Home Forums Hunting & Shooting Ask The Gunwriters Powder question for JB: pressure, % consumed, etc.

John, I'd like to know more about powders and suitability for various applications. Since there are firearms and cartridges out there that are rated from about 14k to 65k psi, it follows that smokeless powders are designed, manufactured, and marketed with a wide range of suitable applicability overall, but any single one might be very limited in range of suitability for various applications. I think we're all noticed that it is sometimes noted that "a certain powder" will operate best when pressures reach a certain threshold, and I assume that this threshold has something (if not EVERYthing) to do with getting a complete, or nearly complete burn. It seems to me, on the other hand, that operating a powder at pressures beyond its intended use would be dangerous because higher pressure tends to accelerate burn rate which in turn raises pressure more creating a regenerative pressure runaway situation (I think of it as "tipping over"). Is that a demonstrably valid concept?

It seems safe to assume that powders like Bullseye, Unique, Red Dot, and W231 will burn completely at the lower pressure ranges where shotguns and some handgun cartridges are meant to operate...just as it seems safe to assume that powders like Retumbo and H1000 would not operate well at 30,000 psi.

I've always imagined that a powder meant for use in shotshells might become quite dangerous if one were to try to operate it at 40,000 psi (for example). Is there a basis in fact for that notion? Is there actually a known pressure threshold where powders tend to detonate?

How would you determine through research or investigation of data the threshold at which a powder begins to operate the best? In other words, is there a characteristic parameter you might look at?

What insights can you share regarding this aspect of smokeless powder?

Thanks in advance.

RiverRider,

To answer all your questions would require far more time and space than I'm willing to try to put in a few paragraphs here.

Do you have any of my GUN GACK books? All contain entire chapters on smokeless powders, and probably the chapter from the first book would pretty much do the job--though both GG II and III expand on that.

I've got all the Gack books, John. I've read them but it has been a while...and maybe my memory is not quite as good as I often think it is. I'll go back and review and see what I can glean.

Thanks for the response.

If you have any questions after that, will be happy to give 'em a try.

In the meantime, I'll look at those chapters again too!