Just got home and it's dark now so I'll try to answer what I can. I did pick up some factory rounds after work so I'll try them tomorrow.
I have loaded a single round and 2-3 rounds. Doesn't hold the bolt back with one round and with single or multiple in the mag it doesn't eject the first round so no chance of picking up a second. I'm a simpleton reloader and weigh out every charge on a balance beam scale. Just before I posted this I sprayed down the action good with rem-oil hoping to get better results but same. I'll post some more tomorrow on how the factory loads shoot and where they fall. The questions on the gas block size and stuff is over my head so I'll need to look up how to determine those.