Faster Ignition With A GPR?

[TarletonRanger]

Howdy folks, I know a lot of members here shoot and enjoy the Lyman GPR's, and I myself picked one up about two years ago for my first flinter. Having been an avid caplock shooter and hunter for years, I thought it would be a fun step to take up hunting with a flintlock.

I am however, still having a few issues with my rifle, which is actually the flintlock version of the GPH.

1) Ignition time is deffinately slower than desired. I've been priming with a half pan of 3FG using black english flints and I consistently get a "CLACK"....BOOM!! Less than a second of delay, but it is VERY noticeable. That is when I don't just get the flash in the pan.

I'm thinking of trying to pickup some 4FG to use as priming as well as locating a new vent liner...preferably one that is coned. Do yall have any preferences on this end?

2) I've had a heck of a time with the sights on this model. My current load is 70gr of FFG with a 385gr Buffalo Bullet loaded on top. The adjustable rear sight is raised all the way up and the front site has been filed considerably down. This puts me about an inch low at 50 yards. If I move the poder charge up to 90gr, it will shoot about 6-8 inches low. GRRR!!

So, first and foremost on my list of improvements is getting a much faster ignition time. I believe I have enough front site left that I could take off enough to bring the 70gr loading up that extra inch.

What do ya'll think?

Jake

 

[ndbilly]

I don't know what the conventional thinking is on powder size vs caliber but if you have a .50 caliber GPR you can use 3F in the tube and 4F in the pan and you will definately get faster ignition times. If you have a .54 caliber, you will still get a faster ignition with 4F in the pan even with 2F in the tube. Don't know if the pros condone 3F in that size bore. I've only ever used 2F. Also, tilt the rifle to the side just a bit when priming and trickle some powder directly into the touch hole. Less is better when it comes to priming the pan. The more powder you have in there, the longer the ignition time.

Sorry I can't offer any suggestions regarding the sights.

 

[J.D.]

Ignition time is deffinately slower than desired. I've been priming with a half pan of 3FG using black english flints and I consistently get a "CLACK"....BOOM!! Less than a second of delay, but it is VERY noticeable. That is when I don't just get the flash in the pan.

I'm thinking of trying to pickup some 4FG to use as priming as well as locating a new vent liner...preferably one that is coned. Do yall have any preferences on this end?
Jake

There may, or may not be a noticable difference in ingintion speed when priming with 4F as opposed to 3F. I would drill out the touch hole to a slightly larger diameter. That touchhole is probably .062 dia.

A number 51 drill bit = .o67 dia
# 50 =.070
# 49 =.073
# 48 =.076

I suggest drilling the TH to .070 and see if that improves ignition. Then try .073.

I prefer to stop at .073 or .076. Anything larger begins to reduce pressures.

I would also cone the outside of the TH with a 1/4-5/16 dia, or so, drill bit. IMHO, the screw slot in the liner can be major contributor to slow igniton, so cone the outside of the liner, just enough that the bottom of the cone is the same depth of the screw slot.

IMHO,the idea that anything more than just enough powder to cover the bottom of the pan is too much, is hogwash. Try just covering the bottom of the pan and increase the amount of prime until the powder reaches just below the bottom of the TH.

Use the amount of prime that gives the best ignition. I prefer to fill the pan about half full.

Larry Plecher did a slow motion study of a number of flintlocks and found that the prime is ignited above the pan as it is thrown into the air by the action of the lock, so I have my doubts that a pan can be overfilled.

J.D.

 

[cowpoke1955]

I took my stock vent liner and drilled the touch hole to 5/64th inch. This will allow more fire through the touch hole. Take a 1/4 inch drill bit and drill the outside of the liner, forming a cone. Leave enough on the outside diameter containing the screw driver slot. This will focus the flash to the tough hole. Measure the breech plug wall thickness where the liner screws into and trim the liner to that depth. This will allow more powder the get closer to the flash. Be sure to use a vent pick to insure the touch hole is clear. Use FFFFg for prime if you can find it. After all this my .54 GPR flinter is as reliable as any percussion and almost as fast. Try using FFFg for your main charge. It burns a little faster and will give you a different point of impact. Just might do the trick. A friend of mine uses FFFg in his .54 and shoots real nice groups. FFg gives him a shotgun pattern. Can't say this will fix your problem, but it worked for me.

 

[Dobson]

I also go with all the above. I opened up the touch hole to 2mm (metric) and it works a treat. I also coned out the outside as recommended and removed the liner then gound down the length a bit (as much as i dared, afterall you have to have some threads holding it in) then screwed it in as far as it would go without protruding into the chamber. If you load her properly she will be fast and reliable. Just like the wife! Ooops did that just slip out! Sorry.
Regs Dobson

 

[papellet]

I use 3F in the pan and fine no difference than when using 4F, obviously results vary.
I changed my vent liner out to one offered by[url] Rmcsports.com[/url]. It is coned on both sides, the outside is coned so an allen wrench is used vice a slotted screwdriver. This change made the most significant difference in the delay time, vertually eliminating it. I also used Flitz to polish the pan.

 

[roundball]

I changed my vent liner out to one offered by[url] Rmcsports.com[/url]. It is coned on both sides, the outside is coned so an allen wrench is used vice a slotted screwdriver. This change made the most significant difference in the delay time, vertually eliminating it.

That's the redesigned vent liner TC cut into their barrel production 7-8 years ago...with TC's redesigned lock assembly, redesigned liner, 4F in the pan, and 3F in the bore ignition on my TC Flintlocks simply seems instantaneous...a single event...got them all upgraded with redesigned locks & liners...makes shooting on the weekends a real pleasure
:thumbsup:

 

[horsesoldier03]

I would fix the delayed ignition first. My thinking is that you may not reckognize it, but when you have the delayed ignition, you anticpate recoil and lean into it which causes you to move your point of aim low. Also, Front sights arnt expensive, might want to get a new one.

 

[TarletonRanger]

I may very well try that vent liner by RMC! I know I haven't been keepin the vent pick in the VH during loading, so that's deffinately something I'll be tryin next as well. Also, another member mentioned wrapping my flints in lead instead of leather in the jaws of the lock. Have any of yall tried this? It seems that a new vent liner, possibly lead wrapped flints, and using the touch hole pick during loading may be the ticket.

I'm interested, for those of you who do wrap your flints in lead....what do you use to make the wrap? I would think that a flattened musket ball might be a bit too thick. :wink:

Jake

 

[Old Charlie]

My GPR was a might slow . I drilled the vent out to 1/16 and that took care of it.
Old Charlie

 

[Gungeek]

My 54 GPR is pretty fast with 4F flash powder...and no mods done. :grin:
[url] http://www.youtube.com/watch?v=hLyOAD-RoD4[/url]


scotty,

 

[OLD CROW]

I USE .040inch thick lead x5/8 inch wide ,length depends on size of flint.(GOOD ENGLISH from PALOUSE TRADING in MOSCOW IDAHO). touchhole poened to .070 with fffg in pan and main charge. 50-60 gr. target/range loads and 70/90 hunting. no miss fires with this set up (.50 cal. kentucky rifle. donated the last can of 4F as a BLANKET Prize at last B.P.Shoot. seems it peppered my forehead . not so with 3f in the pan. got lead from marine supply shop for insulation OLD CROW