I put about 120 9mm rounds through it (0 problems) after shooting 50 rounds of 40. I can't say that it's more accurate with the looser 9mm barrel, but I'm more accurate with it in 9mm, a lot.

Call me Flinchy McFlinchy.

If it tests out reliable with SD ammo, I don't see why you couldn't carry it with the 9mm barrel with confidence.