Re: .223 bullet
I contacted Barnes after i couldnt get the 53gr TSX to group from my a-bolt in 22-250, with a 14 twist they recommend a 45gr tsx. I rev them up to about 3800 fps and they are a deer killer and shoot very good with my 14 twist. Barnes bullets are copper so all bets are off from what we usually know about twist -vs- bullet weight and even with a 45fr tsx HP i get complete pass thru with a great wound channel.
It may be a poor choice of words but I am smart enough to understand what you meant.