I have a bushmaster with two uppers
Flatop 20" (bought new) With 20 X scope I can shoot
1 1/2"-2" with SA,1" with some handloads and some
factory loads-this makes me happy

Bought a bushmaster 14 1/2" (16" with ak comp)
flatop with matching bolt ect.Sold as used but It
looked like it had hardly been fired. (hardly any
marks on the bolt ect)
With my same scope this upper will hardly make
3 or 4 " with any ammo and goes near 5" with SA
or mil spec ammo
  I have tried a good cleaning and as far as I
can see (without a borescope) the throat ,muzzle
and bore look mint .
   Is this all I can expect from a 14 1/2" with
a ar break ?
   Should I have the headspace checked ?
   What else should I be looking at ?
Thanks-NHSPORT