Lapping & loads for Green Mountain Flintlock

[Sam Ramirez]

I recently purchased a used TC Flintlock in 50 cal. It came with a Green Mountain replacement barrel. The barrel is 32 inches long and my research tells me it has a 1:70 twist. I suspect the previous owner (I purchased it used from a gun shop so I don't know the previous owner) was using it with round balls in match shooting.

My first question is this: Do I need to do the lapping procedure for a Green Mountain barrel? The rifling for Green Mountain barrels is done with a laser. I do plan on contacting the gun dealer to try and contact the previous owner. He may have already lapped the barrel.

I have only fired the rifle with 370 grain Maxi-Balls and 90 grains of Goex fffg in preparation for the late Muzzleloader season in Pennsylvania. It kicks pretty hard, but I get 2 inch groups at 50 yards.

My second question is this: Does any one have experience with this barrel/caliber using round balls? What I need is advice on what load to use for match shooting. I already have the 490 balls and 015 patches. I want to get ready for the monthly ML matches at my local sportman's club. I only joined recently and I would like to do good! My only concern is for accuracy on paper targets at 50 yards.

I look forward to whatever wisdom you all might have to share.

As for wisdom, I have a tale I should share with all of you! When I found this rifle on the gun shop rack I fell in love with it. It had the special barrel and lots of fancy brass inlays! It was in great shape and the price was VERY right! I was prepared to buy it and all the accessories, ammo, etc. I was even going to buy an old eastern European 9mm pistol for my 25 year old son. The shop owner wrote it all up and guess what! He didn't accept credit or debit cards! I couldn't believe it. It was a very nice shop. A quarter million in merchandise? Lots of high end merchandise. My bill was over $800. I had less than $300 in cash and I haven't carried a check book in years. I left that shop a little embarrassed and very disappointed. We went to several more gun shops that night (it was 2 days before Christmas). I did not find another muzzleloader that I could get excited about but I did find and purchase a nice 9mm Beretta for my son. At any rate, I called the first store and he agreed to set the rifle aside for me (we were 50 miles away).

The next morning (Christmas Eve) we went straight to the bank, withdrew some cash and headed for the gunshop. A few hours later we were at the gun club (which I only recently joined) and ready to play with our new toys. My son and his friend emptied a couple clips of 9mm rugers and 2 other younger men were firing their pistols. A couple of other people were just standing around. I announced (loudly) that I was about to fire my flintlock, but that it was NOT LOADED. I was only testing the flashpan and flint! So I layed it across the the bench, aimed down range (sorta) and pulled the trigger. KABOOM! Now that was a shocker for everyone. Boy did I feel stupid!

The rifle had been sitting on the store rack loaded and for how long is anyone's guess. God knows how many customers picked it up and pointed it around the store. And we drove around with a car load of people and a loaded rifle (I know that a ML is considered to be unloaded when the flash pan is clear).

This story is about safety. Habits are good when it comes to safety. I consider all weapons to be loaded. Always. When I filled the flash pan and pointed down range I was doing it out of habit. To make sure it wasn't loaded. This rifle had really been gussied up by the previous owner. He had burned a spiral up the length of the ramrod and there was no mark to indicate depth. So I did what I would have done under any circumstances. Just to be sure. I know I could have blown down the muzzle, but I really didn't think it was loaded! That belief didn't keep me from sticking to my safety habit. I even had my glasses and ear plugs in.

When it comes to safety, we can never be too diligent.

[PA_RIDGE_RUNNER]

First of all I am from central PA also. I own two muzzleloaders with green mountain barrels and have not lapped either one and they shoot fine. My inline, a Knight Bighorn, will hold a one inch group at 100 yds. My RMC accusporter will do the same at 50 with open sights.

I am truly amazed that with a 1:70 twist that you got any sort of group with a maxi ball. That barrel is designed to shoot the patched round ball only. With that twist you can push a round ball pretty hard and still be accurate but I have never heard anyone getting that kind of accuracy with a maxiball in a barrel with that twist.

I can't help you with loads for your barrel. Green Mountain may be able to help you with loads though.

You are most fortunate with the rifle being loaded when you bought it. To check a muzzleloader especially a flintlock you slide the ramrod down the barrel and put your thumbnail on the rod and keep it there while you remove the rod. Lay the rod along the barrel and see where the tip come in relation to the seam where the breech plug and barrel meet. It should come very close to that spot if not it is either loaded or has an obstruction.

[Sam Ramirez]

Thanks

for yet another way to check for obstructions or a loaded gun. Like I said in the original post, if I thought there was ANY chance that it was loaded when I bought it, I would have blown in the barrel, at the very least. All's well that ends well.

As for the hunting loads, I know that my barrel isn't meant to shoot a maxi ball well. TC compromises (sorta) with the 48 spin to accommodate ball and maxi balls. Green Mountain uses a MUCH faster twist for their Long Range Hunter barrels (1:28). I was surprised with the results as well, but was able to repeat those groups several times at 50 yards. I found them to be very acceptable for hunting in PA and I wouldn't take a shot at much farther anyhow.

Thanks again,

Sam

[PA_RIDGE_RUNNER]

Another way to check a barrel for load is to stand the rifle upright and insert the ramrod then pull the rod up about 4 inches and drop it. If it is empty you will hear a very metal to metal ping and the ramrod should bounce. If you hear a dull thud and no or little bounce there is something in the barrel you can also remove the vent liner and shine a light down the barrel and be able to see some light inside the firing chamber. I have found this works best in very dim light.