I bought my first AR from a freind. It is a Colt carbine with a lower marked Match HBAR and Sporter. I’m not sure how old it is but I believe it dates from the ban era. From my reading of past posts this lower may have non-mil spec pin diameters. The rest is all Colt as well. This carbine just runs well with all ammo tried. Is there any thing else I should know about these Colt lowers? Roll markings aren’t important to me.
Thanks
if it is a post -ban it will have a screw type take down on the front pin instead of the push type,
a sear block in it marked with colt on top of it so you can’t use a full auto bolt carrier just the semi auto one that is cut out.
Also the FCG pins would be of the larger type ,Colt did this so you could not put M-16 FCG in them.
but have since stopped doing that .it is still well made and GTG .just get you a extra FCG as a back up they are still around .and shoot the hell out of it
That is not a defining feature of a post ban Colt.
Both pre and post ban guns have the screw type takedown pin.
The OPs gun is pre ban. It is marked Sporter. All old AR-15s marked Sporter are pre ban.
Cool thanks for clearing that up for me. I do remember now a Colt preban sporter I bought in 92 have the crappy screw take down too. I am losing my Memory 
Thanks to all who responded, I appreciate the information. Which leads me to ask another question: Is the upper to my lower proprietary? It does have the screw in type hinge pin. Will my upper work on a standard lower?
Thanks
If your upper has a small pin (0.250") pivot hole it will work on any normal lower.