I'm curious about this myself...I hunt with a .300 Winchester, killed white tails, mule deer, and an elk with it...but bought a .338 for elk/moose. The .338 I bought didn't give me the accuracy I wanted, so I just continued using the .300, but I still have an itch for a .338, even though from what I've read, you really can't tell the difference between the 2 on game.
So- can anyone here tell the difference on elk/moose/bear with the .300 vs .338? Is penetration similar using the "standard" 180-grain .300 against the 250-grain .338 Winchester? I would say the .338 with 250's should give more penetration given from what I've read, but I've never tested them out myself, but that's worth exactly what I paid for the advice...nothing!
Didn't read thru all the posts, so this may be redundant. Short answer is NO.
The GAME (NA, anyway- all I have experience with) can't tell a bit of difference from .243 to .375 as far as I can tell, properly hit. This is based on something over 100 head (a piddling amount compared to some posters here) of BG animals killed with everything from .243 to .375, whitetail to moose. The moose double-lunged at 70-80 yards with .243 100 gr. C&C went about 20 yards. One moose quartering one-lung hit with a .30-06 180 gr. at 160 yards (my longest shot ever on 20+ moose) went about 100 yards. An elk hit with 140 gr. .260 bullet was bang-flop. Neck spine shattered. Several caribou double lunged with the same .260 loads beyond 300 yards also bang-flopped or almost. One or two seconds thinking about it doesn't count.... A caribou double lunged with .30-06 150 gr at 300 yards two years ago went 120-150 yards all told, out and back, dying within yards of where first shot. A second caribou at 433 yards less than a minute after the first one went down, similarily hit, went about 5 yards. These were 150 gr factory loads leaving the muzzle at an advertised 1080 fps.Hornady SuperPerformance factory loads.
Be it noted one will frequently not get a bang flop on moose without a CNS or large bone hit. It can take a bit of time for the lungs to fill up and/or the blood pressure to drop enough for the tip-over. I had a yearling (running at 35 yards), make about 100 yards after I neatly centered a large artery just under his spine with a 12 guage slug immediately behind the shoulder. His meat was durn near white- very pale, anyway. Best eater I've ever had. I missed. I was trying for the spine, since he was between the boat and me, on the trail when I fired..
I don't have a .300, but do have several .30-06s, and one .338WM. I can't tell the difference in "killing power" between them, no matter what loads I use. More importantly, neither can the game. The .300WM is an excellent compromise (I hate to use that word in this context) between them. You are fine with it- you don't need a .338 for anything in NA. You might WANT one for brown/griz bear, but don't really need one. It's why I got mine, as I hunt moose in thick cover, and those 2 gallon piles of steaming bear chit were a bit unsettling. I haven't fired the .338 in 8 years.....
. I'm hoping to take my next moose with the .260, but not this year - I've only an '06 up here.
I almost never recover a bullet from any caliber, with any load, - unless it hits bone. Then only sometimes, or it is so badly fragmented as to not count. I simply do not worry about "penetration" unless a BULLET proves itself deficient - and I've largely gone back to C&C anyway, which have proven sufficient for most of what i do.
I have only had one bullet fail to penetrate sufficiently to kill the animal. The one that blew up on the shoulder blade of a moose at 100 yards was a Nosler Partition 210 gr. from the .338. First and last animal I ever shot with that load, tho the second one up the nose (more or less) at 10 feet did the job. I prefer not getting that close to a wounded animal, before it lurches it's way back to its feet.... I now usually use an insurance shot from a few yards out.
I used some '06 Federal Hi-Shok (I think they were called) that expanded and separated immediately on a sheep at 330 yards, and a moose 4 days later at 70 yards. They killed but I didn't like the bullet separation an inch or so under the near hide. The moose didn't need the second shot, and possibly not the sheep (shot placement was too high, just under the spine, paralyzing hind legs). Most accurate ammo I ever had for that rifle, however, but no good for hunting anything larger than coyotes, IMO.
Those are the only two loads I have ever found "deficient" and won't ever use again, providing the load is matched to the use. Caliber is down the list a ways... Mostly what I choose to use nowdays is the gun I feel like hunting with, and caliber is secondary.
