Help wanted: Internal Ballistics of 5.56x45NATO Blank

[gregor_83]

Hello everyone!

I found this forum while searching for some info on a school project. The best piece of literature I have on the subject is a ballistics handbook, but it's not very helpful, so maybe there is someone here that can help.

I am doing a simulation of wall temperatures and velocity gradients of gases inside a blank 5.56x45NATO. The cartridge itself is plastic,PE) and has a zinc firing cap.

The bit I am interested in is:

- What is the velocity of the gases as they are burning off of the propellant matrix?
- What is the temperature of the gases?
- The burn time of the charge?

Here is some info on the gunpowder used, unfortunately I haven't been able to find anything specific about it either:

Primer: "CCI Large Rifle"
Powder: "NC312"

If you have any idea where I could find this information this, or can at least point me in the right direction, I would be very thankful!



Best Regards,
Gregor Grilc

 

[Cheechako]

Gregor

WOW! What kind of school do you go to? Obviously not one of our inner city public institutions.

Maybe you've already done this - but I would simply Google "Internal Ballistics". You should find enough hits to keep you busy for a while. Most importantly will be the links to other sites.

NC 312 doesn't ring a bell with me. Most US military blanks are loaded with WC Blank powder, an Olin,Winchester) product which has been around for years. Speaking of which, Googling places like Olin-Mathieson might yield some info.

Good Luck

PS - It just occured to me that some of your info doesn't make sense. For example a 5.56x45 with a Large Rifle primer?? What sort of blank is this?? One that simply makes noise or one that is intended to propel something? Two different things altogether.

Ray

 

[Spotcheck_Billy]

I have some limited information on the 5.56 blank cartridge with the designation M200, classification STD-AMCTC 5942.

It appears to be a brass cartridge with a rose-petal crimped case mouth sealed with lacquer. COAL is 1.9",48.3mm). Total cartridge weight is 107 gr. It uses 7 gr. of HPC 13 for propellant. The primer is listed as "percussion" as are the primer descriptions for all of the other military 5.56 ammo that I have on hand and I have no other designation for it.

This is not a plastic cartridge as you described in your post, so this information might not be helpful. There is a plastic 5.56 training cartridge, but it is not a blank. I can supply some information on it if you need it.