I currently have a 23" heavy stainless barrel on my prarie dog/varmint AR. I am looking into picking up a 16" upper for it for walking around and popping the occasional woodchuck or maybe a little coyote/fox hunting. My questions are as follows. Will a standard weight barrel deliver minute of woodchuck accuracy out to 200yds. Would a heavy barrel show much more accuracy potential? Also, is a free float handguard necessary for this application. Any and all opinions are appreciated. I do realize it is hard to say that one barrel type over another will be the best all the time as I realize some barrels just do not shoot.
Thanks,
Tuco

Tuco, I just took my 16" Model 1 to the range today, with some handloads...I was trying to see if I could get it to break moa.  

This is a standard weight barrel, but it looks, in terms of thickness, exactly like my Armalite HBAR...so I don't know what the difference is. Maybe it's smaller under the handguards, but I forgot to look.  

I also have the Fulton Armory Liberator II tube on there.  I did manage to go sub moa with one of the loads, in all 4 groups, if you'll allow me to discount the flyers lol...the guy on my left was shooting an FAL, and the guy on the right an M1A...so everytime they fired, it litereally moved my rifle...I had to re-acquire my sight picture, and try and sqeeze off a shot before either one of them.  Not the most ideal conditions hehe.

This same rifle was doing very consistent 1moa with my standard 55gr Nos. BT load, so I don't think you'll have too much trouble getting the accuracy you want.  BTW, Model 1 is rumored to use Shaw barrels...M&A uses Wilson match barrels on a lot of their stuff.  

I have a Model 1 lightweight rifle I just put together, but I didn't have enough good ammo today to see what it could do...but it was holding my 55gr FMJ plinking load to about 1 1/2", so it wasn't too bad.  I'm sure I could get that to 1" if I tried.  I didn't really build that rifle to do anything more than stay under the bed/in the trunk, so I'm not looking for super match accuracy.  

Unfortunately, I can't answer your question about whether the tube makes any difference...I never really tested the 1st rifle before I put the FA tube on there...but a standard 16" tube doesn't weigh much, so if you're not looking for super lightweight, it probably couldn't hurt to have one.