Blending Powders

[Bringsteen]

I am NOT recommending this. I have NO experience doing this.

The original .223 load the military worked up for the M-16 included two powders. Combining powders is something that is done by those with comprehensive understandings of propellant and primer chemistry, internal ballistics, and access to all the equipment needed to measure such things.

I imagine that some of the "wonder loads" available for sale by certain retailers are products of powder combinations. I am wondering if anyone has any experience in such things.

[Oreo]

I don't personally know anything about it. But I did see a thread somewhere where a few people who did know something about it said that it is an old practice that has been pretty much eliminated due to more modern powders. I think they also said it was something that was only done with large caliber rifle rounds. The primer would set off a small primary charge of fast burning powder to more quickly light off the secondary, or main charge of slower burning rifle powder. This was aided by the fact that these powders were compressed & held in place by the bullet so that there would be no "mixing" of the charges in the case.

Now someone with some real knowlege on the subject needs to chime in & correct my mistakes. :)

[freakshow10mm]

Duplex charges are common in blackpowder and the larger big bores (40 caliber rifles and up).

Usually something like 2gr of Bullseye first, then your 70-120gr of blackpowder.

I've never heard of the military using a duplex loading in the M16. Interesting.

[ept000]

I have heard guys talking about it, but they always seem to have limited information. Kind of like I knew a guy, that knew a guy, who used to hunt with a guy, who's cousin talked to a guy, that was told by a friend, that READ IT ON THE DAMN INTERNET!

[Bringsteen]

Freakshow,

The article is in the February 2008 edition of Handloader. It is titled ".22 Gustafson: On the Road to the 5.56x45mm and the M16." The article indicates that when the cartridge was being developed, a large batch of .222 Remington was loaded with 41 grain Sisk bullets, over 16 grains of IMR-4198 and 2 grains of IMR-4227.

I was trying to be coy about the whole thing, but I am really interested in whether blending powders could create a 10mm load that exceeds what can be done with 800-X. McNett exceeds it. Buffalo Bore exceeds it. I believe both of them stay within SAAMI specs.

[Washington,D.C.]

The original 454 Casull loads were made up of blended powders. Some were two powders but the hottest loads were a mix of three powders. It's not needed with the powders available these days.

[layusn1]

Well, since no one else has said it....DON'T DO IT!!!

But if you do...will you take a video when you shoot em...might be good stuff for youtube....J/K

[MakeMineaP99]

You can be damn sure McNett is using custom powders, blended to his specs. However, he has data available to him that make this a safe practice.

[Gary Newport]

You can be damn sure McNett is using custom powders, blended to his specs. However, he has data available to him that make this a safe practice.

Well, maybe SOME of the time! :yikes:

http://glocktalk.com/forums/showthread.php?t=813538

[MakeMineaP99]

Alright, let me qualify my statement:

Generally, he knows what he is doing.

[layusn1]

Well, maybe SOME of the time! :yikes:

http://glocktalk.com/forums/showthread.php?t=813538

They make it sound like way too many Glocks KB...

[Gary Newport]

They make it sound like way too many Glocks KB...

Just those subjected to excessive pressure...like any firearm.

[freakshow10mm]

Freakshow,

The article is in the February 2008 edition of Handloader.
Thanks, I have the issue in hard copy.

You can be damn sure McNett is using custom powders, blended to his specs. However, he has data available to him that make this a safe practice.
Not all the time. My "mentor" is a guy who knew Mike from before he handloaded. It is safe to say he learned most everything from my "mentor".

Mike uses 800X in a lot of his loads. A lot of his loads are over SAAMI spec for the 10mm, usually between 40-42K psi, especially the 135gr load.

There are some custom powders he uses, mainly in the rifle, such as the 45/70 load that generates high velocity but the pressure is only trapdoor levels.

[MakeMineaP99]

Is your mentor Paul "Fitz" Jones?

[freakshow10mm]

Don't know his real name, just email relationship. He's on TFL, Ruger forum, 1911 forum.

[Bringsteen]

Mike uses 800X in a lot of his loads. A lot of his loads are over SAAMI spec for the 10mm, usually between 40-42K psi, especially the 135gr load.

It sounds as though you don't think that McNett is using either blended or noncanister powders for his 10mm. I've gotten some amazing speeds using 800-X, but it seems that Doubletap's stuff is even faster. I suppose I am just wondering how he does it.

[freakshow10mm]

Not for all of them. It's a mix of commercial and industry only powders. His high velocity/low pressure loads are definately industry powders, such as his 45/70 loads that perform to Marlin levels, but have trapdoor pressure.

[918v]

Why blend powders when we have Power Pistol?

[Bringsteen]

Why blend powders when we have Power Pistol?

If Power Pistol were the ne plus ultra of pistol propellants, then we would not need to do anything but use Power Pistol. But the fact is that there are a number of canister propellants that are better than Power Pistol for any number of applications. And a handful of custom ammo manufacturers are using noncanister powders and/or blending powders to get maximum velocities for various cartridges.

[918v]

But it's not the pressure, but how the pressure curve builds that is important. PP will not KB your gun no matter how much you cram into the case.

[Bringsteen]

But it's not the pressure, but how the pressure curve builds that is important. PP will not KB your gun no matter how much you cram into the case.

To the extent that is true, you still have to consider that a given case has only so much capacity. The potential advantage of a noncanister powder or blend is that you can get more energy AND a better pressure curve for your caliber/gun combination. If you can get pressure to peak as the bullet approaches the end of the barrel, you will get higher velocities than if the pressure peaks as the bullet leaves the case. This is in part because in the second situation, the pressure peak is wasted on overcoming the inertia of the stationary bullet. In the case of Power Pistol and any number of other slower powders, the theoretical pressure peak is somewhere beyond the end of a 5" barrel. If you shoot an automatic with a 5" barrel (as I do), this means that a fair part of Power Pistol's energy is wasted. Power Pistol is a great powder, it is just not a panacea.

Let's face it: the search for the perfect powder will never be over, for any of us.

[918v]

In actual practice, however, slow powders outdo faster powders in short barrels, despite the reported inefficiency. But I see where you are heading with this in terms of muzzle flash.

[Bringsteen]

I agree.