OP, the twist rate on your T3 is 1-8. I use 48-50 grains of H4831 in mine but also use CCI 250 magnum primers. Yes, the load is stout but I am getting slighter higher velocities with 140 SSTs than you are getting with 129 grain bullets. My rifle is also a T3. I am lucky in that this rifle doesn't seem to mind which bullet weight it shoots. It shoots everything into consistent sub half to 3/4 moa groups or better. I use bullet weights from 95 to 160 grains. These days, mostly Hornady offerings. With H4831, which I use because I still have about a third of a 50 pound keg left from the mid seventies at less than a buck a pound, I found that there was no gain in accuracy or velocity that was recordable after 48 grains and more was a crushed charge. H4831 likes to be packed a bit but not a lot.
Ganderite, I am presently in the process of putting together a long range rifle on a Remington 700 action, with a Jewel 2oz trigger. It has a fluted, straight 1 1/4 in diameter stainless 30 in barrel installed with a 1-8 twist rate and 6.5x55 chamber. It's a Gaillard barrel that I picked up from him a few years ago.
Just out of curiosity, what loading range are you using with RL22??? I've only played with it slightly in my T3 but there hasn't been enough difference between it and H4831 in the shorter T3 barrel to make me want to switch. Accuracy was similar. I only have a couple of pounds of RL22 on hand at this point, but will try to search out more. Also, what twist rate did your barrel have??? A similar Model 70 I have with a sporting contour barrel and in 6.5-06 has a 1-9 1/4 twist in an unknown maker's barrel and it will just stabilize the Hornady 140 grain bullets at around 2800 fps. A few hundred fps slower and groups start to open dramatically at 300 yards. It shoots the lighter 90-129 grain bullets well at all ranges.
Any information you feel inclined to share will be appreciated.
