IME 140-160 gr bullets out of a 7mm rem mag have performed flawless and I actually couldn't ask for anything more. As long as you pick the right bullet for the job the grain size in most cases falls into a personal preference area more than a requirement. I have a hard time swallowing a 175 TBBC would work/perform any better than 160 NP or similar on elk, just my opinion based on experience.