I'm forced to shoot a lead free bullet out of my 257 roberts and decided the barnes TTSX's would be a good place to start. I shoot a m77 with a 20 inch barrel and for 25 years have shot sierra 120 grain hpbt's at 2700 fps. 400 yards is about MY limit and this combo has always worked fine, when I do my part.
I tried the 100 grain TTSX the other day and accuracy was great but could only produce about 2800 fps, with a few different powders before I got pressure indicators in my rifle. Is 2800 going to be enough to reliably open up the 100 grain at 400 yards or would I do better at 400 pushing an 80 grain at maybe 2950? The copper bullet is brand new to me so any real world insight would be appreciated.
