Questions about Numrich Barrel?

[Captjoel]

I recently picked up a NOS 7\8 straight full octagon 42" barrel that is unmarked but was told came from Numrich Arms. The barrel is a 45 caliber with very shallow slow twist grooves. Thinking about using it for a southern flintlock rifle build but would appreciate anyone who has ever shot a rifle with such a barrel and how it performed? Also, what loading recommendations for shallow groove rifling?

Many thanks in advance! Joel

 

[Grenadier1758]

@Captjoel, we need some more information. What is the land to land diameter of the barrel? What is the groove depth? What is rate of twist?

I try for a ball that is 0.005" under the land to land diameter. I want a patch thickness that compresses to the groove depth + 0.0025" in a slow twist of 1 in 48 or slower. Slower twists will likely require more powder to get the velocity up and send the ball toward the target with a slightly more stabilizing rate of revolution. Powder would be 3fg using 50 to 65 grains of powder to propel the ball. I use a damp patch lubrication of 1 part Water Soluble Oil to 7 parts of water for a 0.017" thick cotton drill patch. This load will require using a short starter to load the ball.

I have a Numrich (?) barrel that is 1 1/8" across the flats with a 1 in 56" twist. It shoots round ball quite well. You will likely have very sharp lands and the first shots will shred the patches. It took quite a few rounds to smooth the barrel out. At first linen patches were required. Load development will be the final decision maker for your barrel.

 

[andy52]

I have one of the Numrich barrels that was never installed. No breach plug and no drum. The stock pins are drilled through the bottom of the barrel it has no tenons. I'm pretty sure this was a barrel for their "Minuteman" model.

 

[Rifleman1776]

Unmarked? It may not be a Numrich. I have had several and sold them. Don't recall the twist but rifling was deep enough to not be called 'shallow'. Like any ml rifle, you must work to find the ball/patch/lube/charge combo that works best for you. If it is a Numrich, it may require a ball smaller than .440". For one of our rifles I had a .433" mould, others were OK with .440" balls. Start about 45 gr. real bp and work up to get best grouping.

 

[Grenadier1758]

By all means measure the bore to determine the land-to-land diameter of the bore. You need to know that before staring with the selection of a ball diameter.

 

[ohio ramrod]

I have numrich arms barrels on my swivel breech 45 caliber . It prefers .435 balls .015 patches. It is very accurate!