The Accurate Reloading Forums
Duplexing BPE big bores
19 August 2006, 11:20
Bill/OregonDuplexing BPE big bores
Anyone here using a "smidge o' smokeless" to light off the black powder in their big-bore BPE cases? Please share particulars.
There is hope, even when your brain tells you there isn’t.
– John Green, author
20 August 2006, 08:01
Omnivorous_BobBill, I'm interested in this too. Today I tired every combination from 115-120-125gn Fg and FFg plus 5-10 gn of Blue Dot and also straight 135 gn FFg in both brass and plastic cases in my 10 bore with uniformly poor results.
Shots are still crossing ~4-6" at 30 yds! This is in a 5 dram gun with 700gn balls. On the plus side each barrel makes tight groups, just much tighter with straight smokeless than the "correct" BP. I would much prefer a BP or duplex load that shot to the sights.
ALL advice welcome. Thamks in advance!
Bob
DRSS
"If we're not supposed to eat animals, why are they made out of meat?"
"PS. To add a bit of Pappasonian philosophy: this single barrel stuff is just a passing fad. Bolt actions and single shots will fade away as did disco, the hula hoop, and bell-bottomed pants. Doubles will rule the world!"
20 August 2006, 09:12
Hog Killerquote:
Originally posted by Omnivorous_Bob:
Bill, I'm interested in this too. Today I tired every combination from 115-120-125gn Fg and FFg plus 5-10 gn of Blue Dot and also straight 135 gn FFg in both brass and plastic cases in my 10 bore with uniformly poor results.
Shots are still crossing ~4-6" at 30 yds! This is in a 5 dram gun with 700gn balls. On the plus side each barrel makes tight groups, just much tighter with straight smokeless than the "correct" BP. I would much prefer a BP or duplex load that shot to the sights.
ALL advice welcome. Thamks in advance!
Bob
What BP brand are you using? Have you tried loading FFFg? I use FFFg Goex, in all of my BP shot shell loadings, works much better than FFg.(higher vel.) Might also try Swiss if you can get it. It is a higher quality powder than Goex.
Hog Killer
IGNORE YOUR RIGHTS AND THEY'LL GO AWAY!!!
------------------------------------
We Band of Bubbas & STC Hunting Club, The Whomper Club
20 August 2006, 21:05
Bill/OregonBob:
Good lord man, let's see a photo of your 10 bore! Who built it when? If it was regulated with Curtis and Harvey Diamond Grade No.6, you definitely should try some Swiss 1.5 if you haven't already. Have you chronographed the straight BP vs. duplex loads to make sure the duplex isn't actually the same velocity or slower?? Do you have Graeme Wright's book "Shooting the British Double Rifle"?
There is hope, even when your brain tells you there isn’t.
– John Green, author
21 August 2006, 10:26
Omnivorous_BobHogkiller, I haven't tried FFFg yet, but will give it a shot. Goex is unfortunately all I can get here.
Bill, I didn't chrono the loads yesterday, but suspect they were in the same ~1200 fps ballpark as 135gn of cartridge gave. All of the loads I've chronoed were from rmc brass cases. 130gn of cartridge gave 1170, 40 gn BD=1170, 45gn BD=1330 and 50gn=1450fps. The 50 grain Blue Dot loads were closest to regulating but I think that's a bit too heavy for a steady diet in a 5 dram gun.
Several months back I tried some heavier charges of black but had very erratic velocities due to poorly fitting wads (not much will fit in the 2 5/8" case with a heavy charge) and slightly undersized round balls. I've got that straightened out now (I think/hope!) so will have to revisit that and try it with crimped plactic cases too.
The rifle is a J&W Tolley underlever 2 5/8" papercase 10 w/non-rebounding hammers. The fixed sight is marked 120 and the leaves 180 and 220. Barrels have been reblacked at some point and Marvin Huey just relined the case. What I think is so interesting about this gun is that the barrels are slightly choked! I have chamber and muzzle casts but I don't recall the measurements off hand, but when I tap a .775 ball in from the muzzle it falls free after 5-6", whereas they have to be driven all the way through from the chamber.
If anyone has any info or advice, I'm all ears. I would
LOVE to take this moose hunting one year!

Bob
DRSS
"If we're not supposed to eat animals, why are they made out of meat?"
"PS. To add a bit of Pappasonian philosophy: this single barrel stuff is just a passing fad. Bolt actions and single shots will fade away as did disco, the hula hoop, and bell-bottomed pants. Doubles will rule the world!"
21 August 2006, 10:52
Bill/OregonBob: That is a bloody beautiful double you have there. I think it might be worth your while to order some Swiss from Maine Powder House. There must be someone in your neck o' the North Woods who would split a case. I think you have a hell of a moose gun there.
There is hope, even when your brain tells you there isn’t.
– John Green, author
21 August 2006, 10:58
N E 450 No2Nice double.
You might try contacting JJ Perodeau at
www.champlinarms.com for loading info.
I do not know much about Black Powder, but I have read one of the problems is that the current US Black Powders are not as "refined" as British Black Powder made "back in the day".
DOUBLE RIFLE SHOOTERS SOCIETY
21 August 2006, 11:55
Hog KillerI have read Sherman Bell's data that shows Goex made in their new plant(La?) is weaker than the stuff from the old location in Pa.
I use 4 1/4dr in my Parker 10ga. with 1 5/8oz of shot. FFg would give me mostly crippled geese that needed to be chased down and finished. After switching to FFFg, they were dead in the air.
I really like your double, looks like a lot of fun.
Hog Killer
IGNORE YOUR RIGHTS AND THEY'LL GO AWAY!!!
------------------------------------
We Band of Bubbas & STC Hunting Club, The Whomper Club
23 August 2006, 09:39
KynochBill/Bob
According to Graeme Wright, page 86 2nd ed of "Shooting the British Double Rifle"..."Use a small amount of smokeless powder over the primer; e.g. SR4759, IMR 4227 or perhaps a shotgun powder. One grain of smokeless powder (SR4759) is roughtly equivalent to three grains of black powder. Keep the amount ot smokeless powder in the load small. No more than 20% when using SR4759 - preferably less than 15%. Initially start by using a load equivalent to the original black powder load..."
This is mentioned for RIFLES only. Not sure if it applies to bore-rifles as well.
RE 3:1, If you add smokeless, this suggests that you need to take it into account on your "total" powder. I read this as adding 10gr smokeless is roughly similar to adding 30gr of black.
Bob, if you rifle is crossing, I'm fairly certain that this is an indication that your velocity is too high in this case. Nice gun by the way!!!
03 September 2006, 07:34
Omnivorous_BobThanks for all of the info and suggestions.
I tried 135gn of FFFg in plactic and brass cases today. MUCH better!

Shots printed 2.5" high and crossing by 1.5" or so at 30yds. I was short on time so only tried a few pairs, but this is a huge improvement (my worst previous loads crossed 14" at this distance!). They also burned quite cleanly; I doubt there would be a need for any smokeless. I'll tweek the charge next and see if that uncrosses'em.
I was initially a bit leary of using a faster powder but recently found an old DGJ article with pressure data from a 12 bore with 5 thru 10 drams of 3F that was much lower than I'd expected.
As a plan B I made a cotton-reel type 775gn conical mold last week but havent finished a sizing die yet. If the verrrry slow twist will stabalize them they should definitely uncross then.
Bob

DRSS
"If we're not supposed to eat animals, why are they made out of meat?"
"PS. To add a bit of Pappasonian philosophy: this single barrel stuff is just a passing fad. Bolt actions and single shots will fade away as did disco, the hula hoop, and bell-bottomed pants. Doubles will rule the world!"
03 September 2006, 08:26
Hog KillerGlad to hear that you have made some progress with your loads. FFFg is going to be about the only BP I use anymore. Except for my 1 1/2" bore cannon, it will still live on 2oz Cg and a 1/2oz of FFG.
Hog Killer
IGNORE YOUR RIGHTS AND THEY'LL GO AWAY!!!
------------------------------------
We Band of Bubbas & STC Hunting Club, The Whomper Club
03 September 2006, 08:29
Hog KillerCan you load 140grs of FFFg? Are you lightly compressing you powder load?
Hog Killer
IGNORE YOUR RIGHTS AND THEY'LL GO AWAY!!!
------------------------------------
We Band of Bubbas & STC Hunting Club, The Whomper Club
03 September 2006, 09:03
Omnivorous_BobHK,
I'm using Federal plastic and RMC brass cases w/Fed 209A primers. Over the powder a thin cardboard cup wad (similar to what Sherman Bell used in an 8 bore article a few years back), then a 1/8" card, 1/2" fiber wad, dab of wonderlube, and then the ball. I give a firm push on the dow I use to seat the cup wad and the card that each slightly compress the powder. I've got more room in the brass cases due to the lack of a roll crimp and have easily fit up to 165gn Fg with a different wad column, with dismal results. With the brass cases I can get another 10-15gns in without any changes; in the plastic I think I would have to shave the fiber wads a bit. I'll try 145 and 150gn next and see if that does the trick.
I mostly use Fg for just low vel. 'plinking' rounds in my single shot anymore myself, and was never able to determine any difference between FFg and cartridge in my guns. Also, I would love to see a picture of that cannon some time!
Bob
DRSS
"If we're not supposed to eat animals, why are they made out of meat?"
"PS. To add a bit of Pappasonian philosophy: this single barrel stuff is just a passing fad. Bolt actions and single shots will fade away as did disco, the hula hoop, and bell-bottomed pants. Doubles will rule the world!"
03 September 2006, 17:37
Hog KillerBob, here you go.
200yd, 3 shot group
Exit of 100yd shot through 1/4" plate.
Hog Killer
IGNORE YOUR RIGHTS AND THEY'LL GO AWAY!!!
------------------------------------
We Band of Bubbas & STC Hunting Club, The Whomper Club
03 September 2006, 21:33
Omnivorous_BobNow
THAT is cool!

Bob
DRSS
"If we're not supposed to eat animals, why are they made out of meat?"
"PS. To add a bit of Pappasonian philosophy: this single barrel stuff is just a passing fad. Bolt actions and single shots will fade away as did disco, the hula hoop, and bell-bottomed pants. Doubles will rule the world!"