Never seen these before, but they look like they should be effective at dampenng muzzle flip and recoil.
Just check alignment and tightness.
I have chopped down and rethreaded a few of the Chinese M14 original flash hiders, turning them into muzzle brakes or comps, but eventually decided the amount of work involved wss not worth it.
I designed a muzzle brake SPECIFICALLY for use on M14 barrels that have been chopped .These are marketed by M14.CA. THEY DO NOT MOUNT WITH THE USUAL M14 SYSTEM, but instead require threading the muzzle to AR 15 specs. My design uses a seperate CLAMP ON front sight tower, which is a bit taller.
NOTE: I have experimented extensively with muzzle devices on the M14, and have found some such devices do signifucantly reduce muzzle flip and recoil, resulting in felt recoil similar to an SKS shooting .30 Russian ammo. However, I have also found that modifying the butt stock to a straight-in -line-with-the bore design, is the most effective method for improving control on fast multiple shots. Or else, shooting lighter bullets or loading down the powder.