I’m having consistent issues with failure to feed and/or failure to lock back on last round.  It’s not magazine or ammo specific.  350 rounds fired and it’s not improving.  Any suggestions?

Full size 9mm 1911's can have a 10lb recoil spring for target ammo and a 12 lb for hotter hollowpoint ammo.
Start there and make sure the recoil spring is correct for the gun.

Next step is correct extractor tension.

What grain ammo are you using? Mine tends to prefer 124grs or heavy bullets. If I’m shooting 115gr ammo I get stove pipes or failures to lock back especially on a lighter load.  I’ve also noticed you gotta have a good hold on it, no limp wristing at all or the slide doesn’t completely cycle.

It does it with 124 grain as well as 115.  Once I had difficulty pulling the slide back to extract an unfired round (failure to go into battery?).  I don't know the spring weight, it's a new pistol and it's what springfield put on it.  

I definitely wouldn't trust my life with this pistol.  How do I determine what spring is on it?  I believe these are symptoms of short stroking?  I want to love this pistol,  but can't in it's current state.

Alrighty then

Contact me at [email protected]

I will get you helped out.  Just note, I will be out of the office starting NOv. 24th for 10 days on an Elk hunt.

You can also contact [email protected]

The 1911 9mm’s come with a 9lb recoil spring.