Just to use Art's "muddle the whole thing up" train of thought ...
The M7's got a 18.5" bbl & I've not garnered much in the way of velocity out of it. Haven't played all that much with various powders but do get an honest 2400fps with 165s with what I do use. It works for me.
Doing the ballistic program, it'll still do all but 1700 ft lbs of energy at 300 yds & that's plenty for elk with proper placement & bullet. Sighted dead on at 200, it's about 12-14" low at 300 though. Depending upon your scope, the subtention at the lower duplex will take care of that rather nicely -if you know the range.
I hunt dark timber mostly for elk & have taken several at 15-25 yds so that hardly matters.
Shot an elk with a Barnes .308 165 XBT (honest 2400 fps) at about 15 yards. A spike, walking away. Hit in the rump, broke through pelvis, skipped off of two ribs & back into chest & then out the sternum. Bullet was not recover because it wasn't in the elk any more.
Only big game critter I have ever seen that did drop right in its tracks. I have dropped them within 10' or so but never "in its tracks."
Very minimal meat damage (= almost none) & figured about 5 FEET of penetration & that after breaking (initially) a very major bone.
Doubtful that you'll ever get blazing velocities with big game weight bullets, but that really isn't neccessary.
Everything in the world has been killed with a 200gr bullet at 2100fps.
Wish I would have hooked The Wife up with a .308 rather than 7-08. Was a little concerned about recoil (needlessly) intially.
But still, the 7's nothing to sneeze at & just about everything's been killed with the 7mm Mauser & the "li'l 7" is the same thing but only in a smaller package.
With the way she shoots, I have no doubt that she's not undergunned in the least. A 170 premium bullet at a "modest" 2100fps right in the boilerworks will drop anything she wants.
We get a very honest (w/7! fps standard deviation over 10X shots consistantly) & very excellent groups with the 120 Nosler Ballistic tips at 2600 fps in her li'l 7. Nothing blazing by any stretch but a dandy li'l shooter nonetheless.