300 Win Mag vs 338 Win Mag

[daisygordoninc]

I assume most of us have some guns that are not lever guns, so someone may have some knowledge about this.
Why is the 338 Win Mag so much more powerful than the 300 Win Mag which has a larger case volume than the 338
Win Mag. My new Winchester XPR uses the same magazine for both cartridges, I actually have both the 300 and the
338, the 338 in walnut and the 300 in synthetic. No doubt someone has discussed this before.

[crs]

Please explain what you mean by saying "much more powerful".

[Nath]

Please explain what you mean by saying "much more powerful".

Just what I was wondering!

[GunnyMack]

Just looked up a similar load for both, 180 grain bullet, both using IMR 4350
300 WM
Start at 63.0 makes 2787fps Max at 67.0 2918fps
338 WM
Start at 70.5 2848fps Max of 67.0 3038fps

It's not a matter of case it's a matter of amount of powder burned. Burn more then velocity goes up (as does recoil). On another note, the larger dia case tends to give slight velocity increase.

Personally I'm not a fan of 300 WM, but I love the 300 H&H. Also I'm a big fan of .338's, I have a WM on a Mauser and a Ruger Hawkeye in 338 federal.
As for the 300 WM, it's a very good case. Many have looked down upon it because of the short neck...

[daisygordoninc]

So if a 300 Win Mag were fully loaded wouldn't it go as fast as a 338 or faster ?

[daisygordoninc]

I've heard guys say they wouldn't want to shoot a grizzly with a 300 Win Mag, but would have
confidence with a 338 Win Mag, the bullet weight might be the same, or are they assuming
a heavier bullet with the 338 ?

[GunnyMack]

As I showed previously the 338 takes MORE powder which generates higher velocities & energies.
Granted this is one weight of bullet.
The 300 WM is about at it's best with 180-200 grain bullets whereas the 338 can go from 180 up to 250 and maybe 275 grains.

[Deaf Smith]

I've killed white tail deer with both .338 and .300 WM (as well as .223, .243, 30/30, .308, 30-06.) Yes it kills them dead... small wonder.

Anyway the .300 does not kick as much and shoots a bit flatter but the .338 fires a much heavier bullet. The .338 is not a .338 Laupa and I'd prefer the .300 for longer range work.

The best I can say for the .338 is you can go hunt Polar Bear and Moose and when you get to Mule Deer you can load it down in power as they don't need that much to drop them. Just hang on cause when fully loaded it kicks a mite.

Deaf

[jeepnik]

If I were hunting a grizzly I wouldn't be put off using a 30-06. Stopping a full on charge is another story. Much has to do with the state of the bear at the time.

I think the best example was a large-ish black bear I took some time back. The bear had no idea I was there, the shot was well placed and it simply fell over. I imagine had the same bear been jacked up on adrenalin it would have been a different story.

But to the OP, the only advantage the .338 has over the .300 is that the bullet starts at a larger diameter. Both should be more than sufficient to the task mentioned.

[6pt-sika]

I’ve had several of both and liked them both . However my application with a 300 Win Mag or the 300 Weatherby was with 150’s or 165’s , I liked 165’s the best in both 300’s . My application with the 338 usually started at 200 grains up to 225 grains all being polymer tipped bullets with the exception of the Nosler 210 Partition .

[44shooter]

Both rounds are based on the same case and are of similar length so powder capacity will be similar. Maybe the 300 will hold slightly more because of its slightly more forward shoulder, but it can't be much. The 338 obviously uses bigger bullets which can be made heavier than 300 (.308) bullets.

If weights are kept the same such as 180 or 200 grain, then the two rounds will be close. Actually the 300 may have an edge since its bullet is longer in relation to caliber, thus decelerating slower and penetrating more generally.

However, the 300 tops out at about 200 gr for pointed hunting bullets and about 220 for RN. The 338 is typically used with 225 to 250 gr pointed hunting bullets with some bullets in to 275-300 range.

I don't know if it is much more powerful, but to me, if a case can propel a bigger heavier bullet, then that round is more powerful than the lesser caliber cartridge on a similar case. I think the differences are probably more apparent on the heavy end of both bullet and game.

[daisygordoninc]

Thanks guys, that helps a lot. It seems bullet weight is probably the biggest issue if we
are looking for something over 200 grs. .

[AJMD429]

In terms of big-game hunting, I'd go with:

1. Bullet placement.
2. Bullet construction.
3. Taylor Knock-out Value.
4. Trajectory

The first is shooter and gun depwmdent, the second is load dependent, and the third is cartridge (and load) dependent.

More commonly "foot-pounds of energy" is compared, but that correlates less reliably with clean kills.

I put Trajectory in only because it affects likelihood of good shot placement 'out there' and unfortunately tends to be worse with similar-size cartridges for the one with higher TKO, whereas the higher velocity ones with night ft-lbs of energy have better trajectories.

Lots of tradeoffs, options, and decisions. That's what makes it so FUN....

[buckeyeshooter]

I’ve had several of both and liked them both . However my application with a 300 Win Mag or the 300 Weatherby was with 150’s or 165’s , I liked 165’s the best in both 300’s . My application with the 338 usually started at 200 grains up to 225 grains all being polymer tipped bullets with the exception of the Nosler 210 Partition .

I don't own a 300 WM, but I do own a 300 H +H and a pair of 338 WM. Loads with bullets under 200 grains are like 110's in a 300. Not efficient and only for light weight game (meaning deer is lightweight for the 338). I use 250 grain bullets or 300 grain bullets. There is a big difference between a 250 grain Nosler on game vs a 175 grain bullet in 338. So, my thought is we are looking at oranges and bananas here. If you use the most efficient bullet, then the .338 shines, with a sub 200 grain bullet... about the same performance. I would also say, using 300 grain Woodleighs ( softs or solids), the .338 pushes right up on the .375 H+H. Except, my .375 has less recoil than the big bullet .338.