I carry mine Cocked n Locked just like my 1911s. The Browning and MecGar mags will work in it but I like the MecGars better. They have both 13 and 15 round flush fitting mags for the HP and both work well. I put a set of slim wood grips on my MKIII but found the magazine partially ejected a couple times while carrying it so I put the original Pachmeyers, which I don't like, back on it and have had no further issues since they stick out farther than the mag release button.