KenMI wrote:Barnes does make 2 different 275 grain bullets. One is the XPB with 3 grooves. The other is the TSX with 2 grooves. Not sure if the hollow point is different, or if the expansion velocity ranges are the same or not. Barnes certainly would be happy to let you know, if you contact them. I know many guys use the XPB version, and their site says the TSX version is for the 450 Bushmaster. Probably does not make a bit of difference really. The 3rd groove might help slightly with copper fouling, but I have zero issues with fouling with the T-EZ bullets with no grooves, so that might not even be a factor either.
From Barnes, the 275 TSX opens at 1200fps in water tests, the 275 XPB opens at 1400fps. I also asked why the TSX is undersized (.4500-.4505) and they said that it will help reduce pressures (for same load) without losing accuracy. I don't know what the 275 XPB diameter actually is, but I get slightly better accuracy with 200 XPB's compared to the 275 TSX's, and the 200 XPB's are slightly bigger (.4510 I believe). With that said, I still get good accuracy from the 275 TSX's. I also run them a little harder and sacrifice a little accuracy because I haven't needed a 100yd shot on game.