The L.C. Smith Collectors Association

The L.C. Smith Collectors Association
[ The L.C. Smith Collectors Association ]

Powder Burn Rate in Relation to Barrel Pressure?

Posted by Douglas Precourt on July 15, 2024, 6:38 pm

In my ignorant state with regards to shotgun reloading, would recipes that use slower burning powders have the lowest pressures as well. As an example, I hear about using Alliant Red Dot, Green Dot and Blue Dot regularly and I see on the attached Relative Burn Rate chart, that Red Dot is 8, Green is 19 and Blue Dot is 46. Wouldn’t I want to use Blue Dot most to ensure the lower barrel pressure?

I would appreciate any helpful instructions you choose to impart. Thanks
- Doug

Re: Powder Burn Rate in Relation to Barrel Pressure?

Posted by Douglas Precourt on July 15, 2024, 6:39 pm, in reply to "Powder Burn Rate in Relation to Barrel Pressure?"

Here is the Burn rate chart

Re: Powder Burn Rate in Relation to Barrel Pressure?

Posted by Drew Hause on July 15, 2024, 7:47 pm, in reply to "Powder Burn Rate in Relation to Barrel Pressure?"

Scroll down to the bottom here Doug. There are several vintage and modern pressure curves, including one from Hunter Arms.
https://docs.google.com/document/d/1F2sQuPm05IE4VWYYnCkvuXmYEzQoWd_SQgaAfUOZEFU/edit

The difference is most apparent comparing Dense Smokeless Ballistite with the older Bulk Smokeless powders - rapid burning dense powder had an abrupt rise and fall in pressure. The pressure curves however meet at 3-4 inches from the breech where the wall thickness is substantial.

Not a lot of practical difference in today's powders though you are correct that slower burning powders (which don't work well with light loads) have lower peak pressures, and would be the choice for heavy waterfowl loads. That was the point of DuPont Oval Progressive Buring powder for the Super-X loads.

Re: Powder Burn Rate in Relation to Barrel Pressure?

Posted by Douglas Precourt on July 17, 2024, 11:32 am, in reply to "Re: Powder Burn Rate in Relation to Barrel Pressure?"

Thank you for your explanation. This is making more of a dent in my understanding with time (line upon line, precept on precept, here a little, there a little). I recently picked up, (from Ballistic Products) a 2024 Hodgdon reloading document full of recipes using more readily available Hodgdon family powders (Hodgdon, Winchester, IMR, Accurate Ramshot), that include not only FPS, but PSI for each recipe. Separately, I learned from RST that their low pressure shells made for old guns like ours, never have a PSI higher than 7600. Using that as a ceiling I’ve been able to identify a number of recipes for 12 & 20 bore, and to a lesser extent 16 and 410 to start with.

I’m sharing this with all of you to ensure that my logic and process approach is sound.
Thanks for your help.
- Doug

https www google image

« Back to index

286

[ The L.C. Smith Collectors Association ]