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View Full Version : Duplex Loads in BP Cartridge Revolvers?



SharpsShooter
10-14-2008, 07:33 PM
My daily commute to work is a 2.5 hour affair round trip. I rarely listen to the radio so I have lots of time to think of shooting, hunting, casting etc. Now I am sure I am not the originator of the idea, but have any of you guys given thought to duplex loads in say the 45 colt?

I know several here load BP for the 45 but have never heard mention of duplexing. I plan to go to BP only for my 45 when the last of the blasphemous smokeless powder loads are gone.

I guess my questions are

1. Do or would the same rules apply regarding 10% smokeless powder and reduce the BP by 10%.

2. Would the same smokeless powders (4350, 4895, SR4759 etc.) work or are there better choices for the smaller capacity cases?

3. Would it be worth the effort to make it shoot cleaner and not tie up the revolvers with fouling so soon?

Thoughts???


SS

Dale53
10-15-2008, 12:03 AM
I have not tried duplex in a revolver. However, I have shot hundreds if not thousands of duplex loads in the 40/65 (Sharps and Browning 1885).

The best average with my .45 Colt Ruger Bisley Vaquero before "tie up" was done with "Pistol Pyrodex". My Ruger would consistently allow 75 shots before the cylinder would bind with fouling. Since I got lots of shots before binding, I had little reason to use anything else (like duplexing). Each revolver and powder will be a law unto itself.

I used Rig grease to lube and seal the cylinder pin. I have heard that STP works well, also. If you want to use Holy Black, Swiss burns cleaner than Goex (and is a good bit more powerful). I got the cleanest burn out of 3F but also the heaviest load. In a 7.5" barreled revolver for the .45 Colt you can get close to 1000 fps with a 250 gr cast bullet - with the attendant recoil. 2F burns with a bit more fouling but recoils noticeably less and the velocity will be less. Goex is quite a bit "softer" (less velocity) in both granulations and Elephant is the slowest (and least recoil) of all. Pyrodex Pistol is about as fast as Swiss.

I will be trying the .45 Cowboy Special cases and believe that I'll get a lot more shots before the cylinder binds. Since the Special only holds about 15 grs of black, the velocity will be a LOT less (as will recoil). It should be interesting...

Keep in mind that you will have to use a proper black powder lube (SPG is the gold standard but I use Emmert's home mix with excellent results). The bullet design must have a good deep lube groove for best results with black. I use the Lyman Cowboy 452664 bullet with excellent results. The Keith design should work as well.

FWIW
Dale53

John Boy
10-15-2008, 12:47 AM
Sharpshooter: Yes to 1 and 2, plus Unique. As for 3 ... Naw. You still have BP foul because duplex loads are not as clean as straight smokeless


I will be trying the .45 Cowboy Special cases and believe that I'll get a lot more shots before the cylinder binds. Since the Special only holds about 15 grs of black, the velocity will be a LOT less (as will recoil). It should be interesting...


Dale, you might be interested ... good article in the current Cowboy Chronicle:
Using the 45 Specials, they will hold 21 grs of Lido FFg. And with the 'Big Lube' EPP/UG, 150gr bullet ... they will do between 776 to 837 fps out of a NMA. I've chrono'ed regular 45 Colt's (250gr'ers) with 32gr of Goex FFg at only 680fps from Uberti 5 1/2" barrels.
PS: The Lido stuff is firecracker powder!

McLintock
10-15-2008, 12:58 PM
One of the biggest problems with cylinder binding when using BP is insufficient barrel/cylinder gap. You need at least .008", and most stock guns are around .002-4or5"; just not enough. I've seen rec's for as much as .012" for black powder guns. As .008" is a good gap for cast bullets and smokeless, I like that figure for my guns. Then, as Dale53 says, use a good lube and bullet combo and you won't have any problems no matter how much you shoot.
McLintock

August
10-15-2008, 06:28 PM
I have had complete success by coating the base pin and cylinder insert with Mobil One grease. In fact, I've had good luck with this grease in every application I've tried it in. Good boolits, properly sized and lubed seem to the the huckleberry for smooth operation. I shoot six, or more, stages with no binding using BP lube in Big Lube boolits and Mobil One on the base pin and insert. Since the forcing cone is opened up and boolits are properly sized, I get zero lead splash on the cylinder face. One wipe and it's clean after a match.