Check the barrel feed ramp very carefully after thoroughly cleaning it.

I was getting several FTFs until I noticed two tiny black dots on the ramp. I used a dremel and polished them off. I figured they were some errant bluing since solvents didn't remove them.

Since the ramp was polished, I have put through 1500 rounds without a single FTF and I've tried CCI mini mags, Walmart Federal 550 bulk and Federal 525 bulk.