Home Forums Hunting & Shooting Ask The Gunwriters 300 RUM/AI load data

Friend of mine is wanting to build a 300 RUM/ AI and is having trouble finding load data. Does anyone have any experence with this round??? He's thinking about 200gr to 240gr bullets.

This is a joke, right? Like the letters college students used to make up to send to Dear Abbie?

Last year a fellow guest hunter at a deer camp showed me his allegedly AI'd 300 RUM. He told me of the marvelous velocities he was getting, something like 4000 fps with 180s. I asked to see a piece of fireformed brass and he didn't have any on him. When I asked about load data he said he didn't load any yet. So I had to ask where the velocity numbers came from. According to him when the charge first ignites it generates enough pressure to form the brass to the vastly improved AI configuration. Then the remainder of the charge burns so much more efficiently that it gives the major velocity boost.

mathman

Amazing--but he is not alone in this sort of theorizing. One custom riflemaker with a proprietary line of cartridges claimed much the same thing a few years ago. Or at least he did until one gun writer pressure-tested his ammo in a lab. Every load but one was way over 65,000 psi.

Apparently since then the RUM's and WSM's have pretty much killed off this guy's business, because I haven't heard much about his magic cartridges lately.

I think some of the guys at the Pennsylvania Long Range Benchrest club used to use the 300RUM with some sort of "improvement" but I don't know the name of it.

***EDIT*** It's called the Tomahawk.

$bob$

The only 'improvment' I could think of for my 300RUM would be some kind of recoil reduction without resorting to a brake!
:Grin:

Well, there is the 300 Tomahawk (AKA the 300 Rum Improved 35deg), amd a 300 RUM Improved 40deg *that I know of*, there may well be others out there. The Tomahawk adds about 4gr Water to the RUM case capacity

The big problem is "improving" the case in any meaningful way. The body is almost without taper already, and the shoulder angle is 30 degrees, so you're not going to gain any significant amount of case capacity by blowing out the shoulder to 40 degrees.

I suspect if anybody actually did this they would indeed find a way to get 200 fps more out of it. That is the nature of wildcatting, but it doesn't mean the 200 fps came from "improving" the case. Instead it came from another 10,000 psi!

At any rate, the way to obtain loading data for any such beast is to use data for the original .300 RUM as a starting load. Then keep adding powder until the chronograph indicates another 35 fps in muzzle velocity--because that's about what will be gained at safe pressures.

Google 300 Tomahawk and you'll find that the long range benchrest crowd uses them quite a bit.

$bob$

Of course they would.

Yep... But the practicality for the long range hunter is nill.

If someone truly needed more long range killing ability than a box stock 300RUM provided I'd think that a 338 Lapua would be a better choice.

$bob$

Long Range Hunter

That's our Oxymoron for the day

AGW

LOL...

AGW... Good one...

$bob$

Zing!

Apparently I am soon going to be invited to hunt mule deer next year with an outfitter who also runs a "long range" school. Am tempted to bring my .300 Savage with peep sight.

If you need to improve a 300 RUM get a 30-378 simple, I don't understand some people...

Seems like a lot of work for a small return

The reward for the work is in the telling of stories about the magic cartridge, the equally magic rifle and the totally "magiked" hunt results. Especially if the listener seems to believe what is being told. <---humor

jim

If the gain in water capacity is ineed 4 grains or so, then the potential muzzle velocity, at the same pressure, is 1%.

While I haven't seen the new 30TC cartridge in person, does it remind anyone of the .300 Savage with a .050" longer neck? Now this is real salesmanship!

Yea, and I would wear your "Floyd R. Turbo" jacket (red & black Plaid) too.

gdv