agingcowboy said:
My 1st 100 rounds through this rifle were Winchester BSTs. I then shot probably 50 rounds of different stuff until i settled on the Hornady Precision Hunter (ELDX). I bought 30 boxes of it at the same time (ordered online through Midway USA) and have been shooting through it over the years. I'll have to check the lot numbers but I haven't bought any new since the initial purchase.
I wish I knew more about hand loading, but I've never gotten into it. I'm still trying to wrap my head around some of these details. I will at least get a new box of different ammo and give that a try and see if things tighten up.
When you checked your scope mounts a while back, did you actually take the scope rings off the bases and check the bases?
I would take out the action from the stock. Make sure no little pieces of debris got in there. Grass seed, sand, whatever can get in there and cause issues. Blow out the inletting with compressed air. I would put it back in, being cognizant of how you tighten the action screws, and see if you hear anything odd as the action goes back into the stock.
Make SURE that the internal mag box, if it has one, is able to move slightly. If it binds it can cause stress in the action as you screw the action into the stock.
Make sure that your action screws are torqued properly.
Check the bases without the scope on the rifle. Take the rings off. Check every base screw.
Check the rings. Every screw.
Take off the brake and see if their is any damage to the crown of the barrel. I know that is a slight possibility, but just check while you're going through this other crap.
While you have the scope off put another, proven scope on it and try that. It very easily can be the scope. NF is great, but everyone makes a lemon.
Also, when you shoot, do you shoot with a rear bag? If so, make sure the sling swivel isn't sitting on the bag. The rear sling swivel can make your rifle act schizophrenic if it's sitting on the bag weird. I know that sounds crazy, but I've seen it.
For what it's worth, I've been having great luck with the KG cleaning products. There's a review from a guy named Corey (from MidwayUSA) on their KG-2 Bore Polish who details his cleaning procedure:
"KG two-step: Punch through their carbon cleaner as directed, then about 20 one way passes with this stuff on a patch wrapped around a nylon brush...blow some carb cleaner (ooh-rah) down and clean patch till dry. What this does is remove all carbon and the copper along the inside of the barrel. What it doesn't do is remove all the copper from the little imperfections that usually have to get laid down by your fowling shots."
I've started doing this when I clean and it's been effective for me. But I don't clean very often. My 308 has 80 rounds fired through it since last (first) cleaning @ 52 rounds. That's not a ton, but my last 2 5 shots groups have gone sub 0.500" @ 100 yards.
My 300 WM has 173 rounds since last cleaning in 2015 and the last three shot group @ 100 yards went 0.630".
Most guns like at least a little fouling to shoot their best. If a rifle only shoots accurately only when it's super clean, get the hell rid of it. You want to shoot, not clean.