I have a Sig 1911 stainless and 5 sig factory mags. My problem that I am experiencing is that when the slide locks open after an empty mag, I drop the expended mag and TAP in the fresh mag. What happens is the new loaded mag goes in too far and blocks the slide from going into battery. I was always taught to tap the new mag in, as I do with my Glocks (with no problems).
The Sig mags have a rubber bottom and I can't see if they have the metal shoe toward the front like regular 1911 mags. I look on forums for any input on this but can't find anything. I really don't want to send the pistol back to Sig as it is my favorite EDC.
Any ideas anyone?

Please explain “tap the mag in”.

What happens when you tap in an empty mag? Does it still block the slide from closing?

My wild ass guess is that a fully loaded magazine is holding the slide back and the tightness of the fully loaded mag keeps the slide from closing.

IF an empty mag doesn't hold the slide back when released try down loading the loaded mag by one and try it, then down load by two and try it.

Also when you have the mag fully loaded try pushing down on the top rd and see how far the rds will go down. If its next to none then the new mag springs are so tight and lack of excess room in a loaded mag may be keeping the slide from picking up a rd and closing the slide.

Insert mag, tap to make sure it is seated. This is common procedure taught by most instructors.

I have not tried an empty mag but will do so. All my factory mags work fine as long as the slide is closed on insertion. It is when the slide is locked back after ring a full mag that the new full mag goes in too far. Like the stop for the insertion is not working correctly.