Reloading for suppressors

[MuzzleFlash]

I had a "well, Duh!" epiphany today when doing some reloads and wanted to get other's take.

Obviously, there are MANY factors that go into producing the quietest possible subsonic reload for a given pistol caliber suppressor. However, one thing seems obvious - for a given powder charge, the gas produced will have the same mass as the powder. Thermodynamics would seem to indicate that a smaller mass of gas would start out cooler and cool down quicker.

So everything equal, would a rule of thumb be to look for the lightest charge weight that will produce the target velocity, burn cleanly and reliably cycle the gun? Or do some suppressors reach peak efficiency at gas volumes above the minimums?

Thoughts?

[amphibian]

I think you are on the right track there.
I am using the same load Dr. Dater of Gemtech is using which is fast and clean burning VV powder. Since it is a fast burning powder it is also a small powder charge.

I did try some loads I made long time ago with AA#7 which is much slower burning and it was a lot louder in the same suppressor.

I have a Gemtech MK9K and it is very quiet. I compared it side by side a Gemtech Talon upper. The Talon uses the same baffle stack as the Mossad and Raptor. My Mk9k was mounted to my Gemtech 5" barrel on my M16. So it was a fair comparison. Using the same ammo everyone there said mine was quieter as it has a deeper tone.
I asked Dr. Dater about this and he told me that since the MK9k is a larger volume suppressor, it will be quieter across varying loads while the newer cans need a higher pressure round which work the gasses harder so that it will trap the gasses. There was also an article in SAR about the Mossad suppressor and it also mentioned about how its performance got better with higher pressure rounds.

I don't know if this helps you at all...

[Brian Ski]

I don't know anything about the gas produced vs the charge size, but I have ran across something a long time ago when I started reloading. I don't think it has much influence on the 9mm ammo. But was told if you have a rifle caliber, and you are working on light charges, there have been some really high pressures built up. The way I understood it was the powder would lay horizontal in the casing and fill it up basically halfway or so. Instead of igniting the back of the powder and buring forward, the primer would flame across the whole topside and increase the pressure by igniting all the powder at once.

I was told if you wanted extremely light loads in a rifle round was to fill the case with a charge and use a filler. I don't remember how it was spelled. Something like "kapok" was told to be used. It burned clean. It is the stuff in a life vest.

I am going from memory. It has been a while.

[Brian Ski]

Originally posted by MuzzleFlash
I had a "well, Duh!" epiphany today when doing some reloads and wanted to get other's take.

However, one thing seems obvious - for a given powder charge, the gas produced will have the same mass as the powder.
Thoughts?


You are dealing with someone here with a public school education so be easy. What do you mean by same mass for powder charge vs gas produced? Are you saying weight or volume??

I know that if you take about 1 grain of primer powder you can make a fireball the size of a golfball.

Then again if you take the same amount of smokeless powder you will get a much smaller "fireball".

Don't ask me how I know.:D

[dustindu4]

mass means weight

Cookie has mass in his ass

[MuzzleFlash]

Originally posted by dustindu4
mass means weight

Cookie has mass in his ass LOL! Cookie has super admin privs so don't tempt him to customize your avitar :D

Yes mass is proportional to weight. IIRC, they are 1 to 1 at sea level.

So if you take a 1 kg mass at sea level it weighs 1 kg. If you put it in the space shuttle, it has almost no weight, but still is a 1 kg mass.

Another way of saying it is mass has weight when acted upon by gravity.

I did go to college, but many moons ago and the laws of use-it-or-lose-it definitely apply in my case :)

[carcass]

Very Good Point on low mass = low heat capacity of resulting gas.

I don't have a suppressor, but for my pistol loads, I use Hodgdon Clays. It's a really fast burning powder. I use 4.4 grains in my .45 ACP with a 200 gr SWC and it still makes IDPA major. Out of a 5" barrel, it's about 850 fps. With my previous powder, Win. 231, I had to use like 5.3 grains for the same effect.