Du-plex loads?

[.22-5-40]

Hello, everyone.  I was wondering if any of you use du-plex loads (small smokeless priming charge) in your BPCR rifles for cleaner burn?  If so, what type powders do you use, and how much?  Thanks.

[John Boy]

If so, what type powders do you use, and how much?

Thuer, your question is like a paint brush - too broad.  The rule of thumb is 5% smokeless powder of the normal black powder powder charge of a specific caliber, with the BP charged reduced by the 5%.  There are several nitro based powders that alone will equal BPCR pressures with the proper number of grains.  I know you have asked this question on several forums so you should be familiar with the powders.

In addition, I know I have pointed you to the Goex website for the listing of all charges by caliber for the grade and grains by bullet weight for the black powder reloads.  Use these BPC charge amounts as the starting point and reduce the charge by 5% for the smokeless powder

Also, had you done a search on the Internet for 'black powder duplex loads' you would have found a long listing of listing of sources with the answers to your questions. 
Here's a starter for you ...
http://www.google.com/search?q=black+powder+duplex+loads&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a

And from a historical point, duplex loads were used for over a 100 years ago with the introduction of bulky powders such as King's Semi Smokeless

I hope I have answered your broad brush question and pointed you to several sources to obtain the specifics to it

[.22-5-40]

Broad Brush question?  If you re-read the original post..all I was asking is if anyone of Graybeards members use a du-plex load in their black powder guns?  And if so, what smokeless powders they are using.