My sons Mark IV doesn’t like Aguilar or CCI Minimags. So far that’s all he has shot thru it and it jams every now and then. I thought about maybe polishing the feed ramp, but don’t want to make it worse.
I find the Aguila Super Extra in the bulk box to be very waxy and sticky. Often have failure to feed problems, especially the first two rounds of a full 10 round magazine; exactly what you experienced in your first trial. They seem to run fine out of the rotary magazines on my 10/22 sportster. I think they are just too sticky to slide smoothly out a Mark IV magazine with full spring pressure. Had you run that test with just 5 rounds, like you did with the other ammo’s, I think it would have fed fine.
Fiocchi is manufactured by CCI just put in a different box. This was good for a function test but for accuracy I would have wanted t see 5 five shot groups of each. Norma Tac is RWS.
