double barrel rifle - trouble shooting help

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FishHog

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So my dad used to make muzzleloaders. I inherited one that I have always loved that is an over/under swivel breach flintlock. The idea is you fire the top barrel, half #### the hammer, swivel the barrels to the other one and have another shot.

I thougth it would be fun to hit the deer woods this year with that gun. Problem I'm having, is both barrels are igniting at the same time. Kicks like hell, and unfortunatley isn't that accurate when both fire.

There is not a noticible delay between the second barrel going off, which seems odd to me, as I would think that if the ignition of the first pan is somehow wrapping around the barrels and igniting the second barrel, I would be able to sense that delay.

Last night at the range I tried sealing off the second pan with some bore butter, hoping it would stop the ignition of it. No luck.

so then I decided not to prime the second pan, figuring I could swivel and prime fairly quickly for that second shot if I needed it. No luck there either, the second barrel still fired.

I find that hard to fathom. Sometimes its hard to get flintlocks to fire in the first place, let alone somehow have the ignition moving to the far side of the gun, through the closed frizzen and igniting through the flash hole.

I'm almost thinking that the shock of the first barrel firing is auto igniting the powder in the bottom barrel, but is that really possible with black powder?

Hoping someone here can shed some wisdom. Otherwise I'm just going to hunt with a single barrel precussion gun that I made when I was a kid, under my dads instruction.

thanks,

FishHog
 
You could try a plug in the lower barrel's vent. That coupled with an unprimed pan and closed frizzen should just about guarantee that ignition isn't happening through the touchhole.
Does it make a difference which barrel is on top? Does this only happen one way, or both? Does it happen all the time, or only occasionally?
You might want to tear the gun down, see if anything is going on with the breechplugs.
 
good idea, I will do that.

No, does not matter what barrel is first, and it happens almost everytime. 90% anyway.
I've had it apart, and all appears fine in the breach area.

thanks for the suggestion.

FishHog
 
doubling

It may not be obvious, but my suspicion is that there is a leak at the breech - Remember that pressures are a lot higher when the rifle fires, and a tiny bit of flame might be getting pushed through.
 
oldstarfire said:
It may not be obvious, but my suspicion is that there is a leak at the breech - Remember that pressures are a lot higher when the rifle fires, and a tiny bit of flame might be getting pushed through.
Click to expand...

Thats a big possibility, I think the best way to test that is to immaculately clean both barrels,

load one with a nice stiff load.

The other "must be perfectly clean" load it with white Kleenex no powder just ram down the white Kleenex and plug the touch hole "vent"

Shoot the un Kleenex barrel a couple of times.

Pull the Kleenex from the unshot barrel, if there's leakage between barrels the Kleenex will have noticeable residue/scorching.

Aside from that try putting a small piece of hockey tape over the secondary vent when shooting, swing the unshot barrel into position pull off the tape, prime and your ready for your 2nd shot..
 
I think that I would join the others in suspecting that the breach plugs are loose and leaking or that there is something internally wrong. I cannot imagine the gun firing with no priming and the frizzen closed.
Just occurred to me; how tight is the pivot area? Are you getting powder in the pivot and that is flashing accross. Try priming with 3F or even 2F in the hopes of preventing any powder in the joint. Even so I still come back to thinking there is a leak between the two barrels.

cheers mooncoon
 
you could (when you clean it ) put water in one barrel
if it comes out the other barrel flash pan you have found your problem (or know where to start looking
 
so I finally got back to the range to do some more testing. I put some clean patches down one barrel and plugged the vent hole. Put a heavy load in the top barrel and shot. Removed the patches and they were clean, so I'm sure there is no crossover between the barrels (ie leaking breach plugs).

I've been shooting 275g conicals with 90g FFFg trying to get sighted in for deer season. My dad always shot round balls, but I've never been satisified with 45cal round balls for deer.

I loaded both barrels with balls and 90g of power and it shot fine, one barrel at a time. So I then loaded the bottom barrel with 40g and a ball (just to minimize the abuse on me when both go off), and then a conical and 90g in the top. Again both barrels would fire. So I started backing off the charge with the conical and found that 65g or less, and I had good reliability and only had one barrel would go off at a time. Anthing over that and they would both fire.

Again I didn't prime the bottom pan, but it would always go off if I was over 65g of powder.

I'm pretty sure that is it just a matter of a heavy conical taking longer to exit the barrel, and a lot of flame coming out of the vent and I guess wrapping around and causing the second barrel to fire. But I still find that hard to believe in a way.

Is there anyway that black powder is sensitive enough to ignite due to the impact of the top barrel going off? This is older powder if that matters, but its always been stored properly.

I'm coming to the conclusion that I won't hunt with this gun, but do you think 65g of FFFg behind a 275g conical would be a suitable hunting load. I've always used 85-90g in my other guns, but perhaps that is overkill (no pun intended). I hunt thick bush, so 50yrds is about the max shot distance I need.

Just looking for some thougths. thanks for the help guys.

FishHog
 
Realize that the traditional "Proof Load" for a round ball rifle was/is 2 patched balls over a double charge of powder. My 45 cal longrifles are most accurate with 70 gr. FFFg and a .445 RB that weighs nominally 130 grains. On that basis you are shooting almost proof - pressure loads using 90 gr FFFG and a 275 gr. slug. On that basis I have to believe you are getting flash leakage between the barrels at the breech and, given the breech pressures involved, you won't likely expose the situation by pouring water into one barrel and seeing it leak to the other - you might try plugging one flash hole and partially filling that barrel with low viscosity penetrating oil or Varsol and then looking for seepage into the other barrel. Failing that - just stick with the traditional RB loads - certainly my RB 45's have proven effective for deer to 100 yd with 70 gr. FFFg.
Good luck.
 
Did you try loading both barrels and plugging the vent on the off side? Currently it sounds like the flash wrapping around the barrels and while the amount of flash is not surprising, the wrap around combined with the configuration of the barrels seems strange

cheers mooncoon
 
mooncoon said:
Did you try loading both barrels and plugging the vent on the off side? Currently it sounds like the flash wrapping around the barrels and while the amount of flash is not surprising, the wrap around combined with the configuration of the barrels seems strange

cheers mooncoon
Click to expand...

I didn't actually, but will next time I get to the range. In a way, it won't matter, as either way, I can't load up both barrels with a double shot. If it would just shoot both accurately, it would be a deer killer, but they seem to fly wild (or the shoorter flinches too much) when both fire.
 
FishHog said:
I didn't actually, but will next time I get to the range. In a way, it won't matter, as either way, I can't load up both barrels with a double shot. If it would just shoot both accurately, it would be a deer killer, but they seem to fly wild (or the shoorter flinches too much) when both fire.
Click to expand...

In a sense it does matter because flashover is a nuisance, a breach leaking into the other barrel under heavy charges is an indication of something pretty seriously wrong

cheers Doug
 
Obviously both shouldn't fire - it would be really worthwhile to find out exactly what is going wrong. The rifle can be used as s single shot, but it would be nice to be able to use it as intended.
 
Not sure how those are put together or how the mechanism works for the swivel but personally I would be a bit uncomfortable shooting it like that. Seems unlikely to be just flash if it happens that regularly...

I would take it apart as far as possible (without removing the breach plugs initially) and look for signs of gas escaping from the breach someplace.
 
well I did a complete dismantle last night and there was powder residue in places that would indicate the breach plugs were leaking. Cleaned everything up as much as I could, then put the barrels vertically in a vice, plugged the vent holes and put WD-40 down each barrel. It took a minute but eventually both breach plugs dripped. One worse than the other.

So when it was made, the breach plugs were put in then filed flat at the base. There is a tapped hole right in the centre where the barrels meet which also included part of each breach plug. The swivel bolt threads into this hole. There is no way to remove them easily, and even if I get them removed, I'm sure I would have to rebuild it with new breach plugs as I'm not sure I would ever get them lined up exactly again. I'm sure a picture would help a lot, but I hope that makes sense.

I'm thinking I have 3 options.
1. make it a wall hanger and don't shoot it again (not really my favourite choice).
2. Remove the breach plugs (probably destroying them in the process and try to rebuild with new ones. (I'm sure I can do this, but it will take some work)
3. somehow seal the plugs that are there. Still brainstorming on this one. The only thing I can think of is to mig weld around them, then file them flat again. Not sure I want to go that route.

any thougths?

If I was somehow able to get the breach plugs out without destroying them, what could I use to seal them up if I could reinstall them and get them lined back up properly?

thanks for the help and ideas guys. I have decided that I won't be hunting next week with blackpowder, so I have a year to get this figured out and ready for the next season.

FishHog
 
The plugs were installed, and then filed flush with the face of the barrel breech? No extensions or lugs to engage with a wrench to unscrew them? After the plugs were installed, they were faced off flush with the barrel, and then the adjoining edges of the barrels and plugs were drilled and tapped and the pivot axle installed?
Usually a fine chisel cut is used to make reference marks, so that plugs can be removed and re-installed correctly indexed. But if there the plugs were installed in a semi-permanent manner, that is a problem. I don't know if a thread sealant would be a fix, or if a rebuild would be the only solution.
 
if the barrels twist is set up for round ball, your likely not going to hit the broad side of a barn using conicals. RB twist rate is generalt 1-60 to 1-72, WAY to slow for conicals, and dont even look at sabots.

so it flashes over with no proming mixture, clenexes are clean when pulled out of the second barrel. and it still does it when the second pan is sealed with bore grease.

if its not slipping past the breech plugs then im not exactly sure how its possible for it to ignight with the flash hole plugged.
 
tiriaq said:
The plugs were installed, and then filed flush with the face of the barrel breech? No extensions or lugs to engage with a wrench to unscrew them? After the plugs were installed, they were faced off flush with the barrel, and then the adjoining edges of the barrels and plugs were drilled and tapped and the pivot axle installed?
Click to expand...

yes exactly. That is the downside of a swivel breech. They need to be flush at the breech to swivel. I'll try to get pictures if I can. But yes, they were not meant to ever be removed, but now that they are leaking, I'm kind of stuck.
 
Aries- said:
if the barrels twist is set up for round ball, your likely not going to hit the broad side of a barn using conicals. RB twist rate is generalt 1-60 to 1-72, WAY to slow for conicals, and dont even look at sabots.

so it flashes over with no proming mixture, clenexes are clean when pulled out of the second barrel. and it still does it when the second pan is sealed with bore grease.

if its not slipping past the breech plugs then im not exactly sure how its possible for it to ignight with the flash hole plugged.
Click to expand...

Actually I did confirm last night that it is slippling past the breech plugs.
As for the conicals, I've actually been impressed with their accuracy out of barrels with a 1:60 twist. Certaily not as accurate as RB's, but very acceptable for a hunting load.
 
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