Good to know on both... I was going to LOL about a recoil reducer...

screw on muzzle brake, so you can take it OFF, would do the same thing

jeffe

Buy one of the buttstock weights we service rifle shooters use, it will add 2 3/4 pounds to the rifle and they're only 25 bucks or so and won't rattle. You can also get lead collars that go under the GI handguards to add a couple more pounds.

if you really want to do something on an ar try looking up JP arms. they have a muzzle brake that really works. You can see your hits on multiple shots on PD's