I snuck out this morning to try out the new LH Lyman .54 GPR flintlock. Even before I left I called the gun shop yesterday and told him to get me two RMC vent liners. I knew I was going to need them.
The weather was about 70* and about 90% humidity.
All shots were made using a Hornady .530" ball and .018" pillow tick patch. Swabbing between each shot with T-17 patch/dry patch.
I shot the first target using 80 gr of FFg at 25 yds. As you can see the very first shot just caught the bottom of the paper. After a sight adjustment shot #2 about 1 1/2" below the bottom of the bull.
Then after another sight adjustment I shot #3, 4 and 5 and they grouped really nice. I thought I had this rifle figured out already.
Target #2: I shot the same 80 gr load at 50 yds. As you can see, 2 shots hit paper. Don't know where #3 is?
Target #3: I bumped up the charge to 90 gr and shot a 'decent' group with a new rifle. But I have to admit, the stock vent liner along with the humidity was giving me fits.
Target #4: This time I went up to 100 gr. The first 2 shots were touching. Then I had a long delayed hang fire which I discounted. I loaded up the third shot and shot just above the other 2.
All in all it was a decent shoot. Rushing to try and beat what looked like impending rain.
It does appear though that this rifle is going to be a powder hog.
I have the rear sight raised up as high as I dare without losing the screw/spring. Looks like I will be filing the front sight down about 1/16" - 3/32".

Awesome!!!

You will really like the RMC vent liners as ccomparded to the stock liners. I am to the point that I even believe the allen wrench insert in the vent liner helpd focus the pan han and sparks through the vent liner.

I think Dave has suggested the same thing about the need for powder when he is shooting his rifles...

That's darn good Bronko. Fun, aren't they? (And frustrating if you're getting a pan flash with no BOOM.) The RMC liner will fix that. While you waiting, drill out the stock liner a little.

I wouldn't file the sight until you get a few dozen more shots out of it. Or even better, get the Lyman 57 peep and live happily ever after. You will know true joy when you take your first deer with that .54 flinter.

No guarantee it will fix it. It didn't on mine. I'd still get slow ignition now and then. Even when I did everything exactly the same.

I guess the stars weren't lined up just right.

or BEAR!!!!!

I know all about the RMC liners. I've been using them for years in my other flinters. As soon as I saw the liner in this I was going to change it when I got home. But it must have went with the other .50 cal GPH I had.
I've taken several deer with a .50 flinter and one with a .45 flinter but none with a .54 yet. I hope that changes come this season. As for bear - I have a .54 GM 1:70 caplock for those guys. Along with a .54 Lyman Plains pistol as back up.
I may just get the #57 sight. But I wonder how it will work with the LH lock now that I think about it?

My two Lyman Flintlocks are powder pigs also. The Trade Rifle for some reason wants 90 grains of 2f and NOT 3f. When I tried 3f it sprayed all over the place. My Great Plains Hunter shoots sabots and I usually shoot 90 grains with them depending on the weight of the projectile.

For a first day on the range.. that is darn good shooting. Also try moving your pan powder around. My Trade Rifle likes it on the outside edge of the pan the the Great Plains likes it up near the touch hole. My T/C Flinter wants just a little powder on the outside edge. Its all learned with time. I would shoot that a little more before I start to file. But since you're at the top of the ramp already a little filing might not hurt.

That RMC vent liner is the only one I will use.

That is very good shooting, especially for a new rifle.

What sort of accuracy are you getting from the GPH? What bullets did it shoot the best? Leaving out heavy lead conical, because they have too much recoil for me.

Dave I never thought of moving the pan powder to the outside of the pan. I had it in the bottom but it would just flash and no boom. I had to fill the pan and tap the opposite side of the stock to get the powder right up against the touch hole. That is the only way the rifle would fire. I had 4 flash in the pans before the first ball even went downrange.
I ordered the Lyman 57 sight. I was going to get the #17 globe front too but I am going to wait an see how it is with just the #57GPR sight. I got it from Optics Planet. Good price - free shipping for any orders over $29. I just hope the sight doesn't get in the way of the hammer.