wow I got a much tighter group with the PDX out of my M4. all 4 (slug plus 3 buck) were within a 4 inch circle at 15 to 20 yds.
also the OP only asked what the marines use.... he didnt say he was going to use it for home defence.
I don't judge by looks - function over form. it works great and feels good in my hands. and has four rails. I dont mind some gunsmithing , to me thats a challenge to overcome
wow $55 bucks for that? you could get a Mako foregrip with rails on both sides top and bottom for a few more bucks. I really like it after a little dremel work it fits perfect and it protects my hands from the top of the barrel when its hot.
pls make sure you read my post before you crap it. I did not list USA made parts, I listed the parts I recommend he adds to his M4. he didnt ask what parts he needs for 922 he asked what he should spend his $$ on.
tocomply with 922 you can not increase the mag capcity unless you add three USA made parts. or the 922 police will get you.
I would get.
1) GGG bolt relaease pad
2) carrier comp Ti tube