Hi, I am new here and like the set up.  You guys are knowledgeable.  I recently acquired a Colt preban Blue Label.  I know that they need special pins to use other uppers.  My question is, is there any manufactures out there that come close to the Colt finish?  It is the fenced model.  I would like to get a 16" upper that matches the lower or at leadt real close.  Also, I was wondering if the front sight could be replaced with a bayo luged one?  

Thanks for the help and any information.
jlittle

I was also wondering ther same thing. Bought a pre ban sporter in Nov of 93 and am also looking to get an M4gery upper. I think there are pin adapters that would make wide pins fit narrow lowers and vice versa. I saw on a thread that you'll find many variations in Colt's pre bans because they used everything they had lying around.