Re: Vertical stringing
I spoke to a local gunsmith who checked my firing pin protrusion, headspace, and said they all "looked good", however he said that I should not have bedded the first 2" of the barrel forward of the recoil lug, and might be causing my problem. I had seen recommendations go both ways on that issue, so I figured I'd give it a shot.
I took the action out of the stock, (noticing that the action screws were pretty loose) buzzed it out with the dremel tool, reassembled (tightened the action screws had loosened) and went shooting again this weekend. Grouping size at 100 yds didn't improve, in fact they were a bit worse ~3" groups. This time there wasn't really any vertical pattern at all, fairly random.
Not sure if it was the removal of the bedding, tightening of the screws, or the fact that I now have ~30 rounds down the tube without cleaning out the copper fouling.
This is a bit frustrating... At this point my groups aren't any better than when the gun was straight from the factory. Maybe I have a crap barrel? I know the ammo I'm using isn't top notch, but surely it wouldn't be causing that much of an issue at 100 yds.