original rifle caliber selection.

[cheatherly]

I'm not sure if this is the correct area to post this question. I see many odd, to todays ideal, calibers in original muzzle loaders. For example in the book Thoughts on the Kentucky Rifle in it's Golden Age, I see many 43's 47's 67's 59's etc. I am curious, how did the gun makers select the caliber of their rifles. Where there standards as to let's say, a rifleman going to a store to buy a box of 51 cal round balls? Or did everyone cast? In my reading, I haven't seen anything pertaining to why the gun builders selected one caliber over another (excluding the obviuos; big game/small game/target buns). As a second part to my question, I know the gun builders rifled their own barrels but did they drill the blanks also, could that effect the caliber in any way?

 

[tg]

The norm at the time was to make a bore size in balls to the lb. thus what we consider as odd calibers, I think it was standard for the smith to make a mold for the gun. Also freshing out was common which could increase the bore a bit in time if enough iron was left to deepen the rifleing.

 

[rich pierce]

Good question.
We are now pretty sure that the majority of rifle builders did not forge their own barrels. They purchased them, often as smoothbore barrels, and rifled them- or not. They would buy them of a certain gauge or balls to the pound. There was some variability because of reaming the barrels after drilling out. To get the interior smooth might require taking more out of the bore, depends on the weld, imperfections, etc.

Then as TG said, with re-freshing and etcf from time to time, the barrel could enlarge and need a larger ball.

The other thing we often forget is that old-time makers often funneled the muzzles somewhat and those measuring the bore can be fooled if they do not go in an inch or two to make the measurement.

A smith could ream out a bullet mold with a larger cherry to make a larger ball as the bore enlarged with successive freshenings. Not a problem in a non-military situation. But if ammunition had to be shared, common caliber/gauges had to be maintained.

 

[Twisted_1in66]

I'm not sure if this is the correct area to post this question. I see many odd, to todays ideal, calibers in original muzzle loaders. For example in the book Thoughts on the Kentucky Rifle in it's Golden Age, I see many 43's 47's 67's 59's etc. I am curious, how did the gun makers select the caliber of their rifles. Where there standards as to let's say, a rifleman going to a store to buy a box of 51 cal round balls? Or did everyone cast? In my reading, I haven't seen anything pertaining to why the gun builders selected one caliber over another (excluding the obviuos; big game/small game/target buns). As a second part to my question, I know the gun builders rifled their own barrels but did they drill the blanks also, could that effect the caliber in any way?

The method used to make a rifle barrel was tedious and accounted in the main for the difference in price between a smoothbore and a rifle.

The rifle barrel maker started out with a flat piece of wrought iron that he heated in the forge. He places this on a set of cupped forms and starts hammering the flat piece into a U shape. He then puts a mandrel in the middle of the "approximate" caliber he wants to make and continues Hammering the U closed around the mandrel into an O. This is called hammer welding and when completed successfully, there is no seam in the barrel.

Then the barrel maker removes the mandrel, reams it out and rifles it. Then he trims the outside of the lumpy octagon into the clean shape of the finished barrel. I took/takes a crazy amount of time and energy to make one barrel.

Because of this hammer-welding/reaming/rifling process, it was very difficult to get the barrel calibers to consistently come out the same caliber. So, every rifle (or barrel) sold included a bag mold to cast the appropriate size ball for that barrel.

Here's link to Toad Hall showing the hammer welding process on a pistol barrel.

Twisteed_1in66 :hatsoff:

 

[cheatherly]

What an amazing amount of work. :shocked2: Thank you for a great website. :thumbsup:

 

[Bill Hall]

Hey good post Chapter. I've also wondered how these seemingly oddball calibers came to be, I just never thought to post a question here. Though I won't even speculate on any answers, I'm going to sit here and read the answers and learn along with you, and we've already got some good answers. Bill