LAR-8 Upper Build

[MidRangeCrisis]

Digging through the forum has been unrevealing.

I am working on a build for a recently acquired LAR-8 lower and some bits I managed to pull together. I have an upper receiver and the impossible barrel nut besides a handguard and a selection of barrels. I need a bolt and the barrel extension.

So, is the barrel extension from another AR-10 type suitable?

 

[6.5SH]

Until someone with more direct experience chimes in you might take a look here:

AR-10 308 AR Compatibility Reference Guide | AR 308 vs AR 10

Compatibility Reference Guide - Understand and research the parts interchangeability and differences between the AR-10, AR-15, 308 AR and AR 308 rifles

308ar.com

 

[MidRangeCrisis]

Until someone with more direct experience chimes in you might take a look here:

AR-10 308 AR Compatibility Reference Guide | AR 308 vs AR 10

Compatibility Reference Guide - Understand and research the parts interchangeability and differences between the AR-10, AR-15, 308 AR and AR 308 rifles

308ar.com

You are a gem. Thanks.

 

[Hetzer]

What is the "impossible" barrel nut? I know they have their own version, just curious as to why that description.
I have a 20" Varmint in .308, I've given thought to getting a Creedmoor upper for it. 'Cause, why not?

 

[MidRangeCrisis]

What is the "impossible" barrel nut? I know they have their own version, just curious as to why that description.
I have a 20" Varmint in .308, I've given thought to getting a Creedmoor upper for it. 'Cause, why not?

Just a bit of hyperbole. It's proprietary to RRA (notorious for gluing in their barrel nuts in the first place) and they go to great lengths to emphasize the danger of using anything else while not producing enough spares to allow for a home build. That and I cannot locate an in-stock or in-production alternative.

A little heat takes care of the loctite if there is any. Looks like DPMS barrels and extensions are workable alternatives as well.

 

[Hetzer]

I looked at their site this morning and every LAR8 barrel I looked at showed as "Indefinite Backorder".
The Nut and Extensions did not show that. I take it you tried to order them and they are not available?

 

[MidRangeCrisis]

I called in for a separate issue and they stated they would not sell parts until the backordered assmblies were caught up when I asked about it.

I'll put in an order for some small parts and see what happens. Worst thing they can say is no right?

 

[Hetzer]

That's true.
Their complete Creedmoor upper is $870-890. I don't think I could piece one together for less in my own case.