Pyrodex “P” High Pressure Cylinder Over Rotation…..

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Tenring

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Hay all just figured I would try some Pyrodex P I had on hand to use just in case I need to use it some day and do some test, here go’s I have an old beat .36 Navy but it still locks up good and tight. So I tried 15 gr. Of pyro and it worked ok then I tried 18 and 20 gr. And that went well so I gave her 25 gr. And she didn’t like that , cylinder was not wanting to index correctly after the shot the hammer would fall almost between the nipple notch to the far side of the cylinder. Because of to much pressure. Over rotation and advancement like she could not catch up. My general description of this is kinda well you know but I hope you get the jest of what I am talking about. I never had this kinda thing with just BP because Pyrodex causes to much pressure. I am not going to say I don’t like it just would have to keep the charge to a minimum I guess. It burned clean, this is my first time using fake stuff, since I was 13 Regular BP is all I have ever shot in my muzzleloaders and Precusion pistols. What do you guys think of this high volume Pyro test…P.S. I am open to all kinds of criticism and embarrassment.
 

rodwha

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I’m wondering if the flash channel through your nipples are too large. It’s a part of why Colt shooters replace the nipples from what I’ve gleaned, that it also ejects spent caps into the lock work.
 

bluemule66

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yep, check the nipples. I have shot lots of pyro-p and RS. works like black powder. The only time I have had a hammer blow back was because I should have changed the nipples sooner.
 

45D

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It may SEEM to lock up tight but . . . it definitely isn't right (I would suspect bolt head engagement, spring pressure and/ or combination of both). Everyone should look at it from the other end . . . why can't I shoot max charges from my Army, Navy Walker/Dragoon ? Not from a " my car drives great as long as I don't go over 40 mph"!! That just ain't right! SOMETHING'S WRONG!!!
Personally, you can't put enough bp (or any "subs") and a ball in a cap revolver to have " too much pressure " . . . much less a .36 cal.!!! I'd be laughed at if my car couldn't go over 40 mph LOL!!! If "nipple erosion" is the culprit, fine but if not, SOMETHING IS WRONG!! LOL. I always start at max charges and work down to the "sweet spot" (C&B or cartridge!).
So, it's not the propellant used, it's a problem with the "vehicle" it's used in!

Mike
 

Zapadach

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I have learned if you do not have hammer blowback, to keep the spent caps from falling into the lockwork, file a thin line about the thickness of your finger nail at 3 o'clock on the nipple where you would put the cap. Make sure the line is very shallow, only deep enough to barely catch your nail as you scrape across it. When the cap ignites pressure will travel through that thin channel and split the right side of the cap's skirt, thus causing the spent cap to fall clear of the action when the cylinder rotates. This will save you from having to buy after market nipples.
 

TrapperDude

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I run 30gr of Pyrodex P in my .44 Remington 1858 and haven't had hammer blow-back whether using the original nipples or the Slixsprings nipples. I have to agree with @rodwha and @bluemule66 about your nipple openings being too big. It might be time to change them out.
 

Tenring

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I have not tried Pyrodex out of anything but the above mentioned pistol but I can run a full MAX Charge out of all my pistols including this old .36 with REAL BLACK POWDER and they all run like new clocks zero problems and zero cap jams, this is why I posted the thread. Maybe I should have been more clearer. But the pistol I did the test on is still running the old original Uberti Nipples but it doesn’t do this with BP I am perplexed.?????
 

jsb30

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Sounds like blow back thru the nipple is partially cocking the hammer which causes cylinder to rotate . As hammer does go far enough to catch sear it falls back forward ending up between the nipples.
 

TrapperDude

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I have not tried Pyrodex out of anything but the above mentioned pistol but I can run a full MAX Charge out of all my pistols including this old .36 with REAL BLACK POWDER and they all run like new clocks zero problems and zero cap jams, this is why I posted the thread. Maybe I should have been more clearer. But the pistol I did the test on is still running the old original Uberti Nipples but it doesn’t do this with BP I am perplexed.?????
Some of the experts can chime in, in response to this theory, but what I have read is that Pyrodex burns at a higher temperature than real black powder. Maybe the higher temperature causes the pressure to stay higher for a bit longer than real black powder.

It's been 22 years since I took physics as an undergrad, so if we have any engineers here, please correct my work.

Work (W)= Force (F) * Displacement (D)
Force(F)= Mass(M) * Acceleration(A)
D = Velocity(V) * Time(T)

So,
W=F*D
F=M*A
D=V*T

We can substitute M*A for F in our equation for work, and we can also substitute V*T for D in our equation for work. That gives us a Work equation of:
W=M*A*V*T

If we have a higher Time (T) value, we'll get more work. What that means for the hammer of the OP's revolver is that black powder's gas jet from the nipples is exerting a certain amount of force for a given amount of time, but the amount of time it exerts the force ahainst the hammer is less than the amount of time the Pyrodex gas jet exerts force against the hammer. Therefore, the gas jet from the black powder peters out before the hammer moves far enough to rotate the cylinder, while the gas jet from the Pyrodex lasts long enough to keep pushing the hammer until the cylinder stop disengaged, allowing the cylinder to rotate.

It sounds like you have either or a combination of nipples that are open just a smidge too much or a mainspring that needs cranked down a bit to resist the hammer being cocked back from the gas jet.

As to my theory about how long the pressure is sustained vis-a-vis Pyrodex vs. black powder, any expert can correct that theory, too.
 

45D

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Ooooor, install a cap post and you can keep your "possibly" too light of a main spring!!! Heck - you can even lighten the main to give you about a 4 pound hammer draw which only enhances the shooting experience (less work per shot!!) It also . . . allows you to change cones when you get good and ready to!!

Mike
 
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sussexmuzllodr

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Hay all just figured I would try some Pyrodex P I had on hand to use just in case I need to use it some day and do some test, here go’s I have an old beat .36 Navy but it still locks up good and tight. So I tried 15 gr. Of pyro and it worked ok then I tried 18 and 20 gr. And that went well so I gave her 25 gr. And she didn’t like that , cylinder was not wanting to index correctly after the shot the hammer would fall almost between the nipple notch to the far side of the cylinder. Because of to much pressure. Over rotation and advancement like she could not catch up. My general description of this is kinda well you know but I hope you get the jest of what I am talking about. I never had this kinda thing with just BP because Pyrodex causes to much pressure. I am not going to say I don’t like it just would have to keep the charge to a minimum I guess. It burned clean, this is my first time using fake stuff, since I was 13 Regular BP is all I have ever shot in my muzzleloaders and Precusion pistols. What do you guys think of this high volume Pyro test…P.S. I am open to all kinds of criticism and embarrassment.
Its all in your mind...
 

Tenring

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TrapperDude and jsb30 have boiled it down, I new I would find the answer here. Thanks for every ones input I really mean that. Right on…
 

45D

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54ball, you need a better brand of oil!! Lol

Mike
 
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Larry P

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I have used prodex since 1976 and it has always worked well for me. I have no rusted barrel guns nor actions on any of my pistols or rifles. What I like most is on my revolvers I can shoot all day without cleaning my barrels and can still see the rifling at the end of the day. Try doing that with black powder. I don't care what you like be happy with what you like. After each session at the range I completely disassemble and clean throughly so no rust.
 

Tenring

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Like I said in my original post Larry I find no fault with Pyrodex it’s clean and it was one of my easiest clean ups I have had in awhile, The pistol problem I am having is probably nipple related no doubt. But I would shoot it if I had to , that’s why I did the test because I think changes are a common. Be cool.
 

TrapperDude

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But I would shoot it if I had to , that’s why I did the test because I think changes are a common.
It's why I bought three pounds of it earlier this year, even though I still have a good bit left from the first pound before those. As soon as I saw that BP revolvers and percussion caps for them were getting scarcer than ever before, I decided it was time to get ahead of the game on Pyrodex P.
 
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