.58 Barrel Length vs Velocity

[Good Cheer]

How much difference does 26" versus 32" length make in the velocity for round ball and conicals in a .58?
Any you fellas checked it out on a chronograph?

[northmn]

Lyman catalog:
26" 2f GOEX 80 gr RB 1039 575213 minnie 948 505gr
32" SAME 80 gr RB 1177 575213 924 505gr

Why the minnie was a touch slower in the 32" anybodys guess. Sometimes that happens. In another test you might get different results. Not a lot of difference.
In a 22" barrel they had 1075 for the RB and 889 for the minnie.

DP

[Baron von Trollwhack]

It makes a difference for sure, but neither deer, paper targets, or frangible targets think it is of significance BvT

[Good Cheer]

Lyman catalog:
26" 2f GOEX 80 gr RB 1039 575213 minnie 948 505gr
32" SAME 80 gr RB 1177 575213 924 505gr

Why the minnie was a touch slower in the 32" anybodys guess. Sometimes that happens. In another test you might get different results. Not a lot of difference.
In a 22" barrel they had 1075 for the RB and 889 for the minnie.

DP

Looking at the velocity on the minie I can't help but wonder if the additional barrel length might allow the minie to be loaded with heavier charges without blowing the skirt.

[northmn]

Did a little more checking and looked up a couple of other minnies Lyman tested:

Used 80 grains as a comparison:
575602 26" 875 32" 1049
Go to the 100 grain Charge on the 575213 26" 1071 32" 1132
60grain charge 26 753 32 814
530 gr 57730 Stake Buster 26" with 70 gr 754 32 754 They were the same
575602 120 gr 26 1123 32 1263

As a rule the longer barrel does give a little more velocity and may gain more in heavier charges, but that is a very general rule as can be seen with these results. I have read more than one report where someone shortened a barrel and found a gain in velocity. Something as simple as a change in nipples during the test or burn out could explain the results. They had similar results with a 36 round ball test where the 32" was about the same velocity or just a touch slower than the 28". When lengthened a little more, it gained. At 20 inches it still performed well.

DP

[10 ga]

I think the longer barrels give a better burn of coarser powder and coarser powder produces less pressure. I think. My head hurts! 10

[northmn]

The whole barrel length issue is interesting. I build to original style and do not pay much attention to barrel length otherwise. Many of the original guns had barrels over 44" long, but if you look close the long rifle was kind of a dead end in firearm development. One of our first military rifles, the Harpers Ferry had a 32" barrel. The English Baker was 30" and the Hessian rifle was shorter. It was not long after that that the trend was toward shorter barrels. Most think that the long rifle was a result of the very poor domestic and home made powders used at the time and as the domestic powder got better it was not needed. Europeans had better powder and did not use long barrels. I used a 32" barrel on my latest creation and like it. With heavier bullets the differences may be less.

DP

[Geraldo]

How much difference does 26" versus 32" length make in the velocity for round ball and conicals in a .58?
Any you fellas checked it out on a chronograph?

Chronos are useful, but the only thing it will tell you for sure is what happened in the barrels tested. As they say, your mileage, or in this case, velocity, will most likely vary.

I'm with BvT, a .58 is serious medicine with RB or boolit, and a hundred FPS one way or the other really won't matter.