I pulled my last $79 Spikes SL15 Striped Lower out of the Safe and decided to build a Big Bore AR and I have decided to go with the 458 SOCOM because it allows me a greater variety of  Reloads to work with. I know RRA builds complete uppers but I thought about building It the way I want it set up, RRA does not sale parts for the 458 SOCOM its either the a complete upper or a complete rifle.

The problem is finding all the parts I need, I have found a MGI 16.5" SS barrel and bolt but the barrel is threaded for a 11/16 x 24 TPI  Flash Suppressor and I have been trying to find a A2 style equivalent but I have come up empty. I am looking for options from any one who has built one up from scratch. I contacted Steve at ADCO to see if it was possible to turn the barrel down to 5/8 x 24 for a open up .308 FS but he said that was a no go because it would thin the barrel out to munch for a 458 bore.

I am looking for any suggestion  or part source

Thanks
Richard
Semper Fi

Trust me, 5/8 x 24 works just fine... you might consider x 32 as there a few more options out there.  Plus you can take various other muzzle devices and modify them - I can get one of the RRA A2 FH with the x 32 thread for you

All 3 of my .458 SOCOMs (and a 4th in the works) wear a 5/8 x 24 thread and use opened up YHM Phantom .308 FS.  There is plenty of meat there so don't worry about that.

http://usera.ImageCave.com/Spook/58458.jpg

Barrel stub from 10 twist SOCOM rifle I just built . 5/8 X 24 threads shown. Plenty of steel left.