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.300 RUM or .30-.378

In the 30 cal range, I have 308/26-Nosler (a bit bigger than 30 Nosler) and 300 RUM. The RUM is a 30" Bench Rest on a R700 accurized action. I have not made 4" 1000 yard groups. ;)

I would choose the 300 RUM. "Practicality" over absolute speed. The why is below.

"There is no replacement for displacement" is true to an extent. Ballistics, like motorsports reaches a point of diminishing returns.

Case capacity and fps with 28", 245 Sierra: using QL and "knowledge" of shooting chamberings close to....
Approximately:
30-378 133 = 2950 fps
300 RUM 112.5 = 2850 fps
30 Nosler 99 = 2750 fps

Each step down is worth about 100fps with the same bullet at about the same PSI and "optimal" powder and charge. Not most accurate. Not the best COAL. Just "same" to "same". Can you "go faster", sure.

so, to me...

The 300 RUM is practical in most magnum class long actions, has the speed to reach 1000 "easy" and 1 mile practically.

If you already have the single feed action, please share which one and the bolt face and maximum COAL it handle.

Hard do advise without data. ;)
Very few people have shot 10 shot 4" groups with any rifle, let alone while shooting cartridges like the 30x378.
Which is why those records hold up as long as they do.
Even those who set the records, rarely duplicate their own record.
Back in the day, the 30x378 was used by a very small group of long range hunters.
And most of those were found in PA, mainly due to the man largely responsible for creating the cartridge.
That being the late Howard Wolfe of Mifflinburg PA.
Reasons being that there were few suitable actions for them, and few suitable powders for loading.
Howard created his own action, which was/is a large 3 lug design.
He had a large machine shop in Williamsport do the bulk of the work on them, as his small shop lacked the required machinery.
That was before C N C machines were being used, which is why there are so many good action choices at reasonable prices today.
Also companies like Berger werent in the business of building hunting bullets at that time.
The best powder was and still is H 570, which is a WW2 machine gun powder.
Howard would hesitate building a gun if you didnt have that powder.
You did what he told you as for loading, or you didnt get a gun built.
Using his action, with a 36" barrel, we loaded 112 to 114 gr of H 570 with a 200 gr SMK.
Velocity would of coarse vary a bit from gun to gun.
My velocity with my gun with 113 gr of H 570 and the 200 gr bullet was 3500 FPS with a 36" barrel.
When Sierra came out with the 240 gr bullet, i bought a box of them.
I settled on 108 gr of H 570 for a load for them.
At 1500 yards the trajectory difference wasent even close, with the 200 gr being much flatter shooting.
In fact i needed to get out to almost a mile before the 240 became the better choice.
And i frankly only know one man who i would believe, who has killed a buck at a mile in PA.
And he used a 338x378 with a 250 gr SMK to do it.
Same deal with that cartridge as well.
Believe what you see with your own eyes on the side of a mountain.
And not what some number stamped on the box tells you.
 
Once at the local gun shop there were two 30-378 barrels for sale and I've often thought about shortening one back to use shorter less costly 338 Lapua brass to save money.
 
Once at the local gun shop there were two 30-378 barrels for sale and I've often thought about shortening one back to use shorter less costly 338 Lapua brass to save money.
Well there isnt much that hasent already been done by somebody.
And that includes shortening up 30x378 chambers.
Depending upon how much you shorten it will of coarse determine what you end up with.
But say about forty years ago, Howard Wolfe decided to do that so that he could use 30 inch barrels which were plentifull,
as opposed to the 36 inch barrels which were not at that time.
Also it might be a round better suited for the 1000 yd matches at Williamsport where he was very active at the time.
Problem was the brass, which would have to be made by shortening 378 cases.
So he invested in the necessary dies in order to do that.
The cartridge worked out very well, and he found himself building guns chambered for it for other Williamsport shooters.
It was referred to by those who knew about it as the Short 30x378, or the Short Wolfe.
One guy who i knew, was from York PA, and he had Howard build him one on a Mark five Weatherby action using a straight 1"250 30" Hart barrel.
He kept meticulous records of his rounds fired, and he ended up with 134 total rounds thru the barrel when he suddenly died.
It was a very ugly gun, mainly due to the heavy benchrest stock it had along with the heavy no taper barrel.
Anyway i ultimately ended up owning it, along with the little book, dies, and what brass he had.
I took it to Howard and told him i wanted him to taper the barrel and add flutes to it, after leaving it full thickness for about 8" for an aluminum barrel block.
I bought a black and grey rough shaped laminated stock patterned after the Mc Millan, and Howards son Bob finished it up.
The gun turned out to be very attractive, and weighs right around 18 pounds.
I use 190 gr SMKs over 87 gr of Retumbo for an MV of 3350.
Hit a deer high on a leg and it will be your deer, minus the leg of coarse.
Anyway about 10 years ago a guy came to our camp for bear season.
He had recently had a gunsmith by name of Dave Bruno who i dont know, turn his 700 Rem 30/06 into a 300 Norma.
He showed me one of his cases, and i immediately said that it looked like my little Wolfe case without a belt.
So we measured them, then we weighed them both with and without water in them.
They were the same, and weighed within one grain when filled with water.
So in reality, what Howard did was to create a 300 Norma about 30 years before there was a 300 Norma.
In todays world for a hunting gun, thats the direction i would go as opposed to having a 30x378.
Mind you, the 30x378 is a great cartridge, but its not as great as the larger 338s when you get out past about 1500 yards.
 
If you look closely at a 300 Rum case you will find that the head of the case is rebated so as to fit a standard size magnum bolt.
My first 30x378 was built on a Hart #4 custom single shot action with a standard size magnum bolt face.
We used 338x378 Wby brass necked down to 30 cal, as the 30x378 brass wasent available at that time.
And we turned down the case heads so they fit a standard magnum bolt face.
The head of a case is solid brass, the heads of the larger diameter cases is simply more solid brass.
But that was back then, and this it now, when better options are available to us.
And a better option for any large capacity case like the 30x378 is one of the many custom actions available today.
I am a very old fan of Savage rifles, i currently own five of them.
But i wouldnt even consider building a 30x378 or a 300 Rum either on one of their actions.
The 112 Magnum Target is chambered in the .338 Lapua Magnum. Why would you not consider using it for a .300 RUM or .30-.378?
 
In the 30 cal range, I have 308/26-Nosler (a bit bigger than 30 Nosler) and 300 RUM. The RUM is a 30" Bench Rest on a R700 accurized action. I have not made 4" 1000 yard groups. ;)

I would choose the 300 RUM. "Practicality" over absolute speed. The why is below.

"There is no replacement for displacement" is true to an extent. Ballistics, like motorsports reaches a point of diminishing returns.

Case capacity and fps with 28", 245 Sierra: using QL and "knowledge" of shooting chamberings close to....
Approximately:
30-378 133 = 2950 fps
300 RUM 112.5 = 2850 fps
30 Nosler 99 = 2750 fps

Each step down is worth about 100fps with the same bullet at about the same PSI and "optimal" powder and charge. Not most accurate. Not the best COAL. Just "same" to "same". Can you "go faster", sure.

so, to me...

The 300 RUM is practical in most magnum class long actions, has the speed to reach 1000 "easy" and 1 mile practically.

If you already have the single feed action, please share which one and the bolt face and maximum COAL it handle.

Hard do advise without data. ;)
It's a Savage 112 Magnum Target action.
 
Personally, I would build another 300 RUM, for the two I have, 26" and 28", are extremely accurate and deliver very good speed, I have lots of brass, and even if I didn't, there are good quality brass around. To me, there isn't enough gain to go 30-378.
 
It's a Savage 112 Magnum Target action.
Sorry, I would not put a 30-378 in a 112 but don't let that stop you if it's really what you want. Look at the "barrel block" stuff below. It applies to a 30-378.

so

300 RUM.

That said, On to the more fun stuff.

I have a 300 RUM single shot "Bench Rest" and... I love it. I don't use it for bench rest, I use it for ringing steel. Life starts at 1000. ;) It hasn't been out of the safe for quite a while due to me changing states to live in but it will be out soon! It is built on a R700 action. Barrel block mounted BR stock. Heavy setup will help with lots of things.

At the time it was built 245s and 250s did not exist so...

Accuracy loads are Berger VLD 230s at a totally low stress 2950 and 210s at 3050. Those are the accuracy "nodes" at lower pressures. I don't remember my twist rate but pretty sure it's 1:10. I'll measure it when I get going with her again. If it's 1:9, gonna try the heaviers. Remember when 210s and 230s where the heavies. :)

Here is my suggestion.

28 to 30 1:9 barrel, could even go 32 ;) I can measure the taper if you want.
Use a "barrel block" mounting system. Get the "droop" pressure off the action. This would allow more stability with a 30".
Use a BR type stock. You will just frustrate yourself trying to get a 112 and long barrel to hold if "conventionally" mounted.

It would be nice if there was a "Barrel Block" chassis system. Oppertunity?
 
WOW if it's a Lapua action, I would build a
30/338 Lapua or the AI. version.
Savage is as good a action as others. 🎅
Depending on Brass availability I don't think you can go wrong with a 30-338 Lapua Improved. Some folks might not like that extra boom and stick with the RUM though. The shortened straight up 30-378 Lapua is basically just the 300 RUM, so then it comes down to bolt face.
 
The 112 Magnum Target is chambered in the .338 Lapua Magnum. Why would you not consider using it for a .300 RUM or .30-.378?
There have been issues with Savage actions when used with the larger cartridges.
If you visit the savage shooter website you will find a stickey where there is lots of discussion about it.
 
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