I've shot most of the mentioned powders through my 7mm-08, and a number that have't been mentioned. RL-15 at 42.0gr under a 140gr Bullet is my #2, but IMR4350 just can't be beat. I prefer the Remington 140gr Corlokt for general use, and 140gr Partition for "special occasions". I haven't ever gotten the accuracy or velocities claimed for Varget, so I'm not a big fan of it. I prefered H380 for accuracy with the 150's. But, IMR4350 beat it by 100fps and near equal accuracy. See Lyman's #48 for more data. Their results most closely match mine, of the manuals I have.
For lighter game, use either the Remington 140gr Corlokt Soft Pt. or your choice of either the Sierra or Hornady 140gr BTSP. I bought 500 of the Remington's after I tried the first 100, essentially a "lifetime supply". A gunsmith friend of mine recommended these. He's gotten under MOA at 1,000yds from a 7mmWSM benchrest rifle he built and shoots in competition. He uses it for every thing "except" competition in various 7mm's.
For heavier game up to ELK, use the Nosler 140gr Partition (in spite of what my gunsmith friend say's!).
Another friend used my 7mm-08 last Oct (2005) to shoot a weighed 1,200lb elk 6x6. The Nosler 140gr Part. completely peneterated! A single 140gr Sierra BTSP (I told him to use these only for checking the sights once in camp, but he's not too gun savy and did't pay attention- reason I loaned him the "little 7".) was just under the hide on the far side. The guide told him to shoot a second time, even though the elk stood in place and was weaving, about to fall down. At second shot, it did!
For Moose, or incidental great-bear, I'd probably use a Nosler 160gr Part. Load this over 45.0gr of IMR4350. I prefer Fed.#210 Primers.
Because of the modest case capacity, and loss of 100-200fps with the Barne's solids (X and Triple-shok), I prefer to use the Nosler's.
Proven performace and easily duplicated.
I've found the factory equivalent powder of H414/Win760 is unbeatable for velocity. My 20" bbl gets 2,860fps with 48.0gr of Either.
But, velocity is near equal, and accuracy tops with IMR-4350 at 48.0gr. 50.0gr is "doable" with either the Sierra 140gr BTSP or Hornady 140gr BTSP, but with "longer bearing surface" of Non-Boat-tail bullets, 48.0gr is better and in mine, and several other friends rifles has failed to show pressure signs even in early seasons here where temps can reach 90deg in afternoon. I've found similar experiences to that of John Barsness of Handloader Magazine in this regard.
I've really enjoyed my 7mm-08, and it (Remington Mod-7 w/laminated stock and 20" bbl) is my favorite of all my rifles. (Don't tell the guys over at Marlintalk.com I said so !!!).
Point and Click, dead game POA/POI to ~300yds. (I sight in for 250yds w/3" high at 100yds).
I had "resisted" trying this cartridge for many years. However, an aquaintaince who had used an early Remington M700V to shoot metallic shilouttes and had "cropped" over 2,000 deer with his, continued to persist in suggesting I try one. (he uses 48.0gr IMR4350 and Sierra 140gr BTSP for ALL his shooting).
Glad I finally did.
Mr. and Mrs. Jack O'Conner were right after all!
(7mm08 essentially duplicates max handloads in the 7x57 or if you have a british rifle, 275 Rigby).