Converting from #11 Cap Nipple to Musket Cap Nipple - Help!

[YippeeKiYoRed]

For reference the firearm in question is a Lyman Plains pistol 50-cal and the powder is Triple7 FFG.

Was able to acquire some 4-wing musket caps and thought it'd be a simple nipple swap. Bought a musket cap nipple from Track of the Wolf. The musket nipple was taller than the #11 nipple so I shortened it to get a flatter hammer strike. Tried it but no bang. Tried 3 times. Caps fired but powder never did. Swapped to a #11 nipple and then the gun worked right away.

Shortening the nipple might have shrunk the inlet hole so this evening I enlarged it slightly with a counter-sink. The musket caps' flame hole was also smaller. Maybe 0.030" compared to about 0.040" for the #11 nipple. So also drilled out the flame hole to 0.040" using a #60 drill bit. Have not tried it since making these modifications. Also could be the hammer is still not striking flat enough which is allowing flame to escape out the side.

Any advice from any successful conversions from #11 to musket cap? Where did you get your musket nipple?

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[Andy54Hawken]

I have never had any luck with 777 Powder.
With my experience I would say the powder used is playing a big role here.

I would suggest using actual black powder.
Andy

 

[YippeeKiYoRed]

I have never had any luck with 777 Powder.
With my experience I would say the powder used is playing a big role here.

I would suggest using actual black powder.
Andy

Thanks.

 

[osprey]

I recall reading that the #11 caps actually provide a hotter kernel of spark than musket caps, so perhaps this is what you have experienced.

 

[RVTECH]

The musket nipple was taller than the #11 nipple so I shortened it to get a flatter hammer strike.

How much taller was the Musket nipple over the #11? And - did you try it before shortening it?

Many moons ago when I was 'early' into ML I was experimenting with modifying nipples when I was experiencing FTF cap issues as well.

One thing I noticed is the 'angle' of the nipple stem needs to be specific in that the cap has to fit snugly but 'seat' all the way down with minimal finger pressure. If the taper of the nipple stem is such that the cap presses on but does not seat completely the hammer strike will push it further down and in effect 'cushion' the hammer strike and not necessarily ignite the cap. I actually had some caps 'bulge' on the nipple stem and I had to pry them off.

Also nipple flash hole diameter is important as well. I once drilled out a # 11 nipple and while the caps fired routinely I was getting inconsistent ignition. I attributed this to the larger hole allowing the flame to 'widen' out and therefore not 'jet' through a smaller hole and concentrating the flame to the powder.

No experience with 777 myself but I have read about some having ignition problems with it. It has no sulphur and burns much slower than BP (more like smokeless actually) but with higher pressure so that may have something to do with 777s more difficult ignition.

 

[YippeeKiYoRed]

Thanks for responses. As one might guess this is being born of desperation. Musket caps showed up a month or two back so I bought a brick since #1 caps were/are nowhere to be found.

True blackpowder might be worth trying but don't have any right now.

RVTECH wrote " If the taper of the nipple stem is such that the cap presses on but does not seat completely the hammer strike will push it further down" Yep. When shortening it I also reduced the diameter slightly so the cap would still fit.

Will try again this week or next.

 

[RVTECH]

When shortening it I also reduced the diameter slightly so the cap would still fit.

Which might have been ok BUT - was it so short the bottom of the cap did not rest on the 'mouth' of the stem? with possibly a gap you couldn't see ? This as well could cause a CAP FTF.

 

[YippeeKiYoRed]

Yes. Made sure it would seat all the way down.

The caps always fired. It was the powder in the barrel that never ignited.

 

[RVTECH]

I'd try some real BP - or at least some Pyrodex as an alternative. I switched to Pyrodex and really liked the results.

Pyrodex is very close to BP in that it is made from sulphur, charcoal, & potassium nitrate - with a few additional ingredients that seem to be kept about as secret as the Coca Cola formula!

And - just to make sure, drum and flash holes all clean and clear?

 

[YippeeKiYoRed]

Have made some progress after refining the nipple. Different firearm this time - a 50-cal rifle. Same powder. As mentioned before the flash hole seemed really tiny compared to other nipples so it was bored out with a #60 drillbit (0.040"). Made a few other refinements to the nipple. In the most recent test the cap itself didn't fire with every hammer drop. But when it did the barrel charge ignited every time and with very little delay. Per what @RVTECH mentioned there might still be an issue with the cap not seating down completely due to the diameter of the nipple. Since the nipples are tapered by shortening it that effectively increased the diameter. Also, the rifle is much older than the pistol and may have a weaker spring.

Would be easier if I had a lathe instead of chucking up the nipple in an electric drill held in a vise. I spend so much on rifles, scopes, etc. that $600 for a hobby lathe doesn't seem that much. But few on Amazon are highly rated. Hmm, no garage space either.

Not there yet but it's promising enough to keep pursuing. With a brick of musket caps on hand but very few #11's the conversion has to work if I really want to get some shooting done. I'll keep this thread updated.

 

[sikhed]

I recall reading that the #11 caps actually provide a hotter kernel of spark than musket caps, so perhaps this is what you have experienced.

 

[sikhed]

Don't think that's true, but have heard that too.
Like others, I had only a few hundred #11s, and 1k of Schuetzen musket caps.
So replaced a #11 nipple on a .54 rifle with an ampco musket one.
Same charge as before, but now the sidelock hammer would blow back to halfcock when shooting it.
Someone told me that the hammer blowing back is very hard on the lockwork.
Am considering swapping back to the #11 nipple, as I just purchased another K of them.