GOF has the best advice, weak hand is learning shooting all over again. As others have encouraged, plan on burning 70% practice ammo for weak hand. You won't fight the sights as much.
1960s standard issue side arm was a 38Spl, 5 shots with one make up round. Steel Challenge was an LEO training aid and still should be. Minutia: IPSC/USUSPA and Steel Challenge all started in Fawnskin, north side of Big Bear lake.
Apply pressure to the base pad, then cycle slide. If it works, it's the mag release or the position in the frame.
edit: if the mag is too low in the frame, the bullet transition will be held back by the mag lips.
Fast burn powders are not meant for ham handed reloading. It's fast for a reason, don't expect AA7 forgiveness. If Betty Crocker sez only this much baking soda, experimentation on your part may not be good for the oven.
Nothing replaces actual firearm practice, but airsoft isn't a bad alternative. Good friend has a steel challenge course in his garage. Uses garden netting behind the plates to catch and collect the 6mm BBs.
I use clays for 9, 40 & 45. Nothing wrong with trying new powders, but my 8lb jug still has a few lbs left.
98, talk with your squad members. There's ready info on the hoof.
Low pressure loads don't fully expand the case against the barrel chamber. Think blow by. If your load cycles, feeds and hits where ya aim you're way ahead of a lot of people. Worry about minutia when it affects score.