How much  accuracy differences are there at mid-ranges.  I understand the cause/effect of floating or not-floating, I'm just trying to decide if it's worth the investment for a mid-range critter killer.

Define "mid-range" and "critter?"  

Haha... seriously, IMHO, spend what you can, and enjoy it.  I'd be willing to bet that with handloaded ammo and a scope, my Superlight non-FF'd barrel could turn in some impressive groups if shot from a vise and the rate of fire was kept slow enough.  If you're going to go farther out, though, and shoot faster, from a rest,...

Poke around here, keep reading--you'll likely get the flavor of what you'll need.  

mid-range - 100-300
critters - coyote and the ever evasive coffee can

bump

.......kind of depends on what you`re using now......and...you can go free float rather reasonably....unless you "need" to spend a lot.....you can get a tube for about 40$....if you want to do the work.....if you have a nm bbl now...or what you have is doing 1"-2" groups @ 100.....you wont realize much improvement......if you look at the fancy tubes....or match type....it will cost quite a bit more.........

Quoted: mid-range - 100-300 critters - coyote and the ever evasive coffee can

At those ranges a clapped out M16A2 I had in Basic Training would hit everything you need.

IMO:

100-300 meters (close range)

300-600 meters (medium range)

600+ (long range)

I can't count how many times I've heard bench jockeys at the local gun shop bragging about their amazing hits at 100 yards + using a 10 powered scope and some kind of pimped out bolt action. I can hit man size target out to 300 yard with any AR variant properly sighted in, it's not exactly impressive as any schmoe in the military with enough range time can do the same.

Quoted: Quoted: mid-range - 100-300 critters - coyote and the ever evasive coffee can I can't count how many times I've heard bench jockeys at the local gun shop bragging about their amazing hits at 100 yards + using a 10 powered scope and some kind of pimped out bolt action. I can hit man size target out to 300 yard with any AR variant properly sighted in, it's not exactly impressive as any schmoe in the military with enough range time can do the same.

+1