Ignition issue with Flint GPR

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Went shooting with a new-to-me group yesterday and all generally went well and was enjoyable, until it wasn’t. I have only the last year or so got serious about BP shooting. I have played with BP guns on and off for decades but really only got serious lately. To that end I decided to seek out a BP club to shoot with and yesterday was my first outing with them.

Anyway, my pistol as fine and the first five shots out of my Flint GPR were also fine. I noticed other shooters cleaning (swabbing) between every shot and felt maybe I ought to swab mine. So between the fifth and sixth shot I ran a spit patch own and out, turned it around and down and out and loaded up. Pulled the trigger, big flash, no bang. I reprimed a couple of times and still nothing. Finally the ligh bulb went on and I picked the flash hole and reprimed and got bang. Loaded up another round and nothing. No amount to repriming or picking got ignition.

Got disgusted, made some comment about sticking with caplocks from now on, and bagged the GPR and took it to the car. I pulled the bullet and cleaned the GPR up today and pondered things. I think I must have pushed a bunch of crap down in the barrel blocking the flash hole when I swabbed the bore is all I can figure. I should have known better than try and clean a gun, I don’t usually clean my (unmentionable) guns until they don’t work or are so nasty I am embarrassed.

So, I suppose the moral is not to clean as long as the gun is loading fine?
 
I'd say, it depends. You really have to shoot the rifle to get to know how it likes things; some are OK not swabbing and others like to be cleaned after each shot. For me I've found that I can get 10 or so shots before my 50 cal Southern Mountain Rifle needs a cleaning. One thing is to be sure to get any moisture out of the bore before you try load again. Keep at it and you'll figure it out.
 
I had a similar issue with a T/C flintlock, 3 to 5 shots is all I could get before it stopped shooting. Picking usually helped, but sometimes it didn't help and the ball had to be pulled. Swapped out the vent liner with a Track of the Wolf stainless vent liner and the problems went away. Just to test it, I loaded without swabbing between shots and I could get 15 to 18 shots without a misfire.

Muzzleloaders require more attention than the unmentionables. I clean mine with alcohol before I leave the house to help remove the oils from storage and hopefully prevent any gunk being pushed down to the breech plug / vent liner. I clean throughly after shooting, dry the bore and oil well for storage.
 
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With my flint GPR, I do not have to swab between shots. .54 cal, butter bore lube, 80 grains. I can go about twenty shots before thinking about swabbing.
That said, religeiosly between shots I wipe the pan and frizzen clean (just a quick wipe to get residue) and after loading clear the vent. That is very critical for consistent ignition. Of course, monitor your flint. A good new flint I can usually go six, sometimes a dozen shots before touching up, but if it starts to lose its sharp edge I just give it a few taps with my screwdriver to freshen it up. I did open up the flashhole a bit early on...probably more than I needed to. Do a search for recommendations on that.
 
Yes, I bought it new last year and have only had it out a couple of times. I don’t recall any issues the first time but this time gave me trouble. Maybe a larger/different flash hole might help?
I recommend either drilling the Lyman vent liner with a 1/16" drill bit, or put in an RMC liner. I think I had to drill the RMC out to 1/16" also (foggy brain syndrome). I recommend the RMC vent liner.
 
I have found that when swabbing between shots, or after a string of shots, that the use of a smaller jag than the bore diameter, i.e. .45 jag in a .50 caliber, and a alcohol soaked patch do the job without pushing gunk into the breech area. The smaller jag and patch ride down the bore, then bunch up on the return stroke to pull out the fouling. The alcohol evaporates quickly so as not to contaminate the next powder charge.
 
Your issue was more a disfunction of the patent breech than the touch hole liner. When you swabbed the bore, you pushed fouling into that smaller bore and prevented enough fresh powder to reach the flash channel. IMO, you were better to continue shooting the rifle without swabbing provided it still loaded easily.

The suggestion of using a smaller diameter jag for swabbing is a good one. The undersize jag and patched is pushed down over the fouling, and the patch bunches up and pulls fouling OUT. With a tight jag and patch you're pushing fouling down and clogging the antechamber.
 
Another vote for the RMC vent liner. I also keep a small caliber brush in my box that I can wrap a patch around to clean out that patent breach if I need to. But I have not had any issues shooting 15 to 20 shots. I also use Mr Flintlocks patch lube
 
@excess650 is correct. When the pan powder is ignited and the main charge fails to go off, the problem is a blockage in the flash channel. The blockage is either the chambered breech is clogged with fouling or the touch hole is blocked. All too often, we wipe with a patch that is too wet so not only is fouling pushed into the breech area but the breech is wet enough to prevent firing. When you fire the rifle, look into the pan. If its wet, assume the breech is wet too. This is the time to run a thin brush through the touch hole to open it up. When you wipe the bore between shots, you are not cleaning the rifle but removing some of the fouling from the grooves to have a consistent bore condition. @BigAl52 is also offering a good procedure of using a small caliber brush and dry patch to clean that chambered breech.
 
Also I will add the "proper" swabbing method. Already mentioned above, your jag should not be bore tight. The reason is that the patch should not shove everything down the bore but instead, pull everything out. The damp patch should be damp, not at all soaked. Push the patched jag slowly down to the breach and let it set 5-10 seconds (do not pump it up and down). That allows a little time for the fouling to soften. Now Pull the patch out. Flip it over and repeat. Follow that by a dry patch, both sides.
The 2 main culprets involved with posts like this are usually 1) Too wet a patch and 2) Pumping action while swabbing.
 
Got disgusted, made some comment about sticking with caplocks from now on, and bagged the GPR and took it to the car. I pulled the bullet and cleaned the GPR up today and pondered things. I think I must have pushed a bunch of crap down in the barrel blocking the flash hole when I swabbed the bore is all I can figure. I should have known better than try and clean a gun, I don’t usually clean my (unmentionable) guns until they don’t work or are so nasty I am embarrassed.

So, I suppose the moral is not to clean as long as the gun is loading fine?
Admitting that you don't properly maintain your gear is the first hint. Keep your guns clean - ALL OF THEM.
Read and learn the proper way to swab (mentioned above several times). Read and learn how to clean after a shooting trip. (MANDATORY)
The barrel on the GPR will dismount with ease - drop the breech end in a bucket of warm water with a bit of dish soap and pump it with a patch and ramrod. GET IT CLEAN!
Think about how your own tailpipe would get if you didn't clean it after each use.
Go ahead and neglect cleaning your black powder gun and leaving it dirty "forever" after shooting it.
You won't need to come here and brag about neglecting your gun - because it will be so rusted and corroded that it will never be worth trying to shoot again.
I have the GPR in both percussion and flint - and have no issues with either - your "disgust" is misplaced - it is not the gun - it is the user that makes them run right.
 
On my T/C I shoot a 490 round ball with a .015 patch and Mink oil, 70 gr. of 3f powder. I can go 25-30 shots before thinking about barrel swabbing. I have a rmc touch hole liner. For consistent shots I need to pick the vent every shot and clean frizzen, flint, and flash pan with alcohol, then wipe with clean rag. I carry a small spray bottle of alcohol in my pocket along with a small wipe cloth.
 
On my T/C I shoot a 490 round ball with a .015 patch and Mink oil, 70 gr. of 3f powder. I can go 25-30 shots before thinking about barrel swabbing. I have a rmc touch hole liner. For consistent shots I need to pick the vent every shot and clean frizzen, flint, and flash pan with alcohol, then wipe with clean rag. I carry a small spray bottle of alcohol in my pocket along with a small wipe cloth.
I follow the same routine - except I use WINDEX - it smells like a clean house instead of a Dr.'s office......
 
I bought my first flintlock over 25 years ago, a GPR, and from what I'm reading things sure have changed. At the time I was a fairly capable caplock shooter with some accomplishments at the firing line. So I wasn't anticipating any problems, I was sure wrong about that. The rifle only actually shot a ball down the barrel after numerous attempts. To say I was questioning the whole idea of owning flintlocks would be an understatement.
But I was a Tool & Die maker with a large shop at my disposal so I began to look into the problem. The main problem was the touch hole liner. There was a deep screwdriver slot with a tiny hole at the bottom and that hole went deep into the liner before contacting a small counterbored hole. It would take a Houdini for the pan fire to find the powder in the barrel. So I made some changes. I drilled out the TH, made the counterbored hole as large as possible and bored it deeper to bring the powder to the fire. Then took a ball endmill and opened up the screw slot.
Well that took care of most of my problems right there. Suddenly my rifle was firing almost all the time and it was a lot faster also. Not being in the flintlock family it took awhile to discover the RMC TH liner was basically identical to the ones I was making. I ordered a few and they worked so well that's all I used in that rifle until I sold it. Now I build my own rifles and only use Chambers white lightning liners.
Another problem is that patent breech which is smaller than the bore diameter. All to often when pouring my main charge down the barrel the powder would bridge when it encountered the smaller hole and no powder would be in the Patent breech. I learned to hold my rifle at an angle and pour slower when charging the rifle. Sometimes tapping the barrel with a palm.
And the original problem of swabbing and blocking the hole with fouling. Well, back in the old days when I shot at a lot matches with old timers and flintlocks, that was called a "Klinker", and regardless of the spelling a hole had to be opened up to the powder to expect ignition.
The best way to tackle "Klinkers" is not to get one in the first place.
These problems seem to go away after you learn your rifle. A process involving many, many shots. Be patient and it will come.
 
A lot of good advice here. I will add that when I clean the barrel with a bucket of warm water and just a small squeeze of dish soap, I make a point with TC and Lyman rifles to use a 32-35 caliber bronze bore brush to scrub out the patent breech. An adapter goes between the 8-32 threaded brush and the 10-32 threaded rod. As noted by others, a good deal of crap can build up in there, even with careful swabbing technique.

On many factory built rifles the opening in the vent is too small. I put together a group of three drill bits, #s 55 (.0520), 54 (.055), and 53 (.0595), and 1/16 (.0625). Vents are enlarged one step at a time until ignition is consistent.
 
Lyman uses a chambered breech plug, this is bad for reliability, not much the average guy can do about that. Drill out your liner with a 1/16" drill bit. Adjust the size of your jag with a triangular file so that a patch slides down easy. Yet, bunches up tighter on the way out. Once you have that figured out stick to the same cleaning patches. I buy the large bundles of canton flannel GI type patches and make all the jags for all of my rifles work for that one patch.

As for gunk in the chambered breech plug, a nylon brush may help. A bronze brush can get very stuck if you are unlucky. I do not recall what size of brush fits the chamber, maybe someone does? A pointy dowel might be useful to see where the chambers marked the pointy end. The internal diameter could be roughly determined that way.

I have unbreeched two of these rifles and opened up the chamber. I don't remember if I sized them for a 30 cal or 357 brush. You don't want to go too large and weaken the plug.
 
The suggestions to use an undersized jag for swabbing are right on...I learned this the same way you did (misfires after swabbing), and I wish that Lyman would put that info in their manual (if it is there it is buried somewhere).

Even when swabbing with an undersized jag, I was still getting occasional misfires with my GPR until I drilled out the touchhole liner to 1/16 as many suggested to me. Now it goes off every time.

As a side note, my GPR would get extremely difficult to load after about 3 shots (thus requiring swabbing, and creating the misfire issue). I polished the bore with scotch-brite patches and now I can go 10-20 shots before loading gets difficult. I still swab about every 5 shots just for a little more consistency. Duelist1954 has a YouTube video on the same problem with a GPR.
 
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