I could drive you nut's with questions right now.
Looking at your photo's, it appears that most of these rifles come in between maybe 9 lbs to maybe 15 lbs? I suppose that is because everything must be carried by the shooter for the full 2 miles? Then reading thru the rules, I saw no mention of a weight limit.
This seems like a very good course for people with hunting weight rifles to really learn better field shooting. Oh yea. I also am noticing that there are a relative few fluted barrels. Due to shot's being spred out so far that heating not a big problem? Also seems like Remington, Savage and something with a winchester saftey and a square block of a bolt shroud are the rifles of choice. Noticed only a few auto loaders. Don't intrest me anyway.