More ignition trouble with Lyman GPR

[Valley Forge]

I read the recent thread about trouble with igniting the main charge on a Lyman GPR. I am also new to Lyman GPR and am starting to have similar trouble. I got a new flintlock, .50 caliber GPR. I carefully cleaned the barrel before ever shooting it, as per the Lyman instructions. I am getting decent sparks into about 3-6 grains of GOEX 4Fg with a nice pan flash. I am using 50-60 grains (varies) of GOEX 2Fg down the bore, I smack the side of the stock opposite the lock after pouring in the powder. I load a .018 pre-lubed patch with .490 lead round ball, carefully seated tight on top of the powder. Follow a careful ritual to make sure I do not load without powder down the bore. When I first go out to the rnage, I get about 5 good shots and then the ignition problems start. I am cleaning the bore after every shot by taking a slightly damp patch and running it down the bore and then two passes with a totally dry cleaning patch. Then I pick the touch hole to make sure it is clear. Then I carefully brush the pan and area around the touch hole, and then I wipe the frizzen face and the flint edge with an alcohol prep pad, but do not let alcohol touch the pan or touch hole area. Loading the pan is done with anywhere from 3 to 6 grains, and I have tried covering the touch hole, leaving it uncovered, using 3 grains, using 6 grains, banking the pan powder away from the touch hole, etc. I have tried picking the touch hole after loading the powder and PRB down the bore, and I can feel powder "moving out of the way of the pick" so I do think I am getting powder down that far in the breach area inside the barrel. It does seem to actually make the ignition problem worse, not better to pick the touch hole after loading the main charge, but in any event there is no consistent ignition with or without picking the touch hole. I even tried using the pick to guide some of the 4Fg pan powder into the touch hole and into the breach area, as described in the other thread. No consistent ignition with or without that. I have not gotten a new touch hole liner. I might do that. I kind of doubt that Chuck Dixon would sell me a rifle that right out the door needs that kind of modification. But, then again, I am following his directions that he gives out, to the letter as best I can, and I am having this problem. Like I said, the first five shots seem to go well, then I have pan flash and lots of trouble igniting the main charge. I am buying a .32 caliber brash brush that I am going to try using between shots to clean out the breach area. Also, I suspect some will offer that I should not clean at all between shots because the cleaning patches are pushing crud down the breach hole. I guess I could try that, but it gets hard to load at all if I do not clean between shots. I'm thinking that running that .32 brass brush down into the breach after the cleaning patches should help to clean muck out of the breach area before loading the next shot.

I wonder if this is a clue: When I fire a shot, and then lay the rifle down, there is a little trail of smoke that comes out the touch hole for a little while. It is still smoking, gently, long enough for me to get the slightly damp patch and run it down the bore, maybe 2 minutes. Does that mean anything? I am wondering if it means collections of unburned powder, or residue or both in the breach area??? Am I on to something here or is that a red herring?

Thanks in advance for the help.

 

[Zonie]

Welcome to the Forum.

IMO the smoke coming from the vent is normal for quite some time after the gun has been fired.

As your guns problems don't show up until after you have fired 5 shots, that tells me it's something your doing that's causing the problem.

Your loading technique seems to be exactly what most of us would recommend right down to the slapping the side of the stock to jostle some loose powder into the small hole that connects the breech with the vent (the flame channel).

Your getting good flashes in the pan which indicates the flint/frizzen and pan prime are working as they should.

That leaves your bore wiping or the size of the touch hole as the most likely suspect.

I feel that the standard vent liner supplied by the large factories comes with too small of a hole in it. I feel the minimum hole size should be 1/16" (.0625") so I will suggest that you get a 1/16" drill bit to enlarge the hole thru the vent liner.

Getting to your wiping method, you say your using a "slightly damp" patch and that is as it should be. As you know it should not be "wet" because the water it leaves behind will wet the next powder charge if any water at all gets down inside the undersize powder chamber.

You didn't mention how long your waiting to retrieve the "damp" patch after pushing it down the bore and if you are not letting it sit at the bottom of the bore for at least the count of 5 before removing it there is a good chance that you are leaving quite a lot of semi hard fouling on the walls of the bore.

If a lot of fouling is left on the walls after removing the damp patch your 2 dry patches will knock it off and it will fall into the powder chamber where it will be blown from the powder chamber back thru the flame channel to the vent hole.
In this location the fouling can feel (and look) like loose powder when you pick the vent but as it is fouling it will shield the new powder charge from the flash of the pans priming.

Another thought is based on several different people on our site who have mentioned that when using 2Fg powder it seems to jam up in the flame channel with very little of it actually reaching the vent hole.
They have said that switching to 3Fg powder improved their guns reliability.

 

[longbow1]

Hello ,welcome to the fourm I shoot a GPR flint one question What kind of flint are you using. There are several kinds the gray saw cut agate then there are the hand knaped the hand knape either french amber or the english gray/black flint. Saw cut agate is not the best for flintlock shooting it will work for a few times but it dulls quickly and you need to change or reknapt it There are some who sell good flints that are on the site maybe they will chime in and help . :hatsoff: again welcome

 

[dckcrk]

I started the other thread you are referring to and I have started trying to find a solution. I drilled the touch hole to 1/16" and saw some improvement. Changing to 3F helped some to but the gun is still misfiring about 1 in 3 times. Much better than the 3 times out of 4 it used to have. I have just received the RMC replacement touch hole liner but I am not going to try it until I get through cussing the factory liner. Next step is using a #50 drill bit (.070) and I may go all the way to 5/64 before chucking the Lyman liner in the trash and installing the RMC. I'm stubborn that way.
Like you I am not having any difficulty getting the pan to ignite with any flint I have tried as long as the bevel is down. It just won't light the main charge reliably. Keep me posted on your progress and I'll do the same. Luckily the old Deerstalker is dead reliable in any circumstance.

 

[Larry Pletcher]

It sounds like you have tried a bunch of things to get this gun shooting. I usually suspect fouling of some sort. I'm going to suggest a group of things to try together. Any one of these may not be the solution but taken together may make a difference. (I'm ignoring the lock because you seem pretty sure you're getting a nice pan flash.)

First I'd go to a larger vent hole size. I usually recommend a #51 bit (.067). Someone suggested a .070" bit. I like either of these because it allows a pipe cleaner to be used. I don't trust a vent pick to clean fouling from a vent. (In lab settings I have seen a pick "grab" a bit of fouling on the way into the hole and deposit it back into the vent as the pick was removed.) A pipe cleaner doesn't do that.
Get priming powder next to the barrel. The flame going into the barrel is much hotter and ignition is from 15-25% quicker. This link will demonstrate this. Test

The order in which you do stuff may make a difference too. With a vent drilled to .067-.070 try this:

Wipe the barrel w damp patch
Use pipe cleaner (important to do this after wiping)
Load barrel
Run vent pick
Prime close to barrel

On any standard flint breech this should produce good ignition. Unusual breech systems can be a pain; I hope this isn't one of those.

Regards,
PLetch

 

[Jblk]

Even after drilling out my touch hole my GPR will not fire consistantly unless the pan is full of powder.

 

[sundog]

I drilled out the touch hole to 5/64, I use 3F for the main charge and the pan. I put a small feather shaft into the touch hole when loading and I only wipe every 3 or 4 shots.
I have no issues at all with ignition. It goes boom every time.

 

[Darkgael]

Valley Forge: I am at a loss as to a solution for you. I have three barrels for my GPR. They have their factory liners, untouched, and fire virtually every time.

Your loading procedure is almost exactly the same as mine. That's why I am at a loss - you should be having success but....you are not.
Wiping the bore after every shot with a damp patch and then a dry patch. Therein is the only difference in our procedures. I wipe with a patch that has been dampened with denatured alcohol (not rubbing alcohol). I do not run a dry patch down after it. Just the alcohol patch, down and up and then reload.
You did not say what you used to dampen the patch, maybe you do the same as I (I have trouble believing that such a minor difference, if there is one, could be the source of your FTFs but you seem to have tried everything else.)
Pete

 

[napolean]

Valley Forge, AND Duck creek,
Please hang in there, You've had some good pointers from the forum, Try to ward off any frustration.
As suggested, your problems may not be any ONE thing, and may not be the same problems for both of you.
Some things just to try:
Swab the bore AFTER seating the load, frizzen open, cock down. Should not load hard w/ 1 shot fouling.
Although not generally recomended, After a shot, blow down the muzzle while watching the vent, and listening to the air coming out. Should be a steady stream of air, if not or there is any sputtering, then something is indeed getting down in the breech.
Pour the powder slowly from your measure into the bore. you might even try pouring just part of the charge, do the patting on breech, and even a few upward pats on the butt plate (never "bounce" the butt on ground) and then add the remainder of the charge.
Try swabbing with a patch worm rather than a jag.
I know some of these sound like a PITA, but it may help isolate the problems.
Jon D

 

[Skylinewatcher]

My GPR is a heavy iron. I wonder if you are not tiring some and starting to tilt the gun. May have to get a bud to watch you around that 4th or 5th shot.

 

[paulvallandigham]

Like Zonie, I suspect its your loading and cleaning technique that is the problem- not the gun. PATIENCE is a virtue, as well as good timing!

The problem for new shooters is that they really don't know what " Damp" means, and its next to impossible to explain in words. I "Dampen" my cleaning patch by Wiping it over my tongue- No big goober of spit-- just the moisture that comes off of my tongue.{ think of only using enough "spit" to clean a 3 inch barrel. The rest of the moisture will already be in the bore from condensation.] That can obviously vary from day to day, depends on when you last drank, or ate anything, how much exercising you did before you shoot, how hot or cold it is, etc. With some spit on it, from my tongue, I fold the patch over on itself between my thumb and forefinger, and rub the spit into the fibers. I put the damp side DOWN on the muzzle to push into the barrel.

When I clean, AFTER EVERY SHOT, I run that dampened patch SLOWLY, as I want the moisture in the patch to wet the residue enough to let it soak off the steel bore, and into the fibers of my flannel patch.

I used a MARKED RAMROD( usually my Range rod for cleaning at the range) that lets me Know when I am Approaching the bottom( back) of the barrel. I stop the patch 1 inch up from the face of the breech plug- or in your case, above that powder chamber-- And pull it out. It comes out NASTY Looking- All Black, and WET( SLICK and SHINY).

Do you really want to shove any of that stuff into that powder chamber??

I didn't think so. But, you will be surprised at how many shooters never even look at their patches!

I lightly dampen another patch, and run this one down slowly, but now I am "Feeling" the patch run over the lands, to see if there are any spots where there is still CRUD stuck to the barrel. The new damp patch stops at Any such place, Again, to soak that spot and get that crud out into my patch. The Second damp patch is Gently run down to the back of the barrel, and allowed to sit there for a few seconds( count 5) to soak up any residue that is back there.

A. If you Slam that Damp patch into the back of the barrel fast, you will propel moisture( water, spit, alcohol, etc.) from the patch into that powder chamber, and squeeze moisture out of the patch, defeating its purpose.

B. If the patch is TOO Damp- remember that in addition to the spit with which you moisten the patch, there will normally be CONDENSATION moisture in the bore that also dampens the patch-- You will put water into that powder chamber, and down through that tiny hole into the flash channel.

Cleaning is for the sole purpose of removing residue and MOISTURE- usually condensation-- from the bore before loading the next powder charge. KEEP that GOAL in mine.

Now, assuming that as you remove this second dampened patch, the Bore FEELS clean, you now use DRY PATCHES. Run a dry patch all the way down the barrel, but SLOWLY So that you can feel for crud. When you get to the bottom of the barrel, let That Patch sit for a few seconds, so it can soak up any moisture and crud that might be in the corners where the breech plug meets the barrel. Now, as you pull that first dry patch, if you want to do so, you can scrub the bore back and forth with that patch in stages as it comes back out the barrel.

READ THE PATCH.

You want to find a patch that comes out light Gray- NO black. If you see any black, use another patch. If the drying patch feels almost as damp as your first dampened patch before you put that one down the barrel, USE ANOTHER dry patch.

READ THIS PATCH, TOO.

Until you develop a feel for how much or how little moisture is needed to clean your barrel, Use that .30 caliber bore brush to push a separate cleaning patch into that powder chamber to get the crud( and moisture) out of it.

I do believe that you can improve these guns my widening the flash channel- the small channel that comes from the middle of the bottom of that "powder chamber" over to the side of the barrel to the Vent Liner, or Touch Hole. You have to remove the Liner to gain access, but if you drill that hole even one numbered drill bit size larger, it will make a big difference in how easily your powder will flow through that flash channel and get over near the TH.

With these guns, use a SHORT vent pick, only to make sure that no moisture has clogged the opening with dampened powder. A small wire- like those sold to clear nipples, is more than adequate. And, do take Zonie's suggestion and open that Vent up to at least 1/16". You want dry powder right next to the opening to make sure you have fast ignition.

I have never heard, nor read, any complaints about the accuracy of these GPR barrels.

The problems, when they do exist, come in how well the Quality Control is working when those breechplugs are made. Sometimes, you get casting dross, or burrs left on the edges of those small holes.[Use a small wire down that flash channel to FEEL for dross, burrs, etc.] By enlarging that flash channel one drill bit size, you remove any of those burrs, or dross, and polish that channel smoother, so it doesn't HOLD crud as it did from the factory.

Because of the small size flash channel, you are limited in using only 3Fg powder in that flintlock. When that channel is enlarged, and the small hole at the bottom of the powder chamber is opened up, you can use 2Fg powder. But, that requires the work of a skilled machinist, or gunsmith.

Final observation after re-reading your post: DON'T pack down the powder any tighter than gravity will compact it in the bore, when you pour the powder down the barrel with the barrel held in a vertical position. You distort the shape of the ball doing so- and can't possibly do this the same with each shot-- ruining accuracy. With the smaller sized 3Fg powder, packing makes it much harder to fire IN A FLINTLOCK.

Remember, In a Percussion gun, that percussion cap has enough FIRE and power to go through that flash channel, thru that powder chamber, and still inject flame into the rest of the powder charge in the barrel. [ Don't believe it?? Take a percussion rifle- I don't care how long the barrel is--- out at night, in the dark, and fire off a cap, while watching that muzzle. You will see a long flame come out of that muzzle, every time. The darker it is, and the more adjusted your pupils are to see in the dark, the more vivid and long that flame will be seen to you.]

LOAD TO YOUR MARK on your ramrod and No more. No bouncing of your ramrod to see how high you can get it to fly, etc. Take that PRB down to the mark using only your fingertips. The Mark should be placed on that Ramrod when you feel the PRB grinding on the powder granules.

If, on future shots, you are having troubles getting that PRB down to your mark, it means that you have not cleaned the barrel properly. Along with that build up of fouling( crud, residue) you are also going to be leaving moisture back there, to foul this powder charge( crud acts like a sponge: What it taketh, it giveth back!)

Relative humidity plays a very important part in how a gun has to be cleaned between shots, or at all. You will find a lot of honestly different cleaning methods discussed here, because the members come from all over the country, and shoot all over.

That is why I am a Nag about "read your patches". Its the only way to know when there is a change in humidity- even during the same day, as so often happens here in Central Illinois on summer days. I am constantly checking wind direction here, because any change in wind direction means a change in the relative humidity, here. That is Not always the case in other parts of the country.

So, learn to read your patches, and adjust your cleaning practice to achieve that "gray " patch before pouring down the next load of powder. You should then be fine.

There is Nothing wrong with Chuck Dixon's directions. Its how you use them. Only you can apply the patience, and the observation of those patches to make an adjustment when needed. :thumbsup: :thumbsup:

 

[Rusty Spur 82]

Allow me to thank you sir,that was very dedicated on your part to supply all that information.You also may have solved my flint lock problem of my GPR.All that you have stated is definitely worth a shot.I am not the original poster but I did absorb much from you,Zonie and others.Just wanted to let you know that it is appreciated.

 

[ebiggs1]

I have three GPR’s and on the third one I didn't even give it a chance because I knew what had to be done to make them reliable shooters.
My suggestions are:
Replace the touch hole immediately with one that is drilled with a #51 or #50 drill.
Preferably coned on both sides.
Use 4f prime and don't be skimpy with it. It's cheap! Flat level in the pan. Don't bank it either way.
Don't swab the bore between shots. It is not necessary if you are using something like Bore Butter (or plain olive oil) for a patch lube.
You don't need to slap your gun either.
Learn to shoot the gun before you start other methods of this and that and accuracy tests come later, too.
You are using real black powder (use 3f)? You are using real flints? You might get a bore light and check that some machining slag isn't left behind in the breech area.
My GPR’s never ms-fire now and they are accurate rifles.
Plus there are other mods that need to be done to really make it a top rifle but that is later.

 

[hexblade]

Since Pedersoli frontier flinter has a small patent breech also, would all the advice about GPR apply to frontier (ie: drill vent to 4/64 or 5/64, use 3f instead of 2f)

Cheers

 

[ebiggs1]

I have no experience with the Pedersoli Frontier but I do have two other models from Pedersoli.
I did this to mine because the supplied touch hole is miserable and nearly worthless.

(Stock Pedersoli is on the left.)
2nd photo is inside of liner.

 

[Skylinewatcher]

I bought my GPR second hand. It's bore looks as big as yours and as far as I know nobody drilled it. I know I didn't. I wonder if they are making them different now. :hmm:

 

[ebiggs1]

I am sorry. The photos are of a Pedersoli not a Lyman. The previous poster asked about his Pedersoli and this is a Lyman thread. At any rate your touch hole should resemble them. In my humble opinio that is!

 

[ebiggs1]

I bought my GPR second hand. It's bore looks as big as yours and as far as I know nobody drilled it. I know I didn't. I wonder if they are making them different now. :hmm:

Lyman touch hole liners.

 

[dckcrk]

Mine didn't look anything like the photo above. The outside face was absolutely flat except for the slot and the touch hole was tiny. Less than .050. There is a cone on the inside face.

 

[nkbj]

After a GPR goes bang the first time then it will probably be the cleaning technique that is the problem. Try this just for an experiment after the first shot.
Load powder.
Seat a folded up dry patch on top of the powder charge.
Damp and dry patch the barrel.
Load the patched ball.

If it still has ignition problems then you have eliminated the cleaning technique as the source of the problem.
That said, there is another problem associated with having the touch hole too small. The volume of gas and particulates outflow you have when the gun goes off helps to keep the ignition channel clear and let the next charge get positioned. Even more of a problem with that GPR geometry.