1911 Malfunctions
In the first photo, the slide stop appears to be slightly out of parrallel with the frame, by less than a mm. Also, the slide stop appears to have too much material on the lug. Other causes could be inadequate slide stop plunger tension or a bad magazine (yea, I know, lots of folks like to blame the magazine for nearly all 1911 problems).
With the factory loads you are shooting, there is no reason to be changing the stock recoil spring, or to use a shock buffer, or anything other than the stock guide rod. Save those mods for bullseye shooting when you are shooting wadcutters and reduced loads.
Failures to feed could be bad ammo, rough feed ramp, bad extractor, bad magazine or bad magazine spring. Start with the ammo, eliminate that as a problem, then look for a rough feed ramp. With ball ammo this is less a problem than with wadcutters. Finally, number your magazines and note which one is being used when there is a failure to feed. Swap the spring, but not the follower with a known good spring. As you move the magazine parts around you can eventually determine if it is magazine frame, the spring or follower. Keep written notes about magazine number, first round, last round, type of ammo. Be methodical and don't let the bench shooters point you in different directions, like "use only Wilson mags", or change to a lighter/heavier recoil spring. You will get the problem solved sooner and for less money.
Once you eliminate or correct problems with the 1911 and ammo, if problems continue, there's not much left except what is attached to the grip.
