New Short Mag powder question


September 8, 2008, 10:21 PM

I've read a number of articles on the new Super Short Ultra Compact Micro Magnum rifle rounds that, well pretty much every manufacturer from Ruger to Hi-Point seems to have introduced in the last few years.

Pretty much every author says that the performance gains they're seeing (especially magnum performance in shorter barrels) is largely due to improvements in powder technology. And then they mention (of course) that these powders aren't available to us, the reloading public.

Aside from the narrow-minded and (hopefully) short-lived desire to sell proprietary ammo, why are the manufacturers not releasing this amazing new stuff?

What is the new tech, anyway? Some formulation of blended powders? (Just one idea I came up with...that we're definitely NOT supposed to try at home.) Is there actually any more than the usual possibility of danger from us using these powders? Are these new "proprietary-wildcats" being SAAMI rated at 75- or 85,000 psi or something because the only guns built in these calibers are known-quantity new production types that can handle it?

I generally tend to believe that there's nothing truly new under the sun, but I suppose that might not be true in this case. How are they getting these numbers? And when will we?


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September 9, 2008, 04:59 PM
This is only a guess, but since the short magnum calibers are similar in design, based on the 404 Jeffery (right?), and are obviously very efficient cartridges, wouldn't they require a powder with a very specific burn rate for maximum efficiency? Or is the OEM powder just that much better than commerical? This sort of reminds me of Lazzeroni ammo and the difference between factory velocities vs. hand-loaded velocities.

September 9, 2008, 06:14 PM

I've read that some of them are based on the .404, but I have no idea if they all are.

I'm more intrigued by the "mystery" powders being used. What I mean is, I'd assume they are optimized for burn rate (and other things?) vs. case volume, projectile weight, barrel length, shoulder angle, primer energy, and perhaps a bunch more things, but I don't believe that they can get these velocity numbers simply by tweaking cartridge efficiency with the same old powders we all know and love.

I'd love to know what the trick is...and when they'll start selling the stuff!


September 12, 2008, 12:33 PM
Short magnum rifle ammo leverages work done by Lazzeroni and PPC cartridges.

The marketing, from what I have read, is magnum performance in a short action light rifle.

Ruger, specifically, has the RCM Ruger compact magnum, they are getting 300 Win mag performance out of a 20in barrel short action rifle 300 RCM. And Similar performance on 338 RCM compared to 338 Win mag. Must be a killer on recoil, a magnum with light rifle.

What they do is start with a body width of a belted magnum ~.532in and the case is straight or barely tapered.

September 12, 2008, 12:53 PM
Yep, that's pretty much what I've read, too.

Any idea on the powders they're using?


September 12, 2008, 01:30 PM
So far, that has been the complaint, is reloader powder to get up there. Alliant has Reloder 17 out, marketed at short magnum cartridges. I haven't seen any load data with it.

My brother wants the 700 stainless in .300 WSM. The 300 WSM and 300 RCM look good to me, but none of the others. Maybe if they made a .25 WSM instead of a .25 WSSM.

I am interested in case life as well.

September 12, 2008, 01:55 PM
I can't speak to the ruger RCM, it's a Hornady developed cartridge. I can speak to 300 WSM loads, mine is a Browning A-bolt. As for powders, mine likes the traditional slow burning range, H-4831 SC seems to be the best for mine. I've also used AA 4350, and a lot of RX-19.

As for how they do it? It's really no secret. They just upped the top pressure limit. Simple huh? Most rifles run at 55,000 psi. The short mags run at 65,000 psi. Increase pressure, you increase velocity. To answer the underlying question, I do achieve the velocity levels WITH accuracy, that they claim the cartridge is capable of. The few factory loads I shot at the beginning to get brass, also went to the claimed velocity levels. Yes I have a chronograph.

The WSSM'S are notorious barrel burners. The throats are only good for around 300 rounds, then it's time for a new barrel. There's no free lunch. You have to pay for that kind of performance.

September 12, 2008, 05:20 PM
I would have assumed they'd be too hard on barrels, but 300 rds? Roy Weatherby himself would be astonished at that one! Yikes!

I don't suppose I'll be getting one then. 300 rds is probably about what I'd put through it testing loads! Maybe if I hunted more than once every few years and shot less than once a week it would make sense.

Kind of disappointing!


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