Why Don't Ammo Manufacturers...

[mortensen]

List the type of powder and powder charge on their box's? Why, because more different calibers are being made available to the general hunting and shooting public. And this is a good thing. My rant is that some of these wildcat calibers have been considered barrel burners in the past, but with the advent of slower burn powders they can expect to have a normal life expectancy. But there is no mention of the powder or charge on the boxed ammo. However, some do list the bullet weight. Can anyone chime in and give a reasonable explanation regarding the powder and charge reference. The only thing I can think of is that the ammo is produced in lots. If you purchase ammo with a lot number of 12345 and go back a month later and purchase another box of ammo and it has a lot number of 67890, could this indicate that there may be a slight powder change or powder blend?

Those of you who may be new to firearms, ammo or reloading should aquaint yourself with SAAMI. Everything to do with firearms, bullet, powder and a whole lot more are based on SAAMI specifications.

http://saami.org

Ammo manufacturers along with reloaders have specific guidelines developed by SAAMI which we follow and are found in your reload manual. We have a minimum and maximum powder charge which must abide for your chosen bullet weight.

One of the most important, overlooked and critical considerations besides a powder-bullet recipe is pressure. If your new to this topic, here's a couple of examples you should be aware of.

Let's take a simple example.

Cartridge: 40 S&W

Load Type: Pistol

Bullet Weight: 135 GR. Nos JHP

Maximum Charge: 7.5

Vel (ft/s): 1324

Pressure: 32,500 PSI

(I'm not going to list all the different bullet weights in between these two illustrations).

Bullet Weight: 200 GR. Hdy XTP

Maximum Charge: 4.7

Vel (ft/s): 903

Pressure: 33,600 PSI

What you see is that when the bullet weight increases, the powder charge decreases. When the bullet weight increases the velocity decreases and the pressure increases. This is all about keeping the chamber pressure at a safe level. The powder charge will always be typically lighter for a heavier bullet.

Simply stated, a heavier bullet can cause more harm at a lower velocity. The difference is in the momentum or inertia, or kinetic energy, however you want to phrase it, heavier can carry more energy.

If you are near the maximum safe pressure with a 165 grain bullet and use the same amount of powder to push a 180 grain bullet, the higher chamber pressure could very well be over the maximum safe pressure and cause catastrophic failure.

Edited January 17, 2011 by mortensen

[Strut10]

It's called "proprietary information".

It's why KFC doesn't list the recipe for their chicken on the side of the bucket.

Another reason is probably that it wouldn't matter if you knew anyways. A lot of factory loads are burning powders that we, as reloaders, can't get even if we did know what they were.

[mortensen]

It's called "proprietary information".

It's why KFC doesn't list the recipe for their chicken on the side of the bucket.

Another reason is probably that it wouldn't matter if you knew anyways. A lot of factory loads are burning powders that we, as reloaders, can't get even if we did know what they were.

Thank you. Good points and explanation and a good reason to reload.

Edited January 18, 2011 by mortensen

[Tecumseh]

Most ammo manufactures use a custem blend powder that has to be reliable for a broad range of rifles and pistols and like Strut10 said they guard that like a launch code for a nuclear missle silo.

[m gardner]

Some "powder" is actually loaded into the case in a semi-liquid form. I think Hornady's "Light Magnums" were like that. Other powder like the British Cordite is put in the case then the neck is formed and the bullet loaded.There's lots of reasons you couldn't duplicate what they do.