7mm RUM vs 280 Nosler...

[IdahoSharpshooter]

I am thinking a new 7mm rifle. I have been looking at the RUM vs the Nosler. They are both based on the 404 Jefferys. The Nosler in 2.590" long, the RUM is 2.850". I am at a total loss to understand how cutting .260" off of the RUM (to create the shorter Nosler OAL) can result in a 200+fps velocity increase.

There are two ways to materially increase velocity: increase the powder charge (more case capacity) or seriously (in this case) increase pressure. The RUM runs at 65,000Psi, what does the Nosler operate at?

 

[fantastic]

Since I own and load for all 4 RUMs, I can say that the magazine is the limiting factor for OAL on all four. In fact, with my 7 RUM, I can't seat the bullets out far enough to touch the lands even if the magazine space would allow it. The longest OAL I can get is 3.67" and still function properly from the magazine.

 

[Doug30racer]

The rum has a half inch of free bore like a weatherby to disipate pressure. Being they are both over bored, it would be your decision to what you want. Rum brass in my area is harder to find and with the popularity on the 28, 30, 33 increasing that might be the way to go. Both will put a smile on your face.

 

[rhovee]

28 Nosler. Better brass. I would personally run the 180’s.

 

[46and2]

Since I own and load for all 4 RUMs, I can say that the magazine is the limiting factor for OAL on all four. In fact, with my 7 RUM, I can't seat the bullets out far enough to touch the lands even if the magazine space would allow it. The longest OAL I can get is 3.67" and still function properly from the magazine.

Build one on a 700 action and get a Wyatt's mag box. Mine runs at 3.840" for the mbe-3 but you can get a 4.0" version.

 

[46and2]

I am thinking a new 7mm rifle. I have been looking at the RUM vs the Nosler. The RUM runs at 65,000Psi, what does the Nosler operate at?

28 nosler operates at 65k also.
I run 28N with 175 Elite Hunters at 3215fps with RL33 and Br2 primers. Mid level pressures. Easy on brass.

 

[IdahoSharpshooter]

now I am confused. If they operate at the same pressure, and the RUM is more than a quarter-inch longer; which equals significantly more powder capacity, how is the Nosler capable of higher velocities?

 

[46and2]

now I am confused. If they operate at the same pressure, and the RUM is more than a quarter-inch longer; which equals significantly more powder capacity, how is the Nosler capable of higher velocities?

I don't know who said that.

!!There's no replacement for displacement!!
I'm pretty sure 7rum will outrun 28N.

 

[IdahoSharpshooter]

Nosler claims the MV advantage on their ammo boxes. The Lyman manual supports that, although they do not compare the same bullets across the board.
I see one advantage to the Nosler; it fits in a standard magnum magazine.

 

[46and2]

Nosler will do a lot to promote their cartridges!

 

[B23]

I bought some 338-378 ammo from Nosler back quite a few years ago, without looking, I don't exactly remember what Nosler claimed the velocity was supposed to be, but when I chrohgraphed it, it wasn't even close to what they claimed and was well over 200fps slower than what was claimed on the box.

 

[Doug30racer]

from all the adds for the nosler 28, they have the data on the 7 rum dumber down to make them look better. And most of the recent data for the rum is also on the weak side. In older reloading books for the 7 rum is its hauling a$$ compared current data. I used to shoot 154gr hornady interbonds at 3750 and latest was not to push over 3400. If i am looking for max preformance from a cartridge, I let the empty case tell me where i am at and not the books. Just be safe about it