11.25 Twist is the same as the Remington 700 5R which I had one in a 20incher. Although it wasn't a Gas Gun and certainly NOT A GAP but it Loved 175 SMKs Way More than the 168s Especially at Longer Ranges. My understanding is Both the 155 and 175 SMKs outperform the 168 at distances. I think there was a post by LONEWOLFUSMC on this subject once but I can't recall what the title was.
In summary, I think you'll be just fine shooting 175s and they should be A LOT HARDER TO FIND these days. So if it's a good source, I'd appreciate it if you can share so I can get some too...LOL
Cheers.
HOG.