moonglorious61 said:
I have a preban Colt H-bar Sporter that is labeled 5.56 on the barrel but .223 on the lower. Which is it? I have looked around online and found that Colt makes only 5.56. I have also read that many manufacturers often mislabel their firearms in this case. The reason this comes up is because my gun refuses to shoot 5.56 rounds it repeatedly fires and ejects a round but fails to chamber the following round, in addition to this it also will pop primers making me think this chamber is in fact a .223. Does anyone know for sure which it may be? If it is a 5.56 why is this happening?
I'm a long time Colt AR owner and had six preban Colt rifles and carbines before and the thing with Colts are that the chamber size are marked on top of the barrel which in your case 5.56, the markings on the lowers are just old rollmarks that Colt never changed, ignore the lower markings.
Is your Colt H-BAR a rifle or a carbine?
My current Colt LE model AR6721 AR-15A3 tactical carbine is marked 5.56 on the barrel but .223 on the lower receiver and I always use surplus 5.56 ammo and no problems.
The problem that you described is short stroking and there could be a number of things causing it like gas leak, the bolt carrier group dragging during the recoil cycle, buffer and buffer tube problems, etc.
The only time I had a similar problem with my former Colt R6600 AR-15A2 H-BAR Sporter rifle was I had a lot of powder residue and carbon inside the bolt carrier and the problem went away after I cleaned inside the carrier and behind the bolt.
Colt have a lifetime warranty and I would suggest contacting Colt customer service at the factory and tell them about the problem so they could fix it.