Im considering getting another upper in either the Bushmaster M4 or Bushmaster heavy 16". Basically the same uppers except the haevy 16" has a thicker/heavier barrel.

Anybody know how the accuracy compares on these? or at least what kind of groups you've managed with either. Thanks.

anybody?

I have the version with the 16" heavy/straight-sided barrel.  A buddy of mine has the same rifle, except his barrel is the M4/military profile.  Both have similar numbers of rounds through them, and no modifications.  We shot next to each other at the range a while back, then traded rifles.  I noticed no difference in my groups at 100 yards with iron sights, and neither did he.  (Obviously the groups were in a different place, but no change in size.)  My opinion is that the accuracy difference is immaterial at the distances most people shoot unmodified Bushmaster rifles.  

I am REALLY pleased with how this rifle shoots.  I can do 3" groups at 100 yards with iron sights off a bench, no problem.  Two inch groups if I take my time.  

I suspect that the M4/military profile will heat up and cool off quicker, since there's less metal.  Perhaps that means it's not as strong, but as long as you're not prying open ammo crates with your barrel you should be fine.

 

If you decide to install a forearm rail system and add any accessories, some people have noticed a difference in weight between the HBAR and M4 contours.

Steve at ADCO, Wes at MSTN, or any of the really well informed industry partners on the EE can tell you all about it...

Quoted: I have the version with the 16" heavy/straight-sided barrel.  A buddy of mine has the same rifle, except his barrel is the M4/military profile.  Both have similar numbers of rounds through them, and no modifications.  We shot next to each other at the range a while back, then traded rifles.  I noticed no difference in my groups at 100 yards with iron sights, and neither did he.  (Obviously the groups were in a different place, but no change in size.)  My opinion is that the accuracy difference is immaterial at the distances most people shoot unmodified Bushmaster rifles.   I am REALLY pleased with how this rifle shoots.  I can do 3" groups at 100 yards with iron sights off a bench, no problem.  Two inch groups if I take my time.   I suspect that the M4/military profile will heat up and cool off quicker, since there's less metal.  Perhaps that means it's not as strong, but as long as you're not prying open ammo crates with your barrel you should be fine.

Any chance of getting sub 1" groups with these? Ive heard people here say they can with an M4, I doubt it. Ive managed about .8" with my DCM upper. Granted Im not looking for any amazing accuracy with this, but still would like to consistently make 1.5-2 off the bench. Might have to go for a stainless free floater.

Quoted: Any chance of getting sub 1" groups with these? Ive heard people here say they can with an M4, I doubt it. Ive managed about .8" with my DCM upper. Granted Im not looking for any amazing accuracy with this, but still would like to consistently make 1.5-2 off the bench. Might have to go for a stainless free floater.

I would not count on sub-MOA without substantial work (such as a free-floater barrel, like you said).  My preference is to look to bolt-action for that kind of accuracy.    

Using optics, I think 1.5-2 off a bench won't be a problem at all.  My eyes aren't good enough for better than 2" at 100 yards through iron sights.  

14.5" 1/7 Bushmaster M4 govt profile, FF Rail, 2 stage trigger, TA31, 75 grain match Black Hills Red Box, benched gave 1" groups fairly consistantly.  If you shot 5, 5-shot groups at 100 yards you'd have more than 1 group at 1" or less.

I started with a HBAR 16" Bushmaster for my first rifle... it was a mistake.  The HBAR is dead, useless weight on a factory barrel.

I can't speak about Bushmaster from personal experience (so I won't), but my inexpensive Olympic 16" heavy w/ free float can shoot sub moa with good ammo and some concentration on my part (and using a 9x scope for my mediocre eyes). The last 200 yard paper I punched grouped 4 of 5 in 0.97" - I pulled one (I'm not a great shooter), opening 5 of 5 to 3.5". Those 4 were under 0.5 moa -  not a surprise as I normally see 0.5 to 1 moa.

Identify your priorities and build the tool to satisfy the intended/expected task requirements - you may not need the free float/HBAR or arguably minor accuracy advantage (mere bragging rights, or utilitarian necessity?). Good luck.

ac

Quoted: I can't speak about Bushmaster from personal experience (so I won't), but my inexpensive Olympic 16" heavy w/ free float can shoot sub moa with good ammo and some concentration on my part (and using a 9x scope for my mediocre eyes). The last 200 yard paper I punched grouped 4 of 5 in 0.97" - I pulled one (I'm not a great shooter), opening 5 of 5 to 3.5". Those 4 were under 0.5 moa -  not a surprise as I normally see 0.5 to 1 moa. Identify your priorities and build the tool to satisfy the intended/expected task requirements - you may not need the free float/HBAR or arguably minor accuracy advantage (mere bragging rights, or utilitarian necessity?). Good luck. ac

Ive got my DCM upper for great accuracy/varmint shooting. This upper would be first for blasting crap ammo at the range. AKA "bargain priced target shooting". And second as a defensive rifle should I ever need it. Under 1.5" groups at 100yds is fine.

The DCM shoots great groups, but its extremely picky what ammo will even cycle in it. The only commercial ammo it shoots is Federal and Black Hills. It will shoot some high quality M193 and M855 like Winchester, Federal, IMI, and Lake City.   But try some wolf, Winchester white box, remington, S&B, PMC, PMP, and just aobut anything else and it will jam right up.