8mm RUM

[RUMLUVER]

I have been giving great consideration to building a 8mm RUM using the .338 RUM case. I think it would be a great idea considering I could use 185 and 200gr TSX bullets from Barnes at 3200+fps. I would like to see Swift come out with a 8mm Scirocco it would be a great addition the bullet line up for 8mm's considering you could use it in the .325WSM also. I wouls like to use the 220gr slugs also. What do guys think of such a wildcat?

[Rocky Raab]

How different would it be from a standard Rem 8mm Magnum?

I'm don't know what the two case capacity numbers would be (in either grains of water or percentage difference).

But, in general, you can use this rule of thumb: For the same caliber, with the same bullets, the muzzle velocity will change by one fourth the percentage change of case capacity.

As an example, if the 8 RUM case holds eight percent more than the 8 Mag, you will see a two percent increase of velocity.

If the 8 Mag velocity is 3000 fps, the wildcat 8 RUM would churn up a whopping 3060 fps with the same bullet.

Edited to add: I just checked. The 8 RemMag holds 98 grains of water. My list didn't have any RUM rounds, but the 338-416 Rigby is very similar. It holds 106 grains of water. The difference is 8 grains, or a nine percent increase.

Expected velocity increase of an 8mm-416 Rigby over a stock 8mm RemMag would be one fourth of nine percent, or about 2.3 percent.

[HPBTMTCH]

Rockys right, unless you just want something different, and have the extra time and cash laying around for such a project. The 300 RUM case would be a better parent, but i doubt the gains would be worth it. An improved 338-378 necked down to 8 mm would be different, and expensive, but would have some ballistic gains.