GFF, It seems to be random
Ronmar, I'm seeing this issue only with the Thermold Magazines. If I use the Metal Magazine supplied by Kel Tec I'm not seeing any problem.
As far as the ammo, they are my Hand Loads. 168gr HPBT bullets loaded into Lake City 7.65x51 Brass. OAL of 2.800" with 42.5gr of Ramshot TAC powder.
I also bought some factory Winchester 145gr ammo and I'm still having the same feeding issues with the Thermold Mags. I did verify that I bought the Metric Versions.
I tried loading just 19 rounds to see if that fixed the issue, no luck.
Also this rifle has about 300 rounds through it.