I have a couple of the circle 1 mags, what is the significance of them?
Circle with 1 mags are probably the least produced of the Colt marked. Nothing fabulous but they are worth a couple bucks more each. Don't think Colt ever made mags but they have them contracted by others and put their roll mark on them. The ones without the 1 in the circle, just the circle or upside down marked 1 (basically blems), are more rare but there are many who just collect the different mags. Kind of a hobby thing. Only the waffle mags have any real value unless it was a quick couple but I've only seen pics of those. The standard 20 rd with Armalite/Colt floorplate are kinda rare also. The floor plate and follower having the real value. Most will trade or pay a little extra for the ones with the circle.