.300 Weatherby or .300 RUM

M

mnoirot64

New member
Greetings, friends. I am actively shopping for a high powered .308 caliber magnum. I am planning to use it for long range (600+ yards) target shooting and the occasional North American big game hunt (elk, moose and bear). I had considered the .300 WINMAG, but I really like the flatter trajectory the Weatherby and RUM should offer with between 100 and 200 extra FPS. I plan on reloading all of my ammo, so the ammo cost is not a big consideration. Nor is recoil as I have no issue with hard hitting heavy calibers. All said, what is your preferred chambering in a 30 caliber magnum. Thank you in advance for your input and suggestions.

Michael Noirot
Clarksville, Tennessee
 
I have had both. Rum is about 75 fps faster in the weight bullets I care about. I have no favorite between the two. I reamed the 300 wby up to a 416 Rigby with no case taper and a pushed forward 40 degree shoulder. For all practical purposes, its a 30-378 Wby now. My favorite .30 Cal is the Win. Mag.
Between the two cartridges you asked about, to me, it would all boil down to whether you like a 700 or a Mark V better.
I have two Mark V .300 Wby rifles that have never been shot. I bought them for their actions. $435 at Walmart several years ago. (long story but I bought 8 of them)
 
I own and reload for, amoung others 300WBY and 340WBY. The RUM cases are based on a necked down 404 Jeffrey case. A rebated rim design with pluses and minuses.

My source of apprehension with the RUM cases, are that they are made by REM.

A couple of years ago was browsing around in Big Bears and spotted some Rem brand bag brass for 300WBY, $7.00, for 20 pieces. The cheapest I have ever found Weatherby brand, made by Norma, was $23.00 for 20 pieces. I bought them and was disappointed.

I knocked a grain off of my pet handload, 86.5gr RL25, Hornady 190gr JSPBT. Chrono's @ 3100fps with no sign of excessive pressure, and very accurate. The same load minus a grain showed signs of high pressure on the first shot and had a blown primer on the second. There was little trouble with extraction, and I didn't fire anymore of those. Those two rounds were about 40fps slower than the avg for my regular loads, so go figure.

Only point here investigate the quality of components using all available sources, and always look for signs of high pressure. And all cases are not made equal.
 
I've had both slight difference in case capacity and one advantage is RUM headspace on the shoulders and doesn't have the Wby freebore.

I haven't seen any 300RUM brass at our local Sportman's Warehouse but they do have unprimed 300 Wby.

Not sure about magazine length on the Wby but with SAAMI Max loaded at 3.600" for the 300RUM and 3.560" for the 300Wby and Rem magazine length at 3.700" you may be limited on some bullets.

I never used either for target shooting as they just made few range trips between hunting season checking existing loads is all. I don't have either rifle now decided to stay with 30-338mag for bull elk.


Depending on what bullets you may not really gain much over 300Wby/300RUM.
 
I'd get one chambered for one of the big rimless bottleneck 30 caliber cartridges from either Remingon or Winchester. They're a lot easier to reload for best accuracy than anything with a belt on its back end. Smaller ones will be easier to shoot accurate due to a bit milder recoil and have longer barrel life. But the bigger ones shoot the same bullet out a little faster but barrel life will be shorter.
 
I actually prefer belted magnums in hunting rifles. The belt is more accurate across extremes in temperatures and enviornmental conditions.
 
I actually prefer belted magnums in hunting rifles. The belt is more accurate across extremes in temperatures and enviornmental conditions.
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How does that happen?

Never heard of that before.
 
the two are pretty much on equal ground. both have about the same amount of models available, the same aftermarket/accurizing mods available, about the same price for ammo and reloading components and in the end there is very little difference in velocity.

flip a coin.
 
The Navy loads 300 Win Mag with a 220 SMK and a charge of H1000 spec'd to 68k psi (5k over SAAMI) for the Mk248 Mod0 sniper load. It is a legit 1500 meter load.

Don't know why you would need a WBY or RUM unless you just want something different. Generally I recommend going with beltless over belted, simply to make reloading easier, but with quality 300 Win Mag brass cheaper than any of the alternatives listed, I'd make an exception there.

Jimro
 
Jimro:
300 Win Mag with a 220 SMK and a charge of H1000 spec'd to68k psi (5k over SAAMI) for the Mk248 Mod0 sniper load.
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In case someone think's that's a dangerous load. . . .

SAAMI's .300 Win Mag service maximum probable sample mean pressure's 68.1Kpsi, so that load's at the upper limit of industry standard specs. Maximum probable lot mean pressure's 65.6 Kpsi.

The cartridge' proof load pressures are 85.5 Kpsi and 91.5 Kpsi, respectively. Few, if any of the fired cases are ever reloaded, so the danger issue's minimized.
 
Belted magnum cartridge is not as easy to reload???? Perhaps it is me, but I don't find that to be true at all. Would you guys please explain why you believe that statement to be true.
 
sc928porsche said:
Belted magnum cartridge is not as easy to reload???? Perhaps it is me, but I don't find that to be true at all. Would you guys please explain why you believe that statement to be true.
Click to expand...

Probably what they are referring to is that the belt tends to interfere with resizing and makes it hard if not impossible to fully re-size the cases. The cases often start getting stretched and the brass gets thin ahead of the belt after only a few reloading cycles. You cannot reload these cases as many times as a standard cartridge and there are a few special tricks to determine whether the case is getting too thin and time to toss.
Example:
headspace-2.jpg


Personally, I went with .300WM myself cause I didn't think the barrel life trade off was worth the trajectory gains since I am rarely shoot out past 500-600 yards and I bought it more for long range targets than hunting (higher volume shooting). Disclaimer, the following info is based on my barrel life model (which in my own defense was based on about 3 weeks of research into the topic), but should at least trend in the general ballpark. By my calculations for the same bullet and powder with max loads:
The .300 Weatherby gains 4% velocity over a .300WM for about a 16% hit in barrel life.
The .300RUM gains about 5% velocity over a .300WM for a 27% hit in barrel life.
 
Here's my take on this...

Barrel life is irrelevant to me... If I burn out a barrel it means I'm actually getting to shoot a reasonable amount...

Between the two cartridges.. I like the fact the 300 RUM is a beltless cartridge.. The deal killer with these two cartridges is the fact the only brass source with the 300 RUM is Remington, which is sub-par at best.. With the Weatherby cartridges you have access to Norma brass, which is some of best quality brass in existence, probably only surpassed by Lapua.. Between these two cartridges I'll take the Weatherby.. Mine does everything I want it to do..
 
While belted cases became the rage for accuracy afficianados back in 1935, it wasn't until the late 1950's that top level competitive shooters using them learned of their issues. When Sierra Bullets changed their 30 caliber match bullets from FMJBT design to HPBT ones, their better accuracy permitted reloaders to see subtle differences in case design and suitability for reloading into very accurate ammo.

When a new belted case is fired, it's belt is hard against the chamber headspace ridge. As pressure rises, the case head gets pushed back against the bolt face. That moves the case belt back off the chamber ridge exposing a few to several thousandths of case body in front of the belt that's not supported by the chamber wall. That short part of the body expands leaving a tiny ridge where the unsupported part ends.

Traditional full length sizing dies did not resize all the case body back down; the case body diameter at that ridge and back to the belt remained the same. When the firing pin smacked the primer driving the case forward in the chamber, that ridge often hung up on the chamber's headspace point and interfered with repeatable case movement into the chamber when fired. I was usually enough to notice that such reloads didn't shoot as accurate as new cases; the new cases didn't have that ridge. So, something had to be made that got rid of that ridge.

The top and bottom of another standard full length sizing dies were cut off the bottom just above the belt clearance part, the bottom squared and its inside edge slightly radiused. When set in the press so its bottom went all the way down the fired case stopping against the belt, that ridge and the case body behind it was sized down; typically to near new case diameters.

Some used this "body" die before full length sizing in a standard die, others afterwords. Either way, belted cases so sized shot with best accuracy. While the improvement wasn't much, it made a 1/4 to 1/3 MOA improvement at long ranges.

In talking with military team members who shot 30 caliber magnums in long range matches, many of them tried resizing their fired cases the traditional way and never got the accuracy new cases attained. So they quit the reloading stuff with .30-.338's and .300 Win Mags giving all their once fired empty cases to civilians to use.
 
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