Finding A Load - Lyman GPR

[PALongbow]

As many of you know I am new to flintlocks. I have been trying to find the load that shoots the best out of my Lyman GPR. With the barrel still being in the break in state I am mostly just trying to get use to the gun itself and trigger pull. I did however find a couple of combinations that seem to group very well for me at 25 yards. The load that seemed to group the best out of my rifle was....

Goex 2F 80-90 grain - Goex 4F prime
.018 pillow ticking lubed with Butter Bore
.530 Hornady ball

I did collect some patches that had four little perforations. It seemed to be from my more tighter patch/ball combination (.535 ball & .018 pillow ticking). This combination grouped pretty decent but was a bear to load. Any idea why I would see these perferations in the patch? Also should I be working on finding the right load out to 50 yards instead of 25 yards?

Ron

 

[boar]

Ron Sounds like lands are cuting the patch,some may be sharper than others. Log Cabin told me years ago it took 200 shots to break in barrel.Maybe some hornets nest on top of the powder to seal the gas til gets broke in. Some do the fire lapping. Valve grinding compound on the patch.Then shoot. I have not done this. I have used it on a gun with rough bore that was tearing patchs,I just used the ramrod.It help the gun. Dilly

 

[Swampman]

I'd try 60 grains of 3f Goex and a .520 ball.

 

[AZ-Robert]

I think Boar has it right, Ron - the lands are probably slicing the patch on that tight combo.

Check out what Bob Spencer has to say about picking a range. Short version of his advice, if you plan on using that gun to hunt, you want it "zeroed" at 100 yards, and you can sight it in at 12.5 yards to get there:
[url] http://home.insightbb.com/~bspen/trajectories.html[/url]
[url] http://home.insightbb.com/~bspen/sighting.html[/url]

 

[Zonie]

You can speed up the "break in" by buying some #00 steel wool.
Tear of a small piece and wrap it around your .54 caliber brass cleaning jag (button) and work it up and down the length of the bore.
Change the steel wool often to keep it cutting.

This will not wear out the bore but it will dull up the edges of the rifleing grooves so they won't cut your patches.
You might also want to check out the sharpness of the rifleing grooves at the muzzle.
Often these are left sharp and this too will cut your patch during loading.

For the muzzle, I prefer to use some 400 grit silicone carbide (black wet/dry) sandpaper.
Tearing off a small piece of the paper and pressing it into the muzzle a little way with my finger, I then use a rotary motion back and forth to get rid of those sharp edges.
Be sure to keep this sanding uniform around the bore.
If you don't like the polished bare metal look of the results, a little instant blueing will recolor it so that the barrel will look as good as new.

 

[PALongbow]

Did I put this post in the wrong forum? I saw it was moved this morning? Couldn't find where it was moved from and to...

Ron

 

[CoyoteJoe]

Down right confusticatin ain't it! :rotf: Got me too.

 

I was going to suggest that if he did'nt want to do it the old fashioned way and shoot a few hundred rounds through it, he could have his barrel lapped. But you having mentioned the #00 Steel Wool, well that sounds a whole lot easier. By the way, that's the first time I've ever heard of doing that. Guess it goes to show, you learn something new every day!

 

[410-er]

I used 0000# steel wool with an oil of some kind.Works great on light surface rust with oil with out hurting the blueing.Would be shooting at 50yds. to get better idea.Try any and all combinations till you find what it likes to eat.I would positivly stick with a .018 or .020 patch.My 54 GPR likes,
RB .530 or .535(either)
Goex FFg 100 grs.
.020 sq. cut pillow tick(1 1/2")
Stumpys Moose Milk
Wet patch and dry patch when you change a factor.Uniformity when shooting is the key.

 

[cayugad]

The way I smooth out my ruff barrels is with a chunk of Scotch Brite Scouring Pads and some J-B Bore Paste. I take and cut a chunk of the Scotch Brite and smear it with the Bore Paste and put that on a patch worm. If the Scotch Brite is a worn out one, you can even use a cleaning jag.

Work that through the bore for about 15 strokes, then add a little more of the bore paste and keep at it. I like to do 50 strokes and then clean the rifle and shoot it. You're not really lapping it here, you are just dulling the ruff spots.

Also you might want to try some different kinds of patches and see if it makes a difference. I use a pillow tick patch in my Trade Rifle and it works excellent with 90 grains of Goex.

 

[PALongbow]

At the end of the barrel I can feel some sharp spots on the edge of the rifling. I only have about 60 shots through this rifle so far so I do know that an additional break-in period is required. I sat down and examined the targets. The 90 grains of 2F Goex, .018 pillow ticking patches and .530 Hornady ball seemed to group the best at 25 yards (holes all touching). I will be shooting out to 50 yards on the next range session to see if it wasn't just luck.

Ron

 

[Tim Evers]

Ron,

That is the exact load that I found most accurate in my GPR. I tried using less powder as I just shoot for fun at 50 yard targets but the more 2F I used the better it shot. My bore needed a bit of a massage as well. I use pot scrubers that you find in grocery stores and are used to get after really dirty pans. They're flat copper looking balls of sharp ribbon. (my magnet sticks to them so they ain't red metal) I take 2 pair of pliars and jerk out a bunch of the strips and rap them around an old bore brush so it fits good and tight, and scrub the bore like the dickens. Be carful handling the stuff as it's sharp as heck.

This stuff was recomended by a gunsmith friend of mine and though I was scared at first to use the stuff at first, it sits handy on my gunsmithing bench and gets used all the time. Cleans leading out of a bore in a couple strokes as slick as a whistle.

 

[Ranch 13]

Most likely if you drop that charge to 55 grs and jump up to a .535 ball you'll see a drastic improvment in target accuracy.
Also when you load the gun place something on the order of a jay feather, or pipe cleaner in the touch hole , and only use about 1 gr or less of 4f in the pan, and as you mount the rifle to shoot tip it so the priming powder settles towards the outside of the pan you get more consistant ignition.

 

[strongarm]

My GPR percussion likes 90 grains of FF Goex and a .020 patch. The four holes can be from either too thin of a patch or your barrel needs lapping. After 4 years of shooting it never when away after break-in. Lymans are natorious for that. I bought a lapping kit from Midway called a Wheeler Engineering Kit (for $25)after reading an article on lapping in the August 2005 issue of Muzzle Blasts, the official publication of the National Muzzleloading Rifle Association.

The results were fantastic!