platform and just change out the barrels and bolt as needed or even complete uppers . I was first thinking about this and using a bolt action savage but the more I think about it the AR10 would be awesome to do this with , if it is indeed doable

I know the AR15 can just be changed around and most of the parts are interchangeable . I also know that is not the case when it comes to the AR10 .

Can you just put any barrel on a AR10 ? or would I have to stick with the same manufacturer that made the upper and lower .

Would I need the barrel maker to match a bolt to the the barrel and receiver ?

I found an AR10 in 338 Federal , do they make a barrel chambered in 243 .

Does the 338 Federal fit in the 308 mag and for that matter would the 7mm-08 and 243 as well

I have more questions and to say on this but lets see where this takes us first .

Thanks
Metal

[robert101]

"I will just stay in the same 308 cartridge family and neck up and down if needed ."

Although resizing the neck is certainly viable, I would not agree that resizing over and over again is a good thing. Now you didn't specifically say that, but this thought did come to mind when I read your opening.

[crazychinaman]

rifle

if you want a rifle that can be interchanged with differant calibers in the AR .308 platform.You must buy the LMT .308 rifle.It is very easy to change calibers.Very hard to find right now.The British army uses them.

[CCrawford]

Same .308 mag and bolt, as the middle and back of case size is not changing. First thing to know is which family does the AR-10 you speak of belong to? The "AR-10" is a specific ArmaLite gun. It is not fully compatible with the DPMS LR-308. The uppers and lowers really don't fit each other. Everyone else's .308 pattern are one of the two really with Fulton being the most oddball. Your research will give you the two families full membership, but the quick thought is that ArmaLite, Noveske, and Aero are the same (slanted frame) and everything else is DPMS (rounded frame).

I would also suggest some time at AR15.com and read up in the "AR10 & AR180" and "AR Variants" forums and especially this sticky in the 10 forum for the facts of the matter.

The good news is that each family does have the full range of barrels available from the makers and aftermarket.

Most folks who do the type of thing your suggesting do complete uppers instead of just barrels because of the ease and the optics stay sighted in. It is of course more to much more expensive depending on your taste in optics.

Lastly, I think Robert is quite correct in that you will not want to continually change the neck diameter of the brass. You will want to have dedicated brass as the continually worked brass necks will split and not last very long and it over time would cost more money than you would save unless you have access to a bunch of brass. But, if that were the case, you wouldn't have to worry about it in the first place.

Good Luck,
Criss

[ar15barrels]

There are two different standards as to where the gas port is located and therefore how long the gas tubes are: Armalite or DPMS.

Otherwise, the 308 mags will feed from 243winchester to 338federal.
I have not tried doing a 358 yet.

[Metal God]

Alright , now that I know this is very doable . Let me tell you why I was thinking to do this and address your post as well .

This whole thing stems from this last panic rush on ammo and supply's as well as SHTF scenario . What I originally wanted was a rifle chambered in a cartridge that the ammo was readily available but not so popular it would be the first to fly off the shelves . I wanted something that would be capable of taking any game in North America . My first thought was 25-06 or 7mm-08 yes a little under powered but could work . After posting this idea on another forum some came up with the idea of sticking with the same cartridge family and get an extra barrel or two in the odd chambering's . This really appealed to me and seeing how I already have a few 308s I decided the 308 would be my cartridge of choice .

This would mean I would really only need 308 brass and it's the round I like to shoot most . This idea is about redundancy and the ability to have multiple chambering's in one platform and the ability to take any game in North America . This is not about sizing from 338 to 243 back to 338 then 308 with one cartridge . I know that's a bad idea . It's about , when in a pinch and all you got is 308 brass you can still if need be load any one of 4 or 5 different rounds if you had too and be GTG .

My first thought was to use a bolt action rifle like a Savage cus they are one of the easier rifles to change barrels on and I already have one in 308 . I liked the 7mm-08 but when I started looking at the ballistics on the 338 Federal I started liking that round more and more . Savage does not offer the 338 Federal so I did a quick search to see what rifle manufacturer makes a rifle chambered in it . This is when I came across the Amerlite AR10 chambered in the 338 Federal . BING the light bulb went on . Holy cow this is the perfect SHTF idea . I would still be able to stay in the 308 family and changing from caliber to caliber would be much easier then a bolt action rifle .

I would want the rifle chambered in 308 most of the time . While having barrels and or uppers ready to go in 243 and 338 . one of the things I'm still not sure about is if I would need a separate bolt for each of the chambering's . I would think cus there is no universal spec on the chamber and barrel extension like the AR15 . The head spacing would most likely be different for each chambering .

After the bolt issue is resolved I would think there may be a buffer and buffer spring weight issue per-cartridge . An adjustable gas block could help that issue though right ?

wow that was a mouth full . You guys have any more thoughts on this . What would be the best manufacturer to to do this with ? I saw LMT , Amaelite , I'm not a fan of DPMS so I will not use them unless they are the best and only ones to use . What about Rock River ?

I'm not opposed to building this thing from scratch as well .

[ar15barrels]

I would want the rifle chambered in 308 most of the time . While having barrels and or uppers ready to go in 243 and 338 . one of the things I'm still not sure about is if I would need a separate bolt for each of the chambering's . I would think cus there is no universal spec on the chamber and barrel extension like the AR15 . The head spacing would most likely be different for each chambering .

After the bolt issue is resolved I would think there may be a buffer and buffer spring weight issue per-cartridge . An adjustable gas block could help that issue though right ?

wow that was a mouth full . You guys have any more thoughts on this . What would be the best manufacturer to to do this with ? I saw LMT , Amaelite , I'm not a fan of DPMS so I will not use them unless they are the best and only ones to use . What about Rock River ?

The easiest way would be to get an LMT MWS and two extra barrels.
I can re-barrel those two extra barrels so that you can share the same bolt across all three barrels.

[robert101]

Randall, great idea and that thought is very appealing. Off topic, but, you make some great suggestions here in the forums. I've never gotten any work done with you but I will certainly keep you in mind as a new build comes to reality.

[sigstroker]

Armalite sells .243 uppers for their AR-10. .243 and .308 pretty much covers what can be done with that case. That's why all the other wildcats are pretty much dead calibers.

[Metal God]

I like thwe LMT and I knew they were spendy but WOW 3k is really pushing the budget .

I can re-barrel those two extra barrels so that you can share the same bolt across all three barrels.

Could you do 2 or 3 bolts that would fit all 3 barrels . I would want at least 1 extra spare bolt , maybe a complete BCG

Armalite sells .243 uppers for their AR-10. .243 and .308 pretty much covers what can be done with that case.

I was just on armalite's web-site . They sell the AR10 upper in 243 , 260, 308 , 338 . I'm assuming when you say 243 & 308 covers what can be done . You mean all that is popular or all that you would do . Have you checked out the 338 .It hits with almost 2,800 foot lbs @ 100yds It can deliver 2000lbs of energy out past 300 yards . Compared to a 175gr 308 just barely getting 2k at 200yds . I like this round for what my plan is .

[ar15barrels]

I like thwe LMT and I knew they were spendy but WOW 3k is really pushing the budget .

Could you do 2 or 3 bolts that would fit all 3 barrels . I would want at least 1 extra spare bolt , maybe a complete BCG

You save the money by only having to have extra barrels, not complete extra uppers.
I can fit the barrels to multiple bolts, but then I recommend you dedicate one bolt to each barrel and only use each bolt with each barrel.
No Ned for an extra carrier unless you just want one...

[captbilly]

What is different about LMT?

if you want a rifle that can be interchanged with differant calibers in the AR .308 platform.You must buy the LMT .308 rifle.It is very easy to change calibers.Very hard to find right now.The British army uses them.

Is there something specific to the LMT that makes changing barrels easier than on an AR-10 or LR308.

[ar15barrels]

Is there something specific to the LMT that makes changing barrels easier than on an AR-10 or LR308.

The barrel is clamped in with two crossbolts instead of retained by a barrel nut.
1 minute barrel changes due to the monolithic upper and handguard system.