Optimum .50 cal barrel length for velocity

[brasschaser]

What's the best barrel length in terms of velocity for a .50 using ~100gr charges? 

Has anyone done some chrono work?  I would think your velocity would peak in a .50 barrel rather quickly due to the large volume.

[Keith Lewis]

You have to be more specific. Different powders have different burning rates. Tripple Seven for instance is a rather fast powder and will reach maximum in shorter barrels. Black Mag'3 is a fairly slow powder and will require longer barrel length to reach maximum.  Black Powder is also fairly slow so the longer barrels will get higher velocity with 100gr. or higher charges. It is also somewhat dependent on the bullet construction and weight (sabots vs. conicals and light vs. heavy). You may have noticed that most "magnum" muzzleloaders have 26-27 inch barrels. I believe that the manufacturers know that with charges of 100-150 grains the shorter barrels will not use all the powder and the longer barrels are required to get any gain from the additional powder.

[brasschaser]

Thanks.  I'm totally new to muzzleloading and have just been window shopping.  So I guess there is some sense in going with a 26"+ barrel.  I just went w/ 100 grains as a starting point as most posts I've read recommend loads right around there.  I gotta wonder however just how much velocity you'd lose going w/ a 100gr charge of pyrodex and a conical in a 24" instead of say a 29" barrel.  That's great to know that there's that much variation among suitable muzzleloading powders to utilize barrel length.

You have to be more specific. Different powders have different burning rates. Tripple Seven for instance is a rather fast powder and will reach maximum in shorter barrels. Black Mag'3 is a fairly slow powder and will require longer barrel length to reach maximum.  Black Powder is also fairly slow so the longer barrels will get higher velocity with 100gr. or higher charges. It is also somewhat dependent on the bullet construction and weight (sabots vs. conicals and light vs. heavy). You may have noticed that most "magnum" muzzleloaders have 26-27 inch barrels. I believe that the manufacturers know that with charges of 100-150 grains the shorter barrels will not use all the powder and the longer barrels are required to get any gain from the additional powder.

[Keith Lewis]

If you hunt areas that do not allow shots much over 100 yards almost any length will do. Usually for deer sized animals at 100 yards or less powder charges of 80-90 grains with 300gr. or lighter bullets will do just fine. That load will shoot well out of a 22 or 24 inch barrel. When you want to shoot higher loads like for elk or distances over 150 yards the longer barrel might be more necessary to burn the additional powder needed for that kind of performance. I think you will find that few actually shoot the max loads as they are usually not the most accurate and in most cases unnecessary.