does it matter what ammo i shoot? i will be shooting 5.56 65g for home defence and for practice.if it does matter what brand and gran would be best? thanks
Yes, it matters. Opinions on what ammo is “best” for self defense vary widely.
I have magazines loaded with 60 gr Hornady TAP - most seem to prefer the 75 grain but my main “go to” rifle is blessed with a 1/9 twist so I opted for the 60 grain ammo.
For target shooting I use a variety of Federal and Winchester 55 grain FMJ ammo. And some of the Wal-Mart value packs which seem to shoot pretty well. These rounds generally are more than accuarate enough for me at this stage in my shooting skill. 
I have some of the Privi 75 gr match ammo, too but have not shot it yet.
For general can plinking, I use whatever Wolf ammo was on sale, 55 grain or 62 grain. Never had any problems with it, ever - but at 100 yards the group size looks like a shotgun hit the target, so I keep it to close range plinking and it more than suffices for that. Some folks don’t like it at all. YMMV.
Most importantly be sure and function test your self defense ammo in the rifle that it will be used in. In a perfect world every rifle could shoot every round, but that’s not always true. Just because it’s “good” ammo does not mean it will feed in your gun. You never know. This advice applies to any self defense round and any gun, of course - not just AR’s.
the ar that i ll be using has a 1:7 twist do i have to shot heaver bullets with that or is it just better?thanks
Read:
www.ammo-oracle.com
I’ll second the above poster’s suggestion to read what the ammo oracle has to say. It’s all a good read.
I don’t believe you have to shoot only heavier bullets with a 1/7. All but the lightest should should fine, certainly 55grain+.
There has been several discussions on this topic on this forum … search a bit and I think you’ll find a couple of threads with some good info.
I’m running 55gr .223 TAP red box for home defense out of my 11.5" SBR…
