Many moons ago, I had one of the first H&R Trapdoor carbines to come into the country.
I had read something about 'duplex loading', using a small charge of smokeless pistol powder under a reduced charge of BP. All the info said was - "reduce your BP by 10 grs."
I don't recall exactly what I used for smokeless, but it was most liklely Unique as I shot a lot of it then; probably about 5 grs. I was shooting 'as cast' 405 gr, hand lubed with bicycle wheel bearing grease. It was extremely clean burning as I recall, bore and brass. I recall shooting over week end camping trips with no issues of corrosion without cleaning.
More recently, I found a duplex recipe in Pat Wolfe's book on loading for the Springfield Trapdoor - 7 grs SR4759/52 grs FFg under the Lee 405 HB. This equates to 62 grs BP. Having some Lee HBs on hand, I gave it a go.
Recoil was a tad stiff in the carbine, but off hand accuracy at 50 yds was surprisingly good.
Both the bore and brass looked like I had been shooting smokeless! I deprimed at the range and dropped the brass into a jug of soapy water. When I got home, the water was barely discoloured. I rinsed it, dried it and didn't even tumble it.
The bore cleaned up in seconds with my usual BP cleaning fluid.
Now I'm thinking I want to try duplexing in my 50-70s using the same formula.
I'm also toying with the idea of a duplex load for my wife's .357 mag Uberti RB rifle. It shoots well with BP, but gets crudded up PDQ with 100% BP.
I had read something about 'duplex loading', using a small charge of smokeless pistol powder under a reduced charge of BP. All the info said was - "reduce your BP by 10 grs."
I don't recall exactly what I used for smokeless, but it was most liklely Unique as I shot a lot of it then; probably about 5 grs. I was shooting 'as cast' 405 gr, hand lubed with bicycle wheel bearing grease. It was extremely clean burning as I recall, bore and brass. I recall shooting over week end camping trips with no issues of corrosion without cleaning.
More recently, I found a duplex recipe in Pat Wolfe's book on loading for the Springfield Trapdoor - 7 grs SR4759/52 grs FFg under the Lee 405 HB. This equates to 62 grs BP. Having some Lee HBs on hand, I gave it a go.
Recoil was a tad stiff in the carbine, but off hand accuracy at 50 yds was surprisingly good.
Both the bore and brass looked like I had been shooting smokeless! I deprimed at the range and dropped the brass into a jug of soapy water. When I got home, the water was barely discoloured. I rinsed it, dried it and didn't even tumble it.
The bore cleaned up in seconds with my usual BP cleaning fluid.
Now I'm thinking I want to try duplexing in my 50-70s using the same formula.
I'm also toying with the idea of a duplex load for my wife's .357 mag Uberti RB rifle. It shoots well with BP, but gets crudded up PDQ with 100% BP.
