28 nosler vs 7mm Rem Ultra Mag

Bigdanhess1989 · Nov 2, 2015

I have a question on how the two title calibers compare. Factory ammo is advertised as being higher in velocity for the 28 Nosler. While the 7mm RUM isn't loaded at the factory to be as fast it does have the higher powder capacity. In an article published in American Hunter magazine Max loads from both cartridges handloaded through identical rifles with the same length barrels(26 inches) are shown that the 7mm RUM is faster but only by 25 fps. By this information the claim that the 28 Nosler is the flatest 7mm chambering on the planet seems like false advertising. Was this advertisement ment to refer to factory loads? Or overall?

I do understand that the 28 Nosler is more efficient compared to the 7mm RUM but the claim that it's the flatest shooting 7mm/.284 chambering seems debateable.

In a second question does the 28 Nosler require "freebore"?

SJB358 · Nov 13, 2015

I think both of them have freebore built into them. I know the 300 RUM does. JD can answer up regarding the 338 RUM. As with anything else, alot depends on the bullet/case arrangement. A larger case doesn't always mean more speed if it require deeper seating in the magazine ultimately reducing powder space.

Both of them are fast, and with that size case on either, it takes alot more powder to get small gains.

Richracer1 · Nov 13, 2015

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.

Greg Nolan · Dec 16, 2015

The 7mm RUM I have shoots a 168gr NAB at 3440 fps. Accurately I believe that's notably faster than the 28 Nosler. As far as the commercial it says fastest 7mm on your dealer's shelf. They don't catalog the 7 RUM in the Remington catalog any more.

FOTIS · Dec 16, 2015

Best I ever got from the 7mm rum was 3305 fps with the 160 AccuBond and retumbo and I had a few of them

JD338 · Dec 16, 2015

I think the 28 Nosler is a little more efficient by burning less powder.
I to have loaded the 7mm RUM with the 160 gr AB and Retumbo and got 3300+ fps.

JD338

SJB358 · Dec 16, 2015

Fotis and Jim, I trust you both as you two have shot a lot of RUMs. How could a smaller case make more speed? Additional freebore to allow for higher peak PSIs?

I've always thought, bigger engine more safe speed? Maybe the RUM doesn't pull ahead much till it gets into the 175's and heavier?

Thebear_78 · Dec 16, 2015

Richracer1":3v4ii41j said:
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.

Get a Wyatt extended mag box. It requires very little modification to the action and will get you to 3.82"

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