Other information on this subject is posted on the Remington Announcement thread. I started this thread to keep loading information in an accessible place. Maybe someone can move over the appropriate posts.
Over the last couple of weeks, I shot some of the resized 250 gr. Barnes 45-70 bullets (.458) to .452. For a load I used 37 grs if LG with a WSR primer (close to Hornady max). Cartridges were loaded to an overall length of 2.23 inches and taper crimped. This bullet has a very large hollow point opening and reliable feeding will only be thru the Bushmaster supplied magazines. Sigs and Magpuls do not position the bullet high enough on the ramp of the AR and usually the last round will hang up.
Velocities of the load (I only shot 4 thru the chrono - 16 inch barrel)
1. 2279 fps
2. 2306 fps
3. 2302 fps
4. 2267 fps
Av -- 2288
ES -- 39
Sd -- 18
Accuracy was 1 1/2" at 100 yards.
This test was just to show that you can resize these solid Barnes bullets and they will shoot OK. This bullet would not be my choice because of its poor BC, but it could be used. At 300 yards, the Hornady 250 gr FXT has the same energy and velocity as this Barnes bullets does at 200.
These are some pictures of the recovered bullets. Berm as frozen (11 degree) and most of the time Barnes bullets do not expand in soil anyway. They rely on hydraulic action. Note the rifling impression and the grooves. The bands are very, very close to the 450B bore diameter. Within the working zone.