I just picked up a 10 round McCormick power mag and ran into an issue.

I have a SA Loaded that I've been using Hornady XTP rounds in. I've been using the two mags that came with the pistol and I haven't had any feed issues.
The McCormick mag does not want to feed the XTP into the chamber with a full mag. If I only load it to 8, they feed fine. But 10 rounds and it just slams the round into the feed ramp. It actually caused the round to set back into the casing.
I loaded some Critical Defense and regular FMJ into the mag and it feeds fine.

I'm assuming it's due to the somewhat flat nose of the XTP round compared to the other two. But I'm wondering if it would do the same to another HP round, like Gold Dots or HST.

The 10rnd won't be a primary carry mag, but I would like to be able to shoot the same rounds out of it that I carry.

Any thoughts other than to just buy some different rounds to try? Anyone have luck feeding GD or HST with the 10rnd?

Best bet is going to be with a Remington Golden Saber.  They feed about as good as ball.

10 round mags are touchy, especially if your ramp is a little steep and/or you mag catch is low.  It just exacerbates the natural problem of a ten round single stack.

I have had good luck with the CM 10 round mags, and 200 gr GD'S.   I woul recomend changing out the springs though. I put thw Wolf 10% springs in all my 1911 mags and I think they are the key.

Put a Golden Saber as your first round and Gold Dots as the rest. I do that in mine and everything feeds fine.