Smokeless behind BP?

[Myshootinstinks]

New here. I’m using Goex 2f in the 40-65. I read somewhere that if you load with a small amount of smokeless, it “cleans” the bore so you don’t need to run a patch between shots.
Has anyone done this and if so what smokeless and how much? Currently loadin 60-65 gr 2f w/ 400 gr Snover. All in a Browning hi-wall.

[HWooldridge]

Try searching on duplex loads - quite a lot of info contained on the site about the practice.

[fc60]

Greetings,

I shoot a Browning Hi-wall in 40-65.

I use R-P brass, 5 grains of Reloder 7, 50 grains of Swiss 1 1/2, an 0.030" wad with the 400 grain Snover cast of 20:1.

It certainly shoots cleaner than straight Black Powder.

Cheers,

Dave

[ascast]

IMR 4759 was a great powder for Duplex loading. No longer made, but you may find some old stock. Star with about 5 grains smokeless and increase until the bore is all clean. Rl7 is also good, I think 2400 also works but check it. Do try a search.

[2TM101]

New here. I’m using Goex 2f in the 40-65. I read somewhere that if you load with a small amount of smokeless, it “cleans” the bore so you don’t need to run a patch between shots. Has anyone done this and if so what smokeless and how much? Currently loadin 60-65 gr 2f w/ 400 gr Snover. All in a Browning hi-wall.

https://www.youtube.com/watch?v=ONup8G2vpgE
https://www.youtube.com/watch?v=_bpx0WKlSpQ

I've been duplexing with Crimson powder instead of Black. 8% smokeless and 92 % Crimson by weight.

I can use bullets with petroleum based lube on them as there is no Sulfur. Likewise powder coated and not worry about fouling building up.
The residue left on the gun cleans up with a damp cloth. Bore looks the same as if I was firing regular rounds.

[greyhawk]

New here. I’m using Goex 2f in the 40-65. I read somewhere that if you load with a small amount of smokeless, it “cleans” the bore so you don’t need to run a patch between shots.
Has anyone done this and if so what smokeless and how much? Currently loadin 60-65 gr 2f w/ 400 gr Snover. All in a Browning hi-wall.

4227 is great, it is near identical density to Black so load 5 to 7 grains of that and reduce BP by same

[Sandro_ventania]

ideal duplex, you put the BP first and the smokeless on top. If you are concerned about dirt, then use crimson powder instead of BP...clean barrel, you can use petroleum products, normal wax, etc.

[indian joe]

ideal duplex, you put the BP first and the smokeless on top. If you are concerned about dirt, then use crimson powder instead of BP...clean barrel, you can use petroleum products, normal wax, etc.

Smokeless in first has been the norm for a century - that has got me clean barrel and Extreme Spread in single digits - plus about 100FPS velocity increase - plus a quick and easy loading procedure

Other way up MIGHT offer a marginal increase in velocity - that needs an unbiased test

Aint broke dont fix it always my mantra..............................

[muskeg13]

Smokeless in first has been the norm for a century - that has got me clean barrel and Extreme Spread in single digits - plus about 100FPS velocity increase - plus a quick and easy loading procedure

Other way up MIGHT offer a marginal increase in velocity - that needs an unbiased test

Aint broke dont fix it always my mantra..............................

In a .50-70: Lyman 515141 445gr
(Old Red Can) Goex FFg 65.0gr 9 shots avg 1168.2 fps SD: 10.7
" " 60.0gr over 5.2gr SR-4759 4 shots avg 1253.8 fps SD: 12.9
.50-70 Lyman 515141 435gr
(Old) Goex FFg 60.0gr/ 5.0gr SR-4759 avg: 1230 fps SD: 20.5
Hodgdon Triple 7 FFg 60.0 gr (by volume) avg: 1295.6 fps SD: 17.3

About 3" 100yd groups for all loads. Straight BP loads produced enough fouling after 5 shots that the chamber throat (and bore) were swabbed with a wet patch followed by a dry patch or the cartridges wouldn't fully chamber. The duplex and Triple 7 loads shot cleanly enough that no swabbing between shot strings was needed.

[greyhawk]

In a .50-70: Lyman 515141 445gr
(Old Red Can) Goex FFg 65.0gr 9 shots avg 1168.2 fps SD: 10.7
" " 60.0gr over 5.2gr SR-4759 4 shots avg 1253.8 fps SD: 12.9
.50-70 Lyman 515141 435gr
(Old) Goex FFg 60.0gr/ 5.0gr SR-4759 avg: 1230 fps SD: 20.5
Hodgdon Triple 7 FFg 60.0 gr (by volume) avg: 1295.6 fps SD: 17.3

About 3" 100yd groups for all loads. Straight BP loads produced enough fouling after 5 shots that the chamber throat (and bore) were swabbed with a wet patch followed by a dry patch or the cartridges wouldn't fully chamber. The duplex and Triple 7 loads shot cleanly enough that no swabbing between shot strings was needed.

You got + 85 FPS with 5 grains
I use 7 grains 4227 guessed + 100FPS -----close enough eh?

Tried sr 4759 didnt like it as well as the 4227 --two reasons 1) the stuff was at least 40 years old - seemed ok but coulda been suspect 2) its more bulky, loose a couple grains space.

Blackpowder is homebrew I can get ten without a clean - or twenty with some blow tube (cleaner than Goex - I like that red can vintage goex)

[Myshootinstinks]

Very helpful and thanks! I suppose any smokeless of about those burn rates would be worth a try. 4227 and 4759 as well as 4198 are hard to find. Manuel lists full smokeless loads in h335, Benchmark, BLc etc and I have those powders.
Where does a guy get “crimson” and how does it perform?

[Sandro_ventania]

Very helpful and thanks! I suppose any smokeless of about those burn rates would be worth a try. 4227 and 4759 as well as 4198 are hard to find. Manuel lists full smokeless loads in h335, Benchmark, BLc etc and I have those powders.
Where does a guy get “crimson” and how does it perform?

See you here!
https://castboolits.gunloads.com/sho...-Golden-powder!

[muskeg13]

I have one 1# can of 4759 and decided to begin using it for duplex loads since it's long been discontinued I don't want to go to the effort of working up full 4759 loads only to quickly run out. Plus, most of the published duplex loads seem to have used 4759 as the priming charge, and at only 5 grains per shot, it will last a while. I have a few cases charged with 5 gr of RL-7, but I haven't tried these yet. I only have small quantities of 4227 and 4198, but these powders are still (occasionally) available. Looking at the 4759 grains, I was immediately reminded of 5744. It's in the same general burn rate band, and I have a large quantity of it, so I'm probably going to try duplexing with it next.

Has anyone ever heard of or tried duplexing Pyrodex?

[greyhawk]

I have one 1# can of 4759 and decided to begin using it for duplex loads since it's long been discontinued I don't want to go to the effort of working up full 4759 loads only to quickly run out. Plus, most of the published duplex loads seem to have used 4759 as the priming charge, and at only 5 grains per shot, it will last a while. I have a few cases charged with 5 gr of RL-7, but I haven't tried these yet. I only have small quantities of 4227 and 4198, but these powders are still (occasionally) available. Looking at the 4759 grains, I was immediately reminded of 5744. It's in the same general burn rate band, and I have a large quantity of it, so I'm probably going to try duplexing with it next.

Has anyone ever heard of or tried duplexing Pyrodex?

I think the burn rate for duplexing is proly important ----the bulkiness of sr 4759 and 5744 ? not so much (lose a couple grains more of black from the combo load)

[muskeg13]

I think the burn rate for duplexing is proly important ----the bulkiness of sr 4759 and 5744 ? not so much (lose a couple grains more of black from the combo load)

I believe you are right. Anything in the general burn rate range will probably work, but 4759 and 5744 are quite coarse and take up BP room. I'll have to admit to having multiple goals in attempting duplexing (seems to have an aura of alchemy to it):
1. Does it work without safety issues (blowing up the old rifle wouldn't be a good thing)?
2. Does it work to reduce fouling?
3. Does it work to be at least as accurate as straight BP?
OK. I think my initial attempts have confirmed the first 3 goals.
Careful duplexing works very well.

Next: I'd like a bit more ooopf, without the fear of overstressing and blowing up an antique. We're faced with the reality that our modern drawn cases don't hold the same charges of BP powder that they did 100-150 years ago, and there's speculation that our modern BP may not be as good as the old stuff. Modern cases are much stronger, thicker and have less capacity.

Long answer to your post. A duplex charge, in the same burn range, but with a finer/less dense smokeless charge, would allow room in the case for a few more grains of BP, so you may be able to increase the BP charge and achieve a bit more velocity and maintain safety.

We're never going to be satisfied we have the "perfect" load. That's why this is our hobby.

[indian joe]

I believe you are right. Anything in the general burn rate range will probably work, but 4759 and 5744 are quite coarse and take up BP room. I'll have to admit to having multiple goals in attempting duplexing (seems to have an aura of alchemy to it):
1. Does it work without safety issues (blowing up the old rifle wouldn't be a good thing)?
2. Does it work to reduce fouling?
3. Does it work to be at least as accurate as straight BP?
OK. I think my initial attempts have confirmed the first 3 goals.
Careful duplexing works very well.

Next: I'd like a bit more ooopf, without the fear of overstressing and blowing up an antique. We're faced with the reality that our modern drawn cases don't hold the same charges of BP powder that they did 100-150 years ago, and there's speculation that our modern BP may not be as good as the old stuff. Modern cases are much stronger, thicker and have less capacity.

Long answer to your post. A duplex charge, in the same burn range, but with a finer/less dense smokeless charge, would allow room in the case for a few more grains of BP, so you may be able to increase the BP charge and achieve a bit more velocity and maintain safety.

We're never going to be satisfied we have the "perfect" load. That's why this is our hobby.

you know I have always been a tad sceptical about 'free lunches' -
figured if we got an increase of 100FPS then it seemed safe to assume we also got an increase in pressure ?

somewhere on this forum somebody posted figures to the contrary for duplex loads - that surprised me and I kinda took it with a grain of salt - dont know where to direct you for that info

[HWooldridge]

Makes one wonder about the original duplex experiments and the intentions of the first people who tried it. Black powder was still king of the hill when smokeless made its debut, and well established as a propellant, so why would anyone want to mix the two? I suspect the marked decrease in fouling was a pleasant discovery, and may have been the primary reason for continuing the practice. We know there isn't a huge increase in velocity so why go to the trouble unless it was to extend shooting sessions and possibly increase the accuracy potential.

I've tried the 10% rule with several types of smokeless in a 45-70 Sharps. This ranged from Red Dot to 2400, and I couldn't tell much difference in performance, but I also didn't own a chronograph at that time and have no idea of velocities. I seem to recall the faster powders felt like they kicked a bit more - but that might have been my imagination. There was no practical difference in accuracy or fouling if all else was equal, so the brand of smokeless didn't appear to have much effect. YMMV and I wouldn't argue with anyone who claims one type or another works best for them.

[Griff]

Has anyone ever heard of or tried duplexing Pyrodex?

Yes... combined with dirt it makes a good fertilizer. I won't let it near my firearms.