300 Weatherby Mag. vs. 300 Ultra Mag. vs. 300 WSM

[MontanaRifleman]

When doing load work for my WSM, I worked up for the 210 Berger using RL17 and max'd @ 2935 which is within 200 fps of what I could push the 210's in my 300 RUM using Retumbo. So based on my experience, with the right powder a WSM can push the heavier bullets quite well. Another good reason to choose the WSM is the barrel will last a lot longer than the WBY or RUM and so will the brass.

 

[Trickymissfit]

When doing load work for my WSM, I worked up for the 210 Berger using RL17 and max'd @ 2935 which is within 200 fps of what I could push the 210's in my 300 RUM using Retumbo. So based on my experience, with the right powder a WSM can push the heavier bullets quite well. Another good reason to choose the WSM is the barrel will last a lot longer than the WBY or RUM and so will the brass.

Looking at the chamber drawings of the .300 WSM and the .300WBY, one sees a great difference between the neck length so the two rounds. One has a 35 degree shoulder and the other figures out to be around 45 degrees. The vortex of the flame pathe in the WSM case is just inside the front of the lip in the neck. Better than some, but no where as good as the Weatherby neck design. The WBY mag uses about 12% more powder to gain over two hundred feet persecond in velocity (probably more). The longer neck seriously comes into play when you start using 220+ grain bullets

I doubt there's many folks that are going to know the difference in barrel life between the WSM case and the WBY case, but who knows? Personally, I'd take the .308 Norma over either one of them
gary

 

[MontanaRifleman]

The case drawing I am looking at on Ammoguide shows the WBY with a 20* shoulder. It does have a slightly longer neck by about .023, but the WSM's sharper shoulder and sharper neck/shoulder junction (vs the radius WBY junction) I would think more than make up for the length difference. The RUM neck is close to the WBY in length but has a sharper 30* shoulder.

I have never burned out a barrel in WSM, WBY or RUM so all I can go by is what I hear and read and I have heard and read WSM's get good barrel life in the 2000-3000 round range whereas the RUM maybe a 1000 or more with the WBY maybe a little more than the RUM.

If a WBY can push a 210 bullet 3130 fps, that would equal the 300 RUM performance (in a 26 barrel).

 

[EBOLAVIRS]

I would also go with the Weatherby. Had my choice when I ordered a custom rifle a few years back and debated for a long time the choice. The more experienced western hunters I talked to the more 300WBY rose to the top.

Not to change your mind but if you are planning on loading for it, I would look at something in the 7MM (stw,wsm,rum) line of rifles as the 30cal stuff has been pretty hard to come by during this latest frenzy. I have always seen 7MM stuff around when looking at bare shelves where 30 cal stuff used to be.

 

[ski0617]

I would go with the 300 RUM, I personally have one and I love it. You say no more then 700 yards, but if a big one steps out at 800 I am willing to bet you're trigger finger is going to be itching for him. Kick is a little much for some people but I have a break on mine so its actually fun to shoot. Great knockdown power! Good luck

 

[Trickymissfit]

The case drawing I am looking at on Ammoguide shows the WBY with a 20* shoulder. It does have a slightly longer neck by about .023, but the WSM's sharper shoulder and sharper neck/shoulder junction (vs the radius WBY junction) I would think more than make up for the length difference. The RUM neck is close to the WBY in length but has a sharper 30* shoulder.

I have never burned out a barrel in WSM, WBY or RUM so all I can go by is what I hear and read and I have heard and read WSM's get good barrel life in the 2000-3000 round range whereas the RUM maybe a 1000 or more with the WBY maybe a little more than the RUM.

If a WBY can push a 210 bullet 3130 fps, that would equal the 300 RUM performance (in a 26 barrel).

you have a bad set of drawings. Virtually all Weatherby cases are in the 45 degree range. If you go from the centerline of the radius, you will see a neck closer to .38".
gary

 

[Deleted member 46119]

So many options.

I'm sure any of the Sort Action Magnums, Long Action Magnums or Ultra Magnums in .30 caliber will do what you want. Factory rounds are available for all but it might be worth considering what you could get when out of town. 300WSM and 300WM will both be found at wally world once the supplies return.

I have shooting and reloading experience with a couple of the suggested calibers.

If it were me, I would keep in mind impact power (foot lbs), using a metric of no less than 1000 puts them all pretty close.

I have a 300WSM. 3 touching at 300 yards is all up to me. Factory Copper is still sub MOA.

I don't have a 300 Win Mag but all the books and programs have the WM and WSM very close. Just long action vs. short action.

I am loading for a 300RUM. Christensen Arms all carbon fiber. Definite sub 1/2 MOA with copper. Clover leafed at 300 yards on new gun rounds 14,15,16. Testing since them has been in high winds but still sub MOA at 300 yards including horizontal.

I don't have any info on loading/hunting the 300 Weatherby but if you go that route, I'd suggest buying a Weatherby. I live near Paso Robles and visited Weatherby last week. FWWIW, my 300WSM is a rebarreled Weatherby.

My next 'big' build is a 338 Edge on a Weathery action but it will be a target/tactical rifle.


Enjoy.

 

[MontanaRifleman]

you have a bad set of drawings. Virtually all Weatherby cases are in the 45 degree range. If you go from the centerline of the radius, you will see a neck closer to .38".
gary

This is the Ammoguide drawing. They say it's SAAMI verified. IME, the neck is the vertical portion.. I would think any part of the radius would be considered shoulder.

.300 Weatherby Magnum - AmmoGuide Interactive

Just talking theoretically, but seems to me that the WBY radius facilitates the combustion flow up through the neck and into the throat vs the sharp junction of standard shape shoulders and necks which focus it more in the neck region.

 

[Trickymissfit]

This is the Ammoguide drawing. They say it's SAAMI verified. IME, the neck is the vertical portion.. I would think any part of the radius would be considered shoulder.

.300 Weatherby Magnum - AmmoGuide Interactive

Just talking theoretically, but seems to me that the WBY radius facilitates the combustion flow up through the neck and into the throat vs the sharp junction of standard shape shoulders and necks which focus it more in the neck region.

I just looked at the case drawings in the Hogdon, Speer, AA, and Hornaday manuals. AA is the only one that calls out the angle in any of the Weatherby prints, and they don't do it with the .300. But the .300 is close enough to the 7mm to be considered similar. That angle is 47 degrees. The venturified neck & shoulder is hard to develop a true neck length on, but at worst case it's close to .330" and could be construed to be .09" longer. Engineering wise the neck ends where the neck meets the small strait line of the shoulder (it's not much) as the .187" radius is actually part of the neck. I would prefer half that number at the max, and really closer to 1/3rd that number. The venturified shoulder has two distinct advantages. First is gas flow, and the second is rigidity. A true radius is always stronger than a square corner formed from strait lines. How much here is debatable, but it will compute to be stronger.
gary

 

[Bart B]

As far as accuracy goes for all these cartridges, I'd pick a rimless version. Belted cases have a accuracy track record that's not all that great, at least in competition where thousands of rounds have been fired by the best marksmen.

New belted cases are great; been used to win many a match and set records since the 1935. The US military teams, as well as top ranked civilians, tried reloading their fired .300 H&H, .30-.338 and .300 Win Mag cases with conventional dies to cut costs, but the reloads never shot as accurate as new cases. Military teams quit reloading and used only new cases. Civilians modified a standard full length sizing die.

Reloaded, belted cases have a problem with that ridge about .005" to .008" in front of the belt caused by the new case expanding against the chamber with its head hard against the bolt face. Unless sized back down to body diameters, that little ridge interferes with the back end of the case fitting the chamber exactly the same for each shot. Special body dies were made to size the fired belted case totally down to the belt; normal full length sizing dies don't. The body die was made by cutting off the bottom of a sizing die just above the belt clearance and just below the body-shoulder junction. Innovative Technologies - Reloading Equipment now sells a collet die to do the same thing.

While the accuracy difference between new and properly full length sized belted cases were equal, fired cases with that ridge still there typically shot about 1/4 to 1/2 MOA less accurate. That's enough for comptitors shooting the best scores to notice.

One other thing is barrel life and shootability. The more powder burned for a given bore diameter, the less life the barrel has. More powder also causes more recoil while the bullet's going down the barrel; more muzzle axis movement before the bullet exits.

 

[Triple BB]

If the Ultra mag was a great round we'd see it in use at the 1000 yard meets. Instead it's the WSM, Ackley and the WBY mags
gary

Maybe true, but he's only wanting a 700 yard gun. Fact is, any of them will work fine out to 700 yards. As stated the RUM has the most versatility. If yer working off a budget, start doing some research on costs including the rifles themselves as well as cost to reload. Might help shape yer decision.

 

[4xforfun]

Maybe true, but he's only wanting a 700 yard gun. Fact is, any of them will work fine out to 700 yards. As stated the RUM has the most versatility. If yer working off a budget, start doing some research on costs including the rifles themselves as well as cost to reload. Might help shape yer decision.

The reason the 300 ultra isn't poppular with the 1K crowd is the brass quality..it sucks. BUT...we now have Shawns Bertram EDGE brass....I am thinking that this could be necked to 308 and you would have some GREAT Ultra brass.

Oh, my vote......SA...300 WSM. Long action....300 WBY.

 

[Triple BB]

I have 5 boxes of Nosler 300 RUM brass that I'm pretty impressed with. But hey, that's just me...

 

[Bart B]

I just looked at the case drawings in the Hogdon, Speer, AA, and Hornaday manuals. AA is the only one that calls out the angle in any of the Weatherby prints, and they don't do it with the .300. But the .300 is close enough to the 7mm to be considered similar. That angle is 47 degrees.

Here's SAAMI's specs for the .300 Wby Mag cartridge and chamber. How does its shoulder numbers compare with the other drawings?

http://www.saami.org/PubResources/CC_Drawings/Rifle/300 Weatherby Magnum.pdf

Most interesting to me is the bullet diameter's spec'd at .3083".