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lonewolf172

40 Cal
Joined
Nov 26, 2020
Messages
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Are there any ML experts here who knows what the measurements of the lands and grooves are for the .50 cal Investarm Gemmer Hawken are. I know the bore is probably .500-.501 but you need the other 2 figures to know what's the best size round ball and patch to use.
 
Are there any ML experts here who knows what the measurements of the lands and grooves are for the .50 cal Investarm Gemmer Hawken are. I know the bore is probably .500-.501 but you need the other 2 figures to know what's the best size round ball and patch to use.
I can't help you with the measurement. Most likely the barrel will like a .490 or .495 RB. I would start with the .490 and .018 cotton patch with your favorite lube.
PS....... I am NOT and expert!
 
It was explained to me expert (X-Spurt)
an X is a has been
a spurt is a drip under pressure
I will go foe experience every time
 
No matter, ya still gotta put in the range time and do it like all the rest of us....trying many many different combo's to achieve your rifles best load. Grains/brand of powder, thickness of patch, types of patch lube, weather to chew leaf or fine tobacco while shooting etc. etc. It all will matter.
 
There is actually a bit of variation from rifle to rifle so it is impossible to say. I suppose it depends on the sharpness and wear on the rifling cutters when that particular barrel was rifled. I have 2 Investarms Hawkens, one shoots very well with a .490 ball and .018 patch. The other, that combination won't even start without hammering it in and deforming the ball.
 
No matter, ya still gotta put in the range time and do it like all the rest of us....trying many many different combo's to achieve your rifles best load. Grains/brand of powder, thickness of patch, types of patch lube, weather to chew leaf or fine tobacco while shooting etc. etc. It all will matter.
You, Sir, have hit the percussion cap right on the cone in a manner of speaking.
We are all in the process of re-inventing a very old wheel.
Like most of us my knowledge comes from try and fail so try something different. We all learn from experience.
Somewhere I saw "A smart man learns from experience, a wise man learns from others experiences"
Stay safe and make smoke
Bunk
 
Are there any ML experts here who knows what the measurements of the lands and grooves are for the .50 cal Investarm Gemmer Hawken are. I know the bore is probably .500-.501 but you need the other 2 figures to know what's the best size round ball and patch to use.
Since you, @lonewolf172, don't have the Gemmer Hawken in hand to do the measurements, there is going to have be a bit of speculation going on in my reply as I don't have the rifle at hand either. Historically John Gemmer worked in the Hawken Brothers' Gun Shop and eventually bought it along with the rights to use the Hawken Stamps as well as his own stamps. He built rifles with the same specifications as the original rifles. He probably built a lot of them himself.

I don't have the data for the Investarm Gemmer Hawken. I did take a look at the data in the Gun Digest's "Third Black Powder Loading Manual" from the mid 1980's. Got me there, @Cpt Flint. Have to look for the Investarm rifles as they are identified by the importer. The Lyman Great Plains Rifle which looks to be the predecessor of the Gemmer Hawken has groove that are 0.010" deep and a land to land bore of about 0.500". Sam Fadala used a 0.490" ball and 0.013" linen patching. Other Investarms rifles have groove depths of 0.005"

Now it will still require load development with the multiple sizes of ball, patching, lubrication and powder charge to determine the bet load. Even with published data it will still be necessary to do the measurements to establish a starting point.
 
I think you have your answer from several people. Investarms lost the Lyman contract and is selling the rifle formerly known as a GPR as a Gemmer. The odds of them making an entirely different barrel are zero. A search on Goggle will quickly tell you the bore specs. for a GPR. But, at some point, you're just going to have to shoot it to see which combination of ball, patch, and load it likes.
 
I have a Charles Daly Investarms Hawken, I believe is a 1985 build. I use a .490 ball, 80gr of 2f Goex, and a .018 pillow ticking patch either drylubed with Ballistol and water 6:1 or with Mr. Flintlocks lube.
 
As said, there are variations. To find an "expert" with that specific knowledge you first must define what makes one an expert. Best and simplest way to get your question answered is to measure the lands and grooves. To do that, put a brass rod down the barrel, hammer an oversized soft lead ball into the muzzle about one inch. Turn the rifle with muzzle down and pump up and down until the brass rod bounces the ball back out. Using micrometers, measure what you want from the ball.
 
This is what I do. Cut strip of your patching material 1 1/2” wide wet middle of cloth drive down bore 6” with short starter. And pull it out with strip hanging out of muzzle. And follow drawing below. I use pillow ticking from the fabric store and rip or cut a strip.
then compair to photo below copied from Lyman’s Black Powder Handbook 11th printing 1996. This what works for me.
7EE4BF26-759B-4C53-A34F-13C5EA0687D4.jpeg
 
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