300 or 378 Wby case?

Ok guys a real world question. I have had 2 300 Weatherby rifles as well as a 257 and a 270 so it isn't a question of whether that's the brand I want or not. The hunting I'm doing now is primarily Montana/Colorado and my home state of Alaska. Lately I've found the shots are either right here or out to 600 yds which honestly is as far as I care to shoot. The question I have for anyone who has used them is, do you see a benefit to moving up to the 378 case (30-378/338-378) compared to the 300 case (300/340 Weatherby). I'm mainly interested in the farther shots and not wanting them going anywhere. You don't want to be tracking a blacktail on Kodiak, trust me. Like I said this is for anyone who has used them. Appreciate the opinions

The cartridges you mentioned are very capable with the appropriate bullets and shot placement. But KODIAK,Sweet.
Never been there but on my bucket list.
I have a 30/378 shooting 230 Berger's at a comfortable 3060fps. But its semi custom Mark 5. To help manage recoil I had a heavy varmint 9twt 27" with a
T4- Terminator muzzle brake installed.
So it's not a lite gun, loaded and ready
2oz shy of 12lbs. BUT very comfortable to shoot. Another option but not a Weatherby, you may consider a 300 or 338 Rem. Ultra. Mag.
Hope this helps.

Thanks it does. That sounds like a great rig. I actually don't shoot light rifles well so I'm always the guy walking around with the 10lb plus rifle happy as can be. I agree with Brady Miller when he says it's got one purpose and it needs to work when I use it

Perman5 said:

The question I have for anyone who has used them is, do you see a benefit to moving up to the 378 case (30-378/338-378) compared to the 300 case (300/340 Weatherby). I'm mainly interested in the farther shots and not wanting them going anywhere. You don't want to be tracking a blacktail on Kodiak, trust me.

Click to expand...

I've used and enjoyed the .300 WBY for a long time and plan to continue using it for a long time.

But I also shoot the 30-378 and the 338-378 and enjoy both as well.

For the yardage you're concentrating on, the 300 WBY shooting a heavier 215 Berger will place you right where you want to be, somewhere around 2,300 ft/lbs at 600 yards. Plenty to anchor but also kill properly. You supply the shooting ability and let the bullet bring home the meat!

I will confess that I have been doing some shifting of cartridges for the last few years to the 300 Norma Mag. and the .338 Norma Mag. Neither of these is factory available in the Mk 5 so this limits your choices.

Continue with the .300 Weatherby Mag. and enjoy the adventures! Those of us Stateside are envious!

Great advice thank you. Yeah I reload so I just wasn't seeing the advantage on paper of a new set of components moving up in case size but real life and paper are very different so I thought I'd ask before I went down the rabbit hole again. Love my 300 and wondered if it was going to be more of a good thing.

Perman5 said:

Ok guys a real world question. I have had 2 300 Weatherby rifles as well as a 257 and a 270 so it isn't a question of whether that's the brand I want or not. The hunting I'm doing now is primarily Montana/Colorado and my home state of Alaska. Lately I've found the shots are either right here or out to 600 yds which honestly is as far as I care to shoot. The question I have for anyone who has used them is, do you see a benefit to moving up to the 378 case (30-378/338-378) compared to the 300 case (300/340 Weatherby). I'm mainly interested in the farther shots and not wanting them going anywhere. You don't want to be tracking a blacktail on Kodiak, trust me. Like I said this is for anyone who has used them. Appreciate the opinions

Click to expand...

There is always an advantage to going with more case capacity for more OOMPH, especially at long ranges and with heavier bullets. However, at your 600Y range parameter, your 257, 270, and 300 WBY are plenty for the task, especially with the right bullet.

I do not have a .300 WBY, but I have a custom .30 Lara (.300 Jarrett improved) with a 28" could propel the 215/230 reasonably well. It will also shoot a .300 WBY round.

(.300 WM, .300 WBTY, and .30 Lara)

My .270 AI propels the175 Matrix at 2996 FPS out of a 30" barrel, so your .270 WBY will be faster. My .257 WBY propels the 163 Chinchaga at 2915 FPS out of a 22" barrel. Good luck and happy safe hunting.

Have in my possession 257 Bee, 6.5-300 Bee, 270 Bee, 300 Bee, 340 Bee & 375 Bee. The last 3 are on the same Win Model 70, the first 2 are on another Win Model 70 and I have another 257Bee on a Weatherby.

This is my take on this scenario. Back in 2000/01 I started developing my own wildcats based on the 416 Rigby Improved case. Had looked at the 300/340-378 case, but 2 things stood out to me that would hamper what I wanted to do, first was the belt, took up too much room in my chosen platform action, second was the radius shoulder and neck length. I wanted as much case capacity as I could get. The cost of Weatherby brass was another factor here, it is like gold prices…
I stumbled upon a huge supply of Kynoch 416 Rigby ammo that had been stored and forgotten about in the 60's or so.
So, I had plenty of brass to play with, just had to pull bullets and that gave me brass. I didn't know that cordite was very difficult to remove, however I managed.
So, this is what I started with, developed my design on 30, 33, 37 & thought about 7mm & 416.
Now, the difference in performance with a case the size of the 378 Bee, or 416 Rigby is not huge, but when you can safely exceed 3400fps with the desired bullet weight, read that as heavy target bullet, the increase is downright a game changer at distance.
Using 120g+ of powder is now getting very expensive, but if you're only hunting, it really doesn't matter. I built mine for hunting and ELR steel shooting, already burnt out 2 barrels, one 30 cal and my current 33 is about done and very tired at 900 rounds.
Just don't shoot fast…
I agree with @FEENIX .

Cheers.

300 weatherby is alot of round. 30-378 is a beast.

I have a 300 and love it, but the next one will be a 340 weatherby I think.

I definitely love my 300's and really am leaning toward a 340 as my big gun. So far it's seems like the 378 case isn't giving that next step to a level like the 300 case does from say a 300 win mag. That's what my brother has always used and it's great but there's no mistaking it to a wby. Heck my 257 hand load has more powder than the 300 win mag load I had for him

Perman5 said:

I definitely love my 300's and really am leaning toward a 340 as my big gun. So far it's seems like the 378 case isn't giving that next step to a level like the 300 case does from say a 300 win mag. That's what my brother has always used and it's great but there's no mistaking it to a wby. Heck my 257 hand load has more powder than the 300 win mag load I had for him

Click to expand...

Other than bullet size/diameter, .340 WBY (104g H20) is not much of a step up from .300 WBY (100g H20).

Depending on the source, the .300 WM has an H20 of 94g, while the .257 WBY has 84g.

If you look at it like step ups, then the next step up from a Weatherby is the RUM, step up from there is 378 case.
There are other options that are conceivable, such as the Norma Mag Improved, 338 Lapua Improved. None of these were around when I developed my wildcats, that is why I did, there just was nothing BIG to play with other than belted magnums that just didn't cut the mustard.
The RUM had only been released after I bought my first reamer…

Cheers.

I have a .300 Win, Weatherby, and RUM. The RUM is a noticeable step up from the Weatherby without sacrificing magazine capacity. And it's easy to get accurate loads.
The .340 is a sound choice- smooth to shoot and hits big animals harder than any .30 cal can.

Perman5 said:

I definitely love my 300's and really am leaning toward a 340 as my big gun. So far it's seems like the 378 case isn't giving that next step to a level like the 300 case does from say a 300 win mag. That's what my brother has always used and it's great but there's no mistaking it to a wby. Heck my 257 hand load has more powder than the 300 win mag load I had for him

Click to expand...

For 600 yards your .300 Wby. is perfect!
If you do decide to go bigger, you mentioned .340, I would suggest the .338-.378 Wby. instead. My reasoning is it is more bang for the buck, pardon my humor. Seriously though, you can do everything you want to do with it, plus take it beyond with extremely good long range high BC bullets! Once I thought 500 yards was a long shot, then I took my first long range class. It is big time fun! Enjoy.

MagnumManiac said:

If you look at it like step ups, then the next step up from a Weatherby is the RUM, step up from there is 378 case.
There are other options that are conceivable, such as the Norma Mag Improved, 338 Lapua Improved. None of these were around when I developed my wildcats, that is why I did, there just was nothing BIG to play with other than belted magnums that just didn't cut the mustard.
The RUM had only been released after I bought my first reamer…

Cheers.

Click to expand...

Agreed! Another worthy note is that the .338 LM/I and .338 Edge (a missed opportunity by Remington, but good on Shawn Carlock for realizing it) need a COAL at the 4.00" range to take advantage of those long, heavy, high BC bullets. I was initially going to build a .338 LM/I but went with .338 Thor (NM/I).


My .338 Thor with a cut-out brass with 300 Berger at 3.7" COAL touching the lands.