If it concerns you.. I would spray the whole thing down with gun scrubber.. preferrably before assembling, but you should be ok. Gun Scrubber is almost like brake cleaner just a little less harsh, you use that to remove the packing oil off of disc rotors for cars so I would do the same process. Then make sure you oil it very well and cycle the bolt several hundred times. I literally drench my bolt and work it in really good before firing, that allows the two to get know one another very well. With that being said, enjoy your new toy and keep em straight!!