It says LEO-GOV use only Because some states are still under State bans that mirror the Clinton brain fart. Its easier to leave it on, I guess they could add "Where Applicable".
The #1 error I see people make, and made the same mistake myself, is to go out and start buying more stuff to put on the gun. Get good with the stock gun, not only will you always be able to fall back on the basic iron sighted rifle but you will better learn just what the rifle need to be to suit your needs. All the Swag in the world wont make you any better a shot, so spend the money on ammo. They make a drop in 22 kit for the AR15, its well worth the money and works great. Here is a great 14day practice program, It dose work very well if you hav ethe self dissaplin to stay at it.
http://www.thecombattriad.net/viewtopic.php?t=11
1x9 twist will shoot 77grain depending on the lenght of the bullet. It will not shoot anything that wont fit in the mag, pretty much anything bigger then 77. I notice no change from a 1x7 to a 1x9 with 77grains out to about 300 yards , from there the 1x7 is more stable but both will hit the target. Keep in mind im not the greatest shot either.
