I'm looking for a rifle that will do the following:

1. Be lethal to squirrels, rabbits, racoons, armadillos, snakes at ranges up to 200 yards.

2. Be sub-MOA accurate on paper at 300 yards.

3. Lightweight and easy to carry

4. Low recoil

What kind of configuration should I look at. I would like to be using a bipod but if I can't it's not a big deal. What kind of optic should I look at for hitting those small animals at that range? I've heard a lot of you guys say 3x-4x is good enough but I don't see how that is possible given how far things look through my 10x scope on my 30-06.

Well does it realy have to be "lightweight and easy to carry"? Because allmost any bull barrel will do what you want, but it aint light. A 16" bull might be light enough. I use a Bushnell 6-18X50mmAO scope on my M1A, it works good but it is hard to find you target even on 6 power because of limited field of view, so quick upclose work is out. Look at the kits on model1sales.com maybe you could get a standerd 20" A3kit with a free float tube ($25 extra) then add a bipod, that'd be lighter.

what does a bull barrel do that a normal profile bbl wont?

EDIT: OK, I read that they don't heat up as much but other than the heat affecting accuracy is there any other advantage?

Yes, they take heat better than a conventional barrel. However, there is also an accuracy issue to consider.  Many rifle's point of impact changes on identical shots depending on whether the barrel is hot or not. Having a bull barrel can effectively improve accuracy... Not on a single 'cold shot', but you can get more consistent groups due to the fact that the barrel isn't 'walking' from the heat.

Quoted: Yes, they take heat better than a conventional barrel. However, there is also an accuracy issue to consider.  Many rifle's point of impact changes on identical shots depending on whether the barrel is hot or not. Having a bull barrel can effectively improve accuracy... Not on a single 'cold shot', but you can get more consistent groups due to the fact that the barrel isn't 'walking' from the heat.

Bull barrel harmonics can be inherently more accurate as well.  

In any case - from what the original poster wants.... I'd build a 16" floated RRA chrome moly flat top upper... using a YHM lightweight float tube.  For those requirements... I'd get a decent 3-9x scope.... like a leupold vari-xII.  Bipods add weight, but if you can deal, then connect it to the float tube.  

I am not sure what kind of damage you want to do to the critters.... if you want high fragmentation... you might consider a 20", but a sub-moa capable 20" rifle starts to get heavier.....

well originally my idea was to get a 16" chrome lined barrel with a midlength gas system and YHM FF rails (a bipod would fit better on that than on an M4) and get a scope that goes up to maybe 14x. Would this be accurate enough to nail a squirrel on a tree from 150 yards on the first shot? Do I need to get a bull barrel for this? If it will help a lot I will lug it around. Between a 20", a 16" and a 16" bull barrel, which do you think I would like best?

16 in or 20 in bull bbl
w/ a varible 20x or so scope

i would get a 16 in hbar, but your requirement for submoa at 300 yrds is kinda stiff

Quoted: well originally my idea was to get a 16" chrome lined barrel with a midlength gas system and YHM FF rails (a bipod would fit better on that than on an M4) and get a scope that goes up to maybe 14x. Would this be accurate enough to nail a squirrel on a tree from 150 yards on the first shot? yesDo I need to get a bull barrel for this? IMHO, no If it will help a lot I will lug it around. Between a 20", a 16" and a 16" bull barrel, which do you think I would like best?

The 16" midlength with the YHM FF sounds like a good setup if you'll be doing a lot of carrying around. The sub MOA at 300 yards might be a little tough to achieve, but you'll be close with good ammo, scope, and mounts.

I have a 16" Bushmaster with the stock HBAR that comes on them. Added a Burris 3-9 Fullfield II scope mounted on a GGG GS-1 rail, and attached a Harris bipod to the handguards using a Harris #5 adapter. I used that rifle last year to shoot prarie dogs. Got hits out to around 400 yards no prob after doping the wind. Its probably not the best/coolest setup, but thats all I could afford at the time. Was more than satisfied with the performance.

Would a 24" SS Bull barrel make a big difference in accuracy at 300 yards over a 20"?

DocBrooks, check the equipment exchange dennys guns has a run of custom midlenght barrels that are:

"16", Midlength gas system, 1:7 twist. Barrels are air guaged Stainless Steel and made for us by John at WOA, custom chambered with matching bolt. Guranteed sub MOA with Match Ammo"

Not the best twist for varmit rounds but looks like a quality set up.  

Quoted: Would a 24" SS Bull barrel make a big difference in accuracy at 300 yards over a 20"?

No.  Both barrels being of the same quality, the accuracy potential will be identical.  A QUALITY 20" barrel (WOA, CLE, etc..) will out shoot a cheaper 24" barrel all day long.

Quoted: well originally my idea was to get a 16" chrome lined barrel with a midlength gas system and YHM FF rails (a bipod would fit better on that than on an M4) and get a scope that goes up to maybe 14x. Would this be accurate enough to nail a squirrel on a tree from 150 yards on the first shot?

Maybe.  With match ammo, and a quality chrome lined 16" barrel... you *might* be MOA, or just under.  Thats a big maybe.  Some chrome lined, non-match barrels just aint gonna shoot better than MOA (and that is a lot to ask... many *shooters* cannot hold MOA)  So, lets assume you get a good one, and it can hold MOA.  That means at 150yds, you will be holding a 1.5" group.  About the size of the squirrel width (body/head/center mass)  You will need to understand where your zero is.... sighted in for 50yds, your shot at 150 will be somewhere around the peak of the trajectory, and will be around 2" high at this point.... so to get a hit, you just need to know this.

All that being said... sure, it's doable, with match ammo, and you holding perfect....  Even the BEST gas guns out there are only gonna hold .75" at this distance.... so its still a great shot to take out a squirrel at 150 yds on a cold bore.

Do I need to get a bull barrel for this?

No.  But you will get better groups from a match barrel.  Doesnt have to be a bull one.  Match barrels and chrome lined typically do not go hand in hand.

If it will help a lot I will lug it around. Between a 20", a 16" and a 16" bull barrel, which do you think I would like best?

Personally, I feel a quality 16" chrome lined barrel will probably meet most of your needs.... unless you find that this just is not accurate enough.... for long shots.  Some people here have acheived sub-moa from a bushmaster 14.5" barrel.... so thats a crap shoot.  If after reading this, you want the best accuracy potential, and to maintain the flattest trajectory, and retain the most velocity, then I would go with a 20" match stainless barrel... but not a bull to keep it light.  

Of course, all this depends on you using some really high quality ammo, or handloading... which you havent commented on.  If you just wanna go buy some walmart white box stuff.... then it really wont matter what kind of barrel you shoot.  I have a 20" bull that is capbalbe of .5MOA with black hills 77 SMK's.... but it still shoots 2-3MOA using Wolf.  

Quoted: DocBrooks, check the equipment exchange dennys guns has a run of custom midlenght barrels that are: "16", Midlength gas system, 1:7 twist. Barrels are air guaged Stainless Steel and made for us by John at WOA, custom chambered with matching bolt. Guranteed sub MOA with Match Ammo" Not the best twist for varmit rounds but looks like a quality set up.

This sounds like an excellent reccomendation for those who are serious.