With A2 sights, what kind of groups would you be looking for at 50 yds with a 16" barrel? I'm deciding on whether to keep my 16" HBAR (Bushmaster except for an Olympic fluted barrel) or sell it and get a Colt 6520. The reason is, the only time I've been to the range with it (several years ago) I couldn't seem to get any kind of group - more like a pattern! I'm a pretty good shooter and had not run into that problem before. This was a build with all new parts, and the upper was assembled by a professional AR 'smith. I've learned a lot since then and have decided on the IBZ sighting procedure and have set my rear sight accordingly. I'm going back to the range with it with more kinds of ammo to see if I can get some decent groups at 50 yds so I can adjust the sights for POA which will give me the IBZ zero at 50 and 200. So, I need to confirm this barrel is okay. Would you say a 2" group is about right, or should I be looking for something else? The last time I fired it, at 100 yds, I was getting more like 8" spreads. In truth, I was probably shooting too fast, feeding it M855 and using the large aperture. I just want to give this carbine a fair chance, because I kind of like it. This time I'll use the small aperture, take my time and try some M193. BTW, the Olympic barrel is button-rifled to a 1:9 twist, 4140 chomoly and not chrome-lined.