Finally Shot the Gemmer Hawken

Back in January I got a .54 caliber flint Investarm Gemmer Hawken. It's the current version of the Lyman Great Plains Rifle that was sold for almost 50 years here in the US. I bought this rifle for a couple reasons. First, I wanted something a bit shorter than my longrifle for hunting. Second, I wanted the power of a .54. The deer we hunt up in Tioga get big and I would really like a complete pass-through to maximize blood trails. The huge doe I shot in 2022 stopped the .50 caliber ball I shot and the blood trail was very hard to follow. Bigger holes and two of them mean more blood out and air in, so hopefully blood trails will be a lot shorter.

Anyway, life got in the way and I didn't not shoot he rifle until today.

This is my first five shots, fired off the bench, from 50 yards. My point of aim was 6:00 on the top bullseye. As expected, it shot low because these rifles come with an extra tall front sight.

The lowest shot was the first, with the rest clustered into a couple inches. This is about as good as I can shoot from the bench with open iron sights, even with a cartridge gun, much less a flintlock. I'm quite happy with the group.

The load consisted of:

• Hornady .530" round ball
• 0.018" ticking patches lubed with October Country's Bumbling Bear Grease
• 80 grains of Scheutzen 2Fg black powder

Ignition was perfect the whole day. As long as I got spark there were no flashes in the pan and ignition was quick. I had to reverse the agate flint that came with the gun after 5 shots, and it last another 5 after that. I then replaced it with a real flint.

To raise the point of impact I needed to shorten the front sight. The file I had with me was too fine to remove enough metal in a reasonable amount of time so after awhile I gave up on it. After I got home I took the barrel out to my shop where I had a coarser file and took some off the top of the front sight.

If you know the sight radius of your gun, the distance to the target, and how much you need to move the point of impact, you can use this formula to determine how much to move an adjustable sight or file a fixed sight:

(Sight radius / Distance to target) (POI change needed) = Adjustment needed

All units must be the same. E.g., my rifle has a sight radius of 21.125" and 50 yards = 1800 inches. I needed to remove a bit over a tenth of an inch from the front sight to bring up the point of impact.

Something I noticed is that with this powder charge, ball size, and patch/lube combination, I can load a second shot without wiping but it's tough. After I get it zeroed I'll try with a liquid lube to see if that makes it easier. But I may look into a thinner patch for reloads while hunting, or bring a jag and patches wet with rubbing alcohol in my shooting patch when hunting. 

Tomorrow I'm planning to get together with a friend for some shooting and I'm bringing the Gemmer Hawken. Hunting season is coming up soon so I want to verify the zero get some practice in.