[Erno86]

Not an expert...but I'd keep the chamber and bore free of oil before you shoot, buy running a patch of degreaser down the bore with a rod, and also fire a fouler shot, to make sure all the oil is gone out of the bore; before an accurate range test. A very light film of oil in the chamber should not hurt --- but might affect accuracy; and proper fireforming of the cartridge if it is a lot of oil in the chamber.

I've not heard good stories about Rem-Oil, with the product being compared to "gummy" WD-40. I prefer a half synthetic motor oil for lube jobs on a firearm.

I use a steel chamber bore brush and rod soaked with degreaser {rotate 12 times} then clean out with a chamber mop or a cloth patch; after each shooting session. You still might have new machine marks in the outside chamber lug fin entrance in your new rifle --- Chamber bore brush rotation might solve the problem.

I prefer to have my trigger group oily...with the inside base of the receiver --- below the trigger group --- coated with a film of oil. This will give a chance for any blown primers to stick to the bottom of the receiver ---instead of in the trigger group --- which would cause a jam.

The AR's bolt carrier has two oil key holes, so you can lube the bolt. Otherwise...just keep the bolt oily, with no oil on the face of the bolt or inside the firing pin housing before going on a critical mission; unless the primers are sealed.

Keep the front of the bolt carrier lubed...with the rear half of the outside bolt carrier dry --- because you should keep the recoil spring from being soaked with oil.