What Happened To The 300 Remington Ultra Mag?

[ISS]

I had one built about a year after the RUM cartridges came out. A year later, I could not find brass, just loaded ammunition about five bucks a pop. So, I sold it; and got my investment back. It's still fun finding brass from Remington. They have a habit of not supporting big cases.

I now have a 98 Mauser switch barrel set, 300 and 375 H&H. I bought an OM 70 300 H&H from a friend. It came with dies and over 500 cases. I bought 200 rounds of 300gr 375 ammunition, and I am still working my way thru that. I am still hoping to get back to RSA this fall before the rainy season starts in September.

 

[ISS]

Nothing in the world, including Africa; will ever know the difference being shot with the old 30 Hollands Super and the RUM. It's the bullet and the shooter that count...

ISS

 

[jackieschmidt]

I’m going to start a thread in the Long Range Forum asking about a long range build using the 338 RUM in my Bat M action.

I actually have an invite to a place to shoot out to one mile. It’s a ranch owned by my Kidney Doctor. He is kinda into ELR shooting.

 

[Alex Wheeler]

Jackie, if you have a magnum bolt Id do a 338 edge. If you have to buy a bolt Id do a 338 lapua improved. Its the 6br of 338s.

 

[jackieschmidt]

Thanks Alex.
Yes, I have to buy a mag bolt. I would like to keep the current bolt at .473.
I see your point on going to the EDGE as the better choice.

 

[Alex Wheeler]

They make a .580 bolt for the M.

 

[jackieschmidt]

Alex, just for my info, does anyone shoot the 300 RUM or the 30/338 Weatherby in ELR using the heaviest Berger or Sierra bullet offerings.? If so, how to they stack up in real world performance to the big 338’s.

 

[SKWERLZ]

Alex, just for my info, does anyone shoot the 300 RUM or the 30/338 Weatherby in ELR using the heaviest Berger or Sierra bullet offerings.? If so, how to they stack up in real world performance to the big 338’s.

I shoot with a guy that runs with a 300 rum.
He runs mostly 230 Berger’s but is testing the new 245 LRHT
At a mile it’s a chip shot
Not far behind my 338 running solids.
I’m at about 13.8 mils to a mile and he’s very low 15’s mils to the mile and he’s loaded somewhat conservatively as he’s on a 700 action.

 

[Alex Wheeler]

Alex, just for my info, does anyone shoot the 300 RUM or the 30/338 Weatherby in ELR using the heaviest Berger or Sierra bullet offerings.? If so, how to they stack up in real world performance to the big 338’s.

Yes guys do run big 30s in some elr classes. The NF challenge is one the the big 30s do very well in. I do a lot of big 30s and 338s. I played with them a lot. We used to have a 2000yd match for group and score we shot on 1kyd F class targets. Id really like to see that get going again, and it might one day. Ballisticly they are similar. However, in my opinion the big 338s do everything better. The reason I say this is they are much easier on throats, they tune easier and stay in tune better. I have shot smaller with them than the big 30s as well. The 30s shine when we need a lighter hunting rifle. The 338s just recoil too much to shoot well in a light rifle. But if you can have the weight, Ill take a 338 every time.

 

[ISS]

Two sayings come to mind.
1. do not waste time and money trying to reinvent the wheel.
2. if it ain't broke, you can't fix it. So, just enjoy it until you break it; then pay somebody who knows what they are doing to do that.

 

[jackieschmidt]

Two sayings come to mind.
1. do not waste time and money trying to reinvent the wheel.
2. if it ain't broke, you can't fix it. So, just enjoy it until you break it; then pay somebody who knows what they are doing to do that.

Sounds about the way we feel about the 30BR in Short Range Score.

 

[FNSafari]

There is a good article in the March/April Rfleshooter magazine by Craig Boddington titled "What Really Matters" page 64-63. It touches on case capacity and caliber a bit and has some connection to this thread except its hunting related.

 

[Swamplord]

In non-wildcat 30 cal cartridges, the 300 RUM is probably the best moose hunting cartridge ever developed, IMO

Runs with the 30-378 Wby but burns less powder for same velocity & easier to tune up accurate long range loads
Can download with appropriate powders to match velocities of all the lesser cap. cartridges and you'll have eternal brass life

bullets from 100 gr to 250 gr
Peterson & ADG making brass

The only better moose hunting cartridge is the 338 EDGE but .... the 300 RUM doesn't need a muzzle brake

 

[jackieschmidt]

I started this thread wondering about the 300 RUM, and if any of you are following my thread in Long Range PRS ELR Forum, you can see I am now 3/4 of the way into a ELR build in 338 Ackley Improved.

At the very least, I’m getting to make use of some of the pieces I had laying around gathering dust.

Do you think I would have been smarter just selling them off?

 

[CJ6]

Absolutely not. Finish it up and enjoy.

 

[ebb]

The only problem I see is finding RL33. Others work, my shooting mentor said he got 150FPS more speed with less pressure than Retumbo.

 

[Ranger188]

I started this thread wondering about the 300 RUM, and if any of you are following my thread in Long Range PRS ELR Forum, you can see I am now 3/4 of the way into a ELR build in 338 Ackley Improved.

At the very least, I’m getting to make use of some of the pieces I had laying around gathering dust.

Do you think I would have been smarter just selling them off?

Absolutely not.
Even if it doesn't turn out the way you thought it should, you'll always
learn something valuable.

 

[FNSafari]

There is an interesting article in the April 2025 "Shooting Times" magazine by Allan Jones on the 280 Ackley Improved. Jones is a retired ballistician. It involves looking at the improvments Ackley strove for in the designs. he wrote that "the greatest benefits from his designs were with heavier bullets and the slowest, case filling propellants of the day." Anyway, very interesting article from one who should know.

 

[Charlie-NY]

There is an interesting article in the April 2025 "Shooting Times" magazine by Allan Jones on the 280 Ackley Improved. Jones is a retired ballistician. It involves looking at the improvments Ackley strove for in the designs. "he wrote that the greatest benefits from his designs were with heavier bullets and the slowest, case filling propellants of the day." Anyway, very interesting article from one who should know.,

And can be read on line now - which I just did.