What is up w/ this Nat Match M1A muzzle device ‘attachment’?

[Lefty223]

FYI, a friend recently purchased what was alleged to be and appears to be a National Match built M1A. Many parts have the Nat Match markings on them. And he reports it is a tack driver ... but what is this “tensioned nut” arrangement that connects to the bottom of the flash suppressor or muzzle device? Any ideas?

Attachment 53901

[Tx_Aggie]

M14/M1A rifles, with the exception of some of the newer shorter barreled Springfield Armory guns, have unique a muzzle geometry/thread pattern. They use castle nut style devices like that to attach the front sight/muzzle device combination (sometimes including the bayonet mount). There are aftermarket adapters that have a 5/8x24 thread in place of the muzzle break on your friend's rifle, though if it's a nicer older rifle I would probably leave it alone.

Smith Enterprises makes several alternatives, including a few threaded suppressor adapters. I think Delta P Designs also makes a 5/8x24 suppressor adapter.

[Lefty223]

Thanks. I suggested that perhaps the rifle has been built in a State (aka Kalifornia) that forbids threaded muzzles. And perhaps someone machined the threads off a castle nut, made the device & ’swing arm’ feature, where it is now tensioned into place (slip-fit over the end of muzzle ‘stub’) and secured by the bolt/nut off the bayonet groove.

[mack7.62]

That looks like a M14E2 muzzle stabilizer, it is meant to install over the flash suppressor and help control the M14E2 squad auto rifle firing full auto along with the pistol grip stock, bipod and front hand grip.

[Lefty223]

Mack nailed it ... thank you! Why it’s on a NM rifle? Well, I’ll let me friend figure that part out, haha!