I guess that is my pet peeve. "Marginal." I cannot for the life of me understand why sooooo many people want to take deer at the greatest possible distance with the smallest possible dose. I traded my 6mm model 7 for a .308 M77-MKII and never looked back. Sure, the 6mm does kill deer, but I'm sorry, the .308 does a much better job of it. I have lots of rifles, large and small calibers, and I use nothing smaller than 7mm-08 on deer. I don't own any .25 cal. rifles, but I'm sure I would use them on whitetails if I did, but I wouldn't go smaller than that. Where I live and hunt, the 7 mm-08, .30-30, .30-06, and .45-70 take deer and larger. The .22-250, .357, and .22 in addition to shotguns take care of the rest. The 6mm or .243 Just doesn't do anything I can't with the others. IMHO the 7mm-08 will do everything a .243 will do.....but much better.