I re-bedded My RPR a week ago. I had previously done the foil bedding, in my case using the tin foil from a small pie tin. Perhaps over time the bedding had become compressed, as the magazine block was loose again when I took the action out. This time I bedded it with the tin from a pop can, which is just a tad thicker, and everything was firmly in place. I also bedded what I'm going to call the "recoil lugs." Cut into each side of the barrel, near it's end, are two "U" shaped mortices. When the barrel is installed back into the action, these mortices fit into two plastic lugs molded into the sides of the action. The are probably there so the barrel is properly indexed when placed back into the action. I measured the size of the mortices and lugs that fit into them and there was a sizable gap. I cut two thin shims of aluminum to take up some of this gap, and using a couple of drops of superglue, glued the shims over the top and side of the shims. When I put the action back into the stock, I could feel kind of a "pop" when it went into place, so now I feel everything is more secured into place.
I took it out to the range and the first 5 rounds all landed into a 1/4'' square at 50 yards. But my next few groups opened up again; I'd get three or four rounds in a tight group with the all to often flyer, and then a tight group again. The more I shot, the more the groups opened. I was shooting SK rifle match of a bipod and rear bag from a bench. The temps were in the low 90's, and sunny. While I and the action was in the shade, about 1/2 the barrel was in the sun. When I reloaded I would place a towel over the scope and barrel to keep the sun off of them. The guy next to me had a digital inferred thermometer and I had him read the temps on the action (88 degrees), and then the end of the barrel, the part out in the sun, (118 degrees). I stopped shooting and went home.
Last week I went to the range again. The temps were in the 70's and overcast. I shot SK pistol match at 50 yards and again got pretty respectful groups, the occasional 1/4," and 3/4" groups, with the more usual 1/2." Was still getting the flyers. Once I felt the cleaned barrel was getting settled in, I began adjusting the action screws. At 30 inch pounds the groups were two inches high and as much as two inches in diameter. I found that the lighter I torqued the screws, the tighter my groups were. I've got my action screws set under 18 inch pounds now. I use Butler Creek "hot Lips" 25 round magazines, and noticed that I had a few problems with loading and ejection when I had higher torque values. Lowering those values and the bolt cycles a lot smoother with no problems.
My rifle is basically stock, and I'm trying to decide if I should buy a Shaw barrel. What I have noticed, but can't prove, is that the factory barrel has a "Sporting" chamber, which is large enough so the rifle will shoot anything .22LR. But accuracy suffers because of this. I get my best groups when I have the dreaded "carbon ring" in the chamber, as I think this helps keep the bullet aligned in the chamber. There's a sweet spot in the size of the carbon ring; too little and the base of the bullet isn't supported, too much and it scrapes the side of the bullet, and it's no longer aligned square to the bore. A match barrel with it's tighter chamber and engraving the bullet into the rifling will align the bullet. In this case the build up of a carbon ring isn't wanted at all.
I've also noticed that ambient temperatures seem to effect accuracy. I have a harder time getting good groups when the temps get into the 80's or higher. Perhaps the higher environmental temperatures are outside of my personal comfort level. I shoot a 25 round mag, 5 shoots per target, and probably too fast, so I think chamber temperatures have some effect. I've noticed that during a long string of shots, if I chamber a round and wait for the wind to calm, that shot is normally a flyer. I now leave the chamber open until I'm ready to shoot, and I set a cadence to when I fire.
I've had the rifle for about two years. From it's serial number, it was built in the first month of production. I've got over 8,000 rounds though it. Despite all of the things I've had to do to it in an effort to improve it, I've enjoyed it immensely. But then, I like doing things like that. For the person who doesn't have the patience to work on it, it may not be the rifle for them.
This has just been some ramblings with my experience with the RPR while I'm avoiding doing yard work.
