I've loaded 40s in the past but it's been awhile and were just run of the mill 40s. I have a Glock 40 (10mm long slide) that a bought a KKM 40mm barrel for a while back. It shoots standard 40s just fine but are pretty anemic. I'd like to load some hot 40 about as close to 10s as I can get safely. The gun is obviously designed for 10mm pressures but of course the 40 case has much less volume so there's that. Anyone played with max 40 loads in fairly strong guns? Yes I still have the 10mm barrel but I don't have much 10mm brass. 40 brass I have.