It feeds reliably - Hornady Critical Defense .380 ACP 90 Grain Flex Tip eXpanding Centerfire Pistol Ammunition

If you are having any feeding issues with a Glock 42 (or any of the other smaller .380's), especially with hollow points / carry / defense ammo, give this a try. It has a more rounded nose, giving it a smoother feed from magazine to ramp to chamber. Goes bang every time, and is accurate to point of aim. I've not personally done gel tests, but the ones I've seen demonstrate that this ammo performs admirably and as designed. Good price, good delivery time as well.