no you will not have a gap depending on who makes the mag it may have the shorter follower or it may have a Bumper type base on the mag

Roger, no Sir it will not. It will also fit flush as it is the same size with slightly shorter follower legs to accommodate the 10th round. Cheers and stay safe!

Hi,
Most of the Colt Competition 1911 10rd mag comes with a baseplate that hides the gap, so it depends on whether the mag you order have this baseplate or not. Check here (https://dawsonprecision.com/dawson-precision-9mm-10-round-competition-ready-magazine-kit/). I hope this helps.