GPR FLASH in the pans

[d.thomson]

I just built a GPR in flint and shot it yesterday. I had alot of flash in the pans and hangfires. The touch hole is 1/16 but I noticed that the vent liner protrudes into the patent breach, could this be part of my problem. I was using 2f goex for prime and main charge, I didnt over fill the pan well bellow T.H. pan flashed every time but only banged 1 in 4 can any one help me out. I was thinking of drilling out the T.H. to 5/64. I also used the vent pick to open up the T.H. after I had the main charge in like Paul sugested. Thanks for any help F.K.

 

[MikeChapin]

You definitly want to file down the touch hole liner to where it is not protuding into breech. 2F will bridge over the patent breech sometimes when the rifle has been fired a few times and the liner protruding into the breech area just makes it worse. When it bridges there is a void space around the touch hole. I check with a vent pick and see if I can feel powder. If not, I push a little prime into the vent.

It sounds as if the lock is doing its part. On my rifles that use 2F I open the flash hole to 5/64. That has made quite a difference in those rifles I did it to.

 

[retired]

On my GPR the liner also extended into the powder well by almost 1&1/2 threads. Shortened and coned it then drilled it out to .070 (#50 drill) and things really improved. If .070 doesnt work then by all means go to 5/64 (about .078). Good luck.

 

[paulvallandigham]

Fisher King; You have already gotten some excellent advice on fixing that touch hole liner. Do it. If you are still having ignition problems, then begin opening the hole in the liner. Start with that #50 bit( .070") and see if that works for you. If not, go up in size. I ended up opening my liner to 5/64" and it stopped the hangfires. But get there in steps, as you don't want any bigger vent hole than is necessary.

 

[d.thomson]

Thanks guys I will do these thing but in increaments. Regards F.K.

 

[cowpoke1955]

Fisher,
I completed my GPR kit a couple of months ago. The first time out I had almost all flash in the pan and some hang fires. I drilled the vent to 1/16th and still had a lot of flash in the pan. I finally drilled the vent to 5/64th, as everyone here suggested, and now it goes off every time :thumbsup: .

 

[d.thomson]

Cool :thumbsup: :hatsoff: F.K.I think that will probably be the way to go.

 

[Old Salt]

Fisherking,

I recommend to avoid wiping between shots also. However if you feel the need to do so don't push the crud all the way down to the top of the patent breech. I found that a simple spit patch and no wiping helped with more consistent ignition on my GPR.

Old Salt

 

[Larry Pletcher]

Hi Fisher...,
I liked Paul's advice about sneaking up on the best diameter. Numbered bits available at any good hardware give you even more choices:

1/16 - .0625
#52 - .0635
#51 - .0670
#50 - .0700
#49 - .0730
#48 - .0760
5/64 - .0780

I don't recommend trying every one, but as Paul says, you don't want any larger hole that necessary for reliable ignition. My guess is that you will get good ignition somewhere in the #50 - 5/64 area.

Regards,
Pletch

 

[d.thomson]

Hi every one I drilled the T.H. to 5/64 coned the inside with a 1/4 drill bit and filed down the vent. no flash in the pans. I had to swipe about every 15 rounds. I still get a bit of delay from the pan to the charge. I was going to get a White Lightning vent and see if this makes a difrence. Has eny one had any experiance whith the white lightning? I'm going to the range tonight after work and bench it to see ware it is shoot ing and working up a load. Regards F.K. P.S thanks for all the help. :hatsoff: :thumbsup:

 

[MikeChapin]

I don't know if White Lightning makes one with a thread size for a GPR. I know that they use a finer thread than most of the other liners around. Changeing to one usually involves drilling out the old threads and tapping the new thread size.

 

[cowpoke1955]

Check your priming charge first. Make sure the pan isn't too full. Try FFFg and FFFFg. Once you drill out your vent hole for the White Lighting, it a lot of trouble to go back. On my .54 GPR I use 80 grains of FFg Goex, .530 ball and pillow ticking with moose milk. This combo plants them into one hole at 50 yards. I also used the primitive rear sight. It was too loose, so I peened the bottom of the sight. Figured better the sight than the barrel, in case something went wrong. It fits nice and tight now. Looks better than the adjustable sight too. Let us know how things turn out :thumbsup: .

 

[Rebel]

The only way to put a White Lightening in is to drill and tap for it. They don't make them in standard thread sies.

 

[paulvallandigham]

If that liner is the one made by Jim Chambers, with the parabolic cone on the inside, it will definitely help.

As to the delay in ignition, delays come at different times, depending on lock geometry, vent hold placement, and where powder is put in the pan.

With an empty gun, in a dark room, hold the gun out at arm's length, so you are looking at the lock from the side. Use your Left thumb to trip the cock, and throw sparks. Do the sparks get thrown into the pan directly, or do they roll down the face of the frizzen, and eventually fall into the pan? If the later, the problem is lock geometry, and the angle of the flint to the face of the frizzen is to " square ". If you don't already have them, you will begin to see gouges in the frizzen face at right angles to the length of the frizzen, where the edge of the flint is striking the face. Get a protractor at the grocery store for under $1.00. Lay the gun on its side, and place the protrator so that the center of the bottom line( where the hole is) is at the point where the flint touches the face when lowered. You want to grasp the gun and lock so your hand helps to hold the frizzen closed under the spring tension against the cock, so that your other hand can postion the protrator, and then use a straight edge to run from that center point up to the top of the face of the frizzen. The straight line should cross the outer ring of the protractor, and tell what that angle is. If its not 55-60 degrees, the flint is striking too square.

To fix; make a template on cardboard, using a heavy wide magic marker pen to give you the 60 degree angle you want the cock to strike the frizzen. My template shows the shape of the cock, and more importantly the angles of the cock screw as it goes through the lower jaw, with a line drawn on that axis down through the lower part of the cock. I show on the template the current angle of the lower jaw to this axis, and then draw in my heavy line to represent the new angle I want to achieve. When working on the cock, I can remove it from my vise, place it on the template, and check to see that I have achieved the angles I want.

Remove the cock from the lock, and remove the top jaw, cock screw, flint and flint wrap. Then using a propane torch on the narrow part of the goose neck of the cock, heat it to cherry red/orange, and use plyers to bend it forward to meet that template. With the thinnest point of the gooseneck heated this way, you should be able to bend the cock forward by putting pressure on the lower jaw of the cock, without resorting to using a hammer. If it won't bend, keep heating the gooseneck. You may want to enlist the aid of a helper to hold the torch on the gooseneck, while you are doing the bending.

The amount of bending required is very little, so don't use a lot of force at first. See just how much force is needed to move the metal before putting your weight on it.

When the bend is made, just let the cock cool in the air. It will take about 20 minutes for it to be cool enough to touch. If you leave it on a vise, or other heavy metal surface, it will cool much faster, as the metal will act as a heat " sink ". Clean off any scale that forms where you heated the cock, and touch up your browning, if that is how the cock is finished. Then replace the cock on the tumler, and put the top jaw, flint and wrap, and cock screw back in the cock. You should be ready to go.

We have previously talked about positioning the touch hole above your pan, so that the hot part of the flame from the burning powder is next to the hole, and about using a vent pick to open a hole in the powder. You may be allowing crud to build up in that gun by cleaning it only after 15 rounds or so, and that can cause hangfires, too. It all depends on how close the face of the breechplug is to that vent hole. If its really close, any buildup will block a portion of the hole, and inhibit ignition. Ideally, the face of the breechplug should be about 1/16 inch to the rear of the rear edge of the vent hole, so that crud build up does not cause hangfires. Since you did not make the gun, this is a hard thing to correct. However, you can clean between shots, and that should help eliminate those kind of hangfires. You just have to use the right jags, the right size patches, and learn how to adjust your stroke so that you are pulling the crud out, and not pushing it in.

If I waited 15 shots before cleaning, It would take me 5 or more patches to clean the entire length of the barrel, as I would want a very clean patch to get down to that last 2 inches of barrel to clean the face of the breechplug, and the chamber( which should have burned most of the crud out!) I do short strokes when I am cleaning a dirty gun barrel, never going more than 6 inches down before pulling the patch out and the crud in that section of the barrel with the patch. Then I change to a new patch for the next section. When I finally am down to that last section of the chamber, and the face of the breechplug, I slowly push the rod down, and then turn the jag clockwise, to clean off the face of the breechplug. Because the patch is not already full of crud, the cloth soaks up any crud on the face of the breechplug, and I can pull it out. If its particularly messy, as on high humidity days, I will then use a clean patch with moose milk on it, to dissolve the remaining crud down there. Then I use a couple of clean patches to pull out the solvent, and any crud, and dry the chamber, so I can load the next powder charge into a dry barrel.

When cleaing between shots, there is much less crud in the barrel to clean out, so I can get by with using only one or two patches, again using short strokes to clean the first 6 inches or so, then the next section, If I see a lot of crud building, I will either turn the patch over, or get a new patch. It all depends on the condition of the patch at that point. Being a cheap fellow, I tend to flip my patches over.

I found that if I did less, the gun would occasionally hangfire on me. I also found that cleaning the barrel between shots involved a lot less work, and a lot less problems to solve. But, I do go through cleaning patches, and that seems to be a problem for some shooters.

YOu can throw flannel cotton patches into a clothes net bag, and wash them in your washing machine( be sure to wipe up the grime and soot that will be in the tub when it finishes, if you want to be able to continue to live with your domestic supervisor!) and they can be dried and used again. I haven't done that, but I have known shooters who do. After a second or third use, they finally throw them away.

I hope this helps.

 

[d.thomson]

Thanks Paul that again was a verry thought out responce and one I will learn a lot from :hatsoff: . And thanks to every one else for the help, every bit of information is knowlage gained, it shure beets trial and error :thumbsup: Regards Fisher King.

 

[MikeChapin]

You might want to try a finer pan powder. I know a lot of people like to use 3F and 2F for priming but I have never had much luck with it. It might be my imagination but I can tell the difference. The coarser grained powder just doesn't seem as fast as 4F.

 

[Larry Pletcher]

You might want to try a finer pan powder. I know a lot of people like to use 3F and 2F for priming but I have never had much luck with it. It might be my imagination but I can tell the difference. The coarser grained powder just doesn't seem as fast as 4F.

FisherKing,

This is something you need to try. In 2005 I timed 6 different priming powders for an article in MuzzleBlasts (April 2005). Included were 4 samples of 4fg powder and samples of 3fg and 2fg:

Goex ffg
Goex fffg
Goex ffffg (before plant moved)
Goex ffffg (after plant moved)
Swiss ffffg
Swiss Null b (also ffffg grand)

Each was timed in 20 trials. The fastest 2fg time was slower than the slowest Swiss 4fg times. I understand the advantages of using larger grain sizes in very humid weather, but you need to at least give this a try.
Regards,
Pletch

 

[paulvallandigham]

Pletch: Come on, you should at least note that the difference in ignition speeds of the different powder granules cannot normally be detected by the human ear, and is measured in milliseconds. People tend to " get a hunch " that ignition is slower, because their brains cannot process information of that fine or fast a time sequence. We can easily see it on monitors, so You are correct-- Please, everyone, I am not disagree with Pletch about that fact- but its next to impossble to hear the difference. particularly when comparing FFFg with FFFFg. I will concede that even I " get a hunch " that using FFg makes for slightly slower ignition time in my gun, but not enough that I can move my front sight off the target during that interval. Isn't that is what is really important?

 

[Larry Pletcher]

Pletch: Come on, you should at least note that the difference in ignition speeds of the different powder granules cannot normally be detected by the human ear, and is measured in milliseconds. People tend to " get a hunch " that ignition is slower, because their brains cannot process information of that fine or fast a time sequence. We can easily see it on monitors, so You are correct-- Please, everyone, I am not disagree with Pletch about that fact- but its next to impossble to hear the difference. particularly when comparing FFFg with FFFFg. I will concede that even I " get a hunch " that using FFg makes for slightly slower ignition time in my gun, but not enough that I can move my front sight off the target during that interval. Isn't that is what is really important?

Hi Paul,
You are absolutely correct. In almost all of my articles and in my emails here I stress that human senses are not good enough to tell the difference. In fact the following is a quote from my priming test article in MB:

"Drawing conclusions after the experimentation requires great care. One conclusion deals with the comparison of priming and non-priming powder. While there was a significant difference, I could not discern this difference with human senses. Friends who report that their ignition with regular horn powder is just as fast support this. Their ignition is slower, I believe, but we cannot detect the difference without scientific means."

With all that said, if someone conplains about ignition with ffg priming powder, it does make sense to try ffffg prime.

As a side bar and after hearing and watching hundreds of trials with a computer, it is my opinion that a delay that can be heard is caused by a bigger problem. For instance we quibble about .0020 seconds on lock time and loose .02 with a poorly managed flint edge or a poorly maintained vent hole. If I hear a delay the first place I look is the vent hole.

Regards,
Pletch

 

[paulvallandigham]

Yes. I also look at several other problems first, before considering what powder is being used for priming a flintlock. Location and size of vent hole, as well as its condition, then lock geometry, and then condition of the flint. It usually is something like the guy doesn't clean between shots, or doesn't use his vent pick to poke a hole in the main charge thorugh the vent to give the flame from the priming powder access to more granules to light. I remember your article, and that is why I begged for the additional information. I don't want readers here to ever think that using 4F vs. 2F or 3F powder is going to make that much noticeable difference in ignition.