I shot a 7mm TCU, which is an improved 7mm on a 223 case I a 10” Contender for pistol silhouette in the 70’s until ‘85.
Even out of the 10” barrel I’d consider that an adequate whitetail cartridge. That was a popular cartridge/pistol combination then. I have not shot pistol silhouette since then.

I prefer classic.
Semper Fi
I used to run with the hare. Now I'm envious of the tortoise and I do my own stunts but rarely intentionally