Just finished fitting a 38 Super barrel to my 9mm Rock Island 9mm. Taking it to the range today to test it with Aguila 130 gr +P loads. Barrel was pretty much drop in. The most work was installing the barrel link. everything seems to be locking up tightly and rounds feed and extract nicely. Currently using one Taurus 9mm magazine that has a plastic spacer for 9mm that I've removed for the Super rounds.