Burnt Trigger Finger

[eccentricjackal]

Hi All,

I have a Ruger Old Army that I have started shooting more frequently recently, and found a recurring issue with hot flash flying out of the trigger opening and burning my finger!

From the lovely speckled burn pattern across my finger (not serious burns, just very off-putting!) I would guess it is specks of burning powder that is getting me. I had been using CCI caps, 20gn BP with ~18gn cornmeal and a greased wad under the ball, and was getting burnt once every 2 or 3 cylinders, I have just switched to a different brand of caps (can't recall brand at the moment) and it is now happening multiple times per cylinder...

When I bought the pistol it was used and neglected, with knackered nipples so I changed them for some Uberti ones of the same thread (but a little shorter I believe) that I had spare, so I was wondering if it might be an issue with those? If I am replacing the nipples is it better to go original Ruger or aftermarket? Here in the UK Ruger and Slix-shot are roughly the same price.

Any help is appreciated.

Ryan

 

[whughett]

Weird, strange, I feel bits of debris speckling my hands and on occasion my cheek, but never any one source I could put my finger on, pun intended. Looking at my ROA I suppose flame could travel into the bolt opening and thus out of the trigger opening, seems far fetched though. No cracks in the cylinders wall, are there.

 

[sltm1]

It might be the shorter nipples, but my guess is that the cornmeal is the culprit. Try shooting with out the filler and see what happens.

 

[rodwha]

I have a ROA and have shot everything from 25-45 grns (add 2-3 grns for weight as I use a rifle measure - 45 grns is highly compressible Triple 7) of 3F but have never had this happen.

 

[Mk VII]

I went with the Tresco ones from http://www.roaring-forties.co.uk/home/black-powder-accessories-broad-band and never looked back.

 

[eccentricjackal]

Thanks for the suggestions, I'll give it a try without the cornmeal and see if that stops burning me.

I forgot to mention in the original post; Is it normal for the caps to be just... gone after firing? The CCI caps I used before would be knackered, flat things, and occasionally get caught in the action, but the new ones must be broken completely and dropping out of the way?

Ryan

 

[jaguarxk120]

Could be the flash hole size in the nipple causing your burns.

Too large a hole and you will start getting blow back.

 

[eccentricjackal]

Would blowback break the caps to bits after firing?

Ryan

 

[daboyleroy]

About 20 seconds into the video you can see the 1858 Remmie's hammer bounce back a bit. I think it is due to pressure building in the chamber, not the cap pressure, that causes the little backward movement. Others think it is caused by the hammer hitting the frame and bouncing back. I have never owned an 1858 Remmie so I don't know.

http://www.sassnet.com/forums/index.php?/topic/260465-percussion-cap-blowback/

 

[DD4lifeusmc]

If you believe it is coming up through the trigger hole.
remove trigger guard and fill the cavity with bore butter.
It will stop the flame or specks from coming through
I fill that area on all of my pistols, mostly to keep residue from getting in.
So I only have to clean that every couple years

 

[whughett]

If you believe it is coming up through the trigger hole.
remove trigger guard and fill the cavity with bore butter.
It will stop the flame or specks from coming through
I fill that area on all of my pistols, mostly to keep residue from getting in.
So I only have to clean that every couple years

Good idea but bore butter becomes liquid at too low a temp. A Walker back from the GoonGunWorks has its trigger cavity packed with Mobile1 grease, a synthetic grease. Hot humid summer days and enough rounds to make the cylinder and barrel hot and no run out at trigger, bolt or hand openings.

 

[whughett]

About 20 seconds into the video you can see the 1858 Remmie's hammer bounce back a bit. I think it is due to pressure building in the chamber, not the cap pressure, that causes the little backward movement. Others think it is caused by the hammer hitting the frame and bouncing back. I have never owned an 1858 Remmie so I don't know.

http://www.sassnet.com/forums/index.php?/topic/260465-percussion-cap-blowback/

The hammer seems to be moving back before any signs of the main charge firing. As Newton said, for "every action there is an equal but opposite reaction". The cap detonating has enough force to overcome the mainspring and move the hammer back, even before the flame column reaches the main charge. That's just one gun with one main springs force, and I couldn't see it on all the shots.

 

[DD4lifeusmc]

yes I know BB is pretty thin.
It doesn't get that hot here in Wyoming, so I suggested it.
I would venture to say most muzzleloaders have it on hand, where as not everyone would have a tub of grease

 

[jaguarxk120]

The hammer seems to be moving back before any signs of the main charge firing. As Newton said, for "every action there is an equal but opposite reaction". The cap detonating has enough force to overcome the mainspring and move the hammer back, even before the flame column reaches the main charge. That's just one gun with one main springs force, and I couldn't see it on all the shots.

The main charge has fired, the bullet/ball hasn't started moving yet. Pressure builds up and a jet of gas forces the hammer back.
The pressure continues to build and forces the ball out of the chamber and into the forcing cone down the barrel.

 

[whughett]

The main charge has fired, the bullet/ball hasn't started moving yet. Pressure builds up and a jet of gas forces the hammer back.
The pressure continues to build and forces the ball out of the chamber and into the forcing cone down the barrel.

Not quite sure it works quite that way with black powder. Smokeless yes, its a controlled burn, black is an explosion, it releases its energy all at once. But I'm way out of my league here, just know that hammer is moving back with no fire present. The cap is sitting over an empty tube, the cone, with two holes one very large, on very small, the energy of the caps can move two ways and its overcoming the resistance of the back spring to hold the hammer down.

 

[.308 Norma]

About 20 seconds into the video you can see the 1858 Remmie's hammer bounce back a bit. I think it is due to pressure building in the chamber, not the cap pressure, that causes the little backward movement. Others think it is caused by the hammer hitting the frame and bouncing back. I have never owned an 1858 Remmie so I don't know.

http://www.sassnet.com/forums/index.php?/topic/260465-percussion-cap-blowback/

Neat video! Thanks for posting it!

 

[daboyleroy]

Not quite sure it works quite that way with black powder. Smokeless yes, its a controlled burn, black is an explosion, it releases its energy all at once. But I'm way out of my league here, just know that hammer is moving back with no fire present.

https://www.thehighroad.org/index.php?threads/black-powder-vs-smokeless-powder.781476/

 

[jaguarxk120]

Not quite sure it works quite that way with black powder. Smokeless yes, its a controlled burn, black is an explosion, it releases its energy all at once. But I'm way out of my league here, just know that hammer is moving back with no fire present. The cap is sitting over an empty tube, the cone, with two holes one very large, on very small, the energy of the caps can move two ways and its overcoming the resistance of the back spring to hold the hammer down.

It is too bad that the video wasn't taken with a high speed camera, then you could see what is actually happening.

Also if what you say is correct then the hammer will bounce back with just the cap and a empty chamber.

 

[whughett]

https://www.thehighroad.org/index.php?threads/black-powder-vs-smokeless-powder.781476/

It is too bad that the video wasn't taken with a high speed camera, then you could see what is actually happening.

Also if what you say is correct then the hammer will bounce back with just the cap and a empty chamber.

Good point, wonder if it does indeed.

 

[J-Bar]

hot flash flying out of the trigger opening

The only opening on the inside of a Ruger Old Army frame that could conduct hot gas to your trigger finger is the hand slot. The hole for the bolt is blocked by the locked bolt itself. If so much hot gas could come backwards through the opening for the hammer, follow the hammer body back down into the gun and then out the trigger opening (a very complex path which is mostly blocked by the hammer and hand anyway) I expect you would be getting facial burns as well.

Edit: I previously said the Uberti nipple would not fit in an ROA cylinder without modification. I was wrong. I tried swapping the nipple from my Uberti 1851 into the ROA cylinder and it went in. Apologies. A Pietta nipple will not fit, however.

A percussion cap does not generate enough pressure to move the hammer backwards, as this video proves. This discussion has come up before and I made the demonstration video myself. Blowback of the hammer through the nipple vent occurs when the main powder charge ignites, not the cap. The cap generates enough pressure to fragment the copper cap body, but not enough to blow the hammer back and release the cap from the nipple cone. The particular gun in this video has hammer springs that are lighter than factory springs, so if blowback from a cap alone could occur, it should show up. It doesn't.



I don't think it has anything to do with filler in the chamber. Those of us with unmodified Old Armies can shoot very heavy charges without significant gas leakage occurring.

Edited:

It's hard for me to imagine you are getting so much blowback to cause the gas to leak all the way down to the trigger. If that is occurring and the inside of your revolver's frame looks ok, then your nipples should be replaced.

Here are some additional photos of my ROA to compare with yours. See if your cylinder and the inside of your frame look the same as mine, which has not been modified in any way. You can see that any blowback from the nipple is directed upwards, causing the black discoloration above the hammer nose. The baffles around the nipple don't allow much blowback to go anywhere else. Are those baffles intact on your cylinder?

 

[Jim K]

In my limited experience, a C&B revolver blowing the hammer back is due to an enlarged flash hole in the nipple.* (It is rare, but once in a while you will actually get such a gun to double, the back blast being enough to cock the hammer and turn the cylinder!) That is why one needs to check the nipples every so many shots and replace those that are burned out. I had not seen, or perhaps not noticed, the condition the OP mentions, but if enough gas comes back through the nipple to blow the hammer back, some can easily get into the interior of the frame and then exit through the hole for the trigger.

*Note that I mean the size of the FLASH hole, not the size of the nipple. In the picture, only the left had nipple has the proper size hole - the others are oversize.

Jim

 

[jaguarxk120]

Why not remove the nipples and show the other side where the flash hole is.

Better still if the OP showed the nipples he is using.

 

[J-Bar]

Why not remove the nipples and show the other side where the flash hole is.

Better still if the OP showed the nipples he is using.

You mean like this:

That is a Pietta nipple on the left, factory original Ruger Old Army in the middle, and a Treso that fits my Uberti 1851.
Even though the Treso has a dramatically smaller flash hole than the others, none of them are big enough to cause hot gasses to exit by the trigger.
Since the OP said the gun had been "knackered", it made me wonder if there was something abnormal about the cylinder or inside of the frame; that is why I posted the other photos to allow a comparison. The Treso nipples in the ROA cylinder have the same size flash hole as the one for the Uberti 1851.

 

[eccentricjackal]

Thanks for the replies, and thanks J-Bar for the pictures, I didn't have internet access over the weekend so have only just seen these replies.

The pictures are very helpful, and I will look properly over them and compare them to mine tonight, I have never noticed the hammer bouncing as in the video above, but equally have never looked for it either. I've never had burns anywhere but the tiny bit of my finger that is sat on the trigger, no blowback towards my face or arms.

When I said knackered I was being harsh, the previous owned had attempted a DIY brushed steel finish on a stainless gun, leaving the finish a mess, and had failed to properly clean leaving light pitting in the barrel and surface rust inside the action. The nipples had flash holes large enough that powder fell through when loading, either from botched 'enhancing' or from rust/neglect, and that's why I swapped them out for the alternate ones. I rarely throw anything out so probably still have the old nipples somewhere if I want to test them again.

Thanks again,

Ryan

Edit; I'll get to the range this week to try out the borebutter in the action idea, it would at least tell me for sure where the heat is coming from if it stops it!