Coal Dragger
member
Those results at 100 yards with a crude BUIS are quite acceptable. Could a NRA high power or service rifle competitor shoot tighter groups with iron sights? Absolutely. They're also running a match grade barrel, match trigger, heavy fixed stock, and will be using extremely refined aperture sights with adjustments that are rock solid. Not to mention carefully tuned match ammo.
For the OP I humbly suggest upgrading your trigger to a Geissele SSA, or SD-C (I love the SSA-E and SD-E but they're awfully light for a duty/working gun). I put an SD-C in my Colt M4A1 SOCOM II, and without a doubt has been the best upgrade to my practical accuracy with that carbine. If you then want to really see what your BCM can do, you're going to need to invest in some optics. A well set up M4 type carbine with a free floated chrome lined barrel, good ammo, a good optic, and a shootable trigger can easily be a sub MOA weapon. Mine has given me some nice groups with hand loads, even holding under MOA for a 10 shot group. Kind of tough to complain about results like that out of a semi-auto with a NATO spec chamber made to run reliably when hot, cold, wet, dry, dirty, clean, and everything in between.
For the OP I humbly suggest upgrading your trigger to a Geissele SSA, or SD-C (I love the SSA-E and SD-E but they're awfully light for a duty/working gun). I put an SD-C in my Colt M4A1 SOCOM II, and without a doubt has been the best upgrade to my practical accuracy with that carbine. If you then want to really see what your BCM can do, you're going to need to invest in some optics. A well set up M4 type carbine with a free floated chrome lined barrel, good ammo, a good optic, and a shootable trigger can easily be a sub MOA weapon. Mine has given me some nice groups with hand loads, even holding under MOA for a 10 shot group. Kind of tough to complain about results like that out of a semi-auto with a NATO spec chamber made to run reliably when hot, cold, wet, dry, dirty, clean, and everything in between.