I've done it in 9 with 7gr of 3n38. Plated bullets are fine, can't really push a 147 fast enough to strip them. If I had to do it in 38 I would say start about 6.8gr of 3n38 and work up slowly watching for pressure.
Ok figured it out. A little bit of forward rotation on the draw was causing the sliding part to pinch and not slide away from the trigger guard as it was puled out. Popped the side plate off and added more tension to the screw / spring and it works perfect.
Recently switched guns and the new gun has a PT Evo grip. The holster is made for the STI grip. I filed the holster to fit the evo grip, and it fits and works perfectly when going slow. At speed it hits a snag most of the time just as it should release. I do not see any marks or hard edges to cause the catch, kind of lost.
K.C. shoots 147 major but he is the only one I know of shooting it with regularity. I've loaded some up to play with after talking to him about it. I used plated bullets but coated should be roughly the same. 7.0gr of 3n38, 147 plated HP, CCI SR primer @ 1.165OAL. Avg velocity for me was around 1170fps. Recoil pulse and sound is different for sure but very soft in the hand. 5" barrel with 3 small holes.
One of the guys on our squad actually shot the cable splitting it in two, which caused a mike on one of the swingers. He did not get a reshoot, which IMO was the wrong call.
YMMV, I've loaded 147's over 7.0gr of 3n38 @ 1.165"OAL for an experimental open load. Avg velocity was around 1160fps out of a 5" KKM barrel with 3 ports.
I shot the xtreme 165's for 2 years before making the jump to open. 2.8gr of titegroup at 1.140" yielded 130pf, very light recoil and acceptable accuracy.