308 AR upper compatibility

[TrueBlue711]

I know AR-10s are a little more picky when it comes to building one using parts from different companies than the AR-15 little brother. I just got an AR-10 lower based on fitting the DPMS Gen 1 design. Does anybody have a list of companies that make AR-10 uppers with the same fitting as the DPMS Gen 1 so I know what to choose from?

[navajo]

Always better off getting U/L from same maker. Always.

[agtman]

Always better off getting U/L from same maker. Always.

Definitely this ... especially in .308/7.62.

[TrueBlue711]

Always better off getting U/L from same maker.

Agreed and I normally would. The lower I got was from TN Arms though, which is a polymer lower and they don't make uppers. Their website suggested Aero Precision however.

[greentick]

Nothing wrong with Aero...

[stagpanther]

Agreed and I normally would. The lower I got was from TN Arms though

That's a tough one--in that case I would call TN Arms up and simply ask--"which uppers are you sure your lower is a good fit for"--meaning they know pins will work well along with proper clearances for everything else. As nice as an AR lower looks--I wouldn't want one for a paperweight.

[ed308]

Aero is suppose to work with DPMS .308. Whether it does, who knows.

[stagpanther]

Aero is suppose to work with DPMS .308. Whether it does, who knows.

Haven't tried their uppers for "DPMS compatibility"--but the two 308 lowers I bought from them have been abysmal in their ability to work with other manufacturer's uppers. As advised above, in general buy upper and lower from same manufacturer whenever possible when venturing out on the 308 thin ice.

[Stats Shooter]

Once you venture away from the 556x45/223 compatible AR uppers/lowers, you lose a lot of the ability to source parts from different makers. Cartridges like the .300 blk are fine because they have the same features excluding the chamber/barrel (pretty much). But other cartridges like .450 bushmaster, .50 Beowulf, and even the .308 will have subtle differences, yet substantial enough to limit where I would source parts.

For the most part triggers, furniture, etc are still modular. But uppers, lowers, bcg's may not be. Magazines can also be picky in the non-556 AR world. My AR-10 is piston driven and only works well with magpul mags. So, i pretty much have only one bcg option.

I'm no AR "build" expert. But I have done a few, and am building a .40s&w AR right now and it has its own quirks I have to deal with.

[stagpanther]

am building a .40s&w AR right now and it has its own quirks I have to deal with.

Blow-back? I just built a 10mm (probably uses the same or similar components except for the barrel and magazine). Not to change the subject.

[Stats Shooter]

Blow-back?

Yes...I don't see any way around it if I want to build it myself. There are a couple places that build DI AR's in pistol cartridges....But no way to source parts for DIY unless you do blowback.

But back to this thread's question. The .308 isn't as difficult to build as a pistol carbines as far as sourcing parts from what I can tell....But again I would be leery of buying mismatched uppers, lowers, and I would ask the upper manufacturer about bcg suggestions and barrel.

Stagpanther I think, in a thread a while back, built a nonshooter .308, sourcing parts from PSA. His experience might be something you ask about

[stagpanther]

I've built 6 308 platform AR's so far; and here are the "gotcha's" I've experienced so far in no particular order:

1. Different alignment of pivot pin holes. This is one of the worst problems--and one that Aero 308 lowers seem to be the most flagrant "problem children" of. The holes may be off by only a thousandth of an inch or so--but that's enough to cause problems with alignment between receivers--as well as preventing the pivot pins to engage if there is a horizontal offset in the pivot pin holes between the upper and lower.

2. Different pin sizes--this is a common problem as several manufacturers use different length pivot pins.

3. Incompatible lower buffer tube height: I've had a couple of lowers with buffer tube collars that were too thick or high--preventing the charging handle to clear.

4. Slightly different fire control well cut-out designs--like receivers, there may be a slightly different design in how the LPK's install into the lower--for that reason it's best to use the LPK made by the same manufacturer as the lower. safety selectors are not necessarily interchangeable.

Those are few that pop up off the top of my head--I'm sure there are many more.

.308, sourcing parts from PSA.

It shoots fine in terms of reliability now--I had to do some tuning but it was otherwise their complete upper and lower. It's not very accurate though--But for a 16" carbine gas system I wasn't expecting miracles anyway. lol

[berettaprofessor]

Always better off getting U/L from same maker. Always.

This. I started with a Stag lower. Stag advertises it's AR10's as DPMS compatible. Turns out their lowers only fit their own uppers....and then, yes, you can use DPMS compatible furniture on it.