Round Ball Stabilization?

[El Lobo]

Hey Guys,

What is the minimum rate of twist (rifling) that will still stabilize a round ball?

Specifically, I'm looking at a percussion with 1:48 twist and a  .620 bore.    All I know about these things is that a ball rifle usually has a 1:66 rifling.

Your comments and knowledge are needed!!!

Lobo in West Virginia

[flintlock]

My .54 is 1-72...My .40 is 1-48...

A .62 with heavy charges should be a bit slower than my .54...Especially usung heavy hunting charges...

That being said..As you know each gun is different...Even though a 1-48 isn't "optimum" for a .62, if you worked with it you should be able to find a load that groups well...The original Hawkens were
1-48, and most ran .50-.54 caliber...

[roundball]

While it's "generally" true that the larger the caliber the slower the twist for a round ball...BUT...depending on what you'll be using it for and the absolute degree of accuracy you "must have", are really the determining factors.

The mantra...often repeated blindly by a lot of people who read posts on the Internet...that round balls must have slow twists to be accurate is incorrect on it's face because it doesn't include qualification for which caliber is being discussed...because different caliber sized balls influence the twist requirement, "across the board generalizations" like that are wrong immediately...too much of a generalization.

Looked at the opposite way, you'll hear people say 1:48" twists don't shoot round balls accurately...a flat statement...without qualifying it by caliber.....yet for example, the 1:48" twist IS the round ball twist for a .40cal round ball...as you might be able to tell...and as evidenced by my "signatiure line" below...the mis-information posted then propated throughout the Internet on this subject of round ball accuracy & twist is simply incredible.

People I know who own fast twist .50cal rifles of a more modern pursuasion have been shocked to find that round balls were so accurate in them...and again, what is accuracy...what are you going to use the RBs for and what accuracy "must you have"...are you on a competition circuit where you need a micrometer to measure the differences in group sizes to win...or are you enjoying the hobby at a range and/or deer hunting where 1"-2" groups at 50yds are perfectly fine, etc.

I had a Green Mountain .62cal Flint smoothbore barrel that Ed Rayl in West VA. just finished rifling for me...UPS should deliver it this week...when I called him a month ago to arrange this, he asked what I'd be using it for, told him playing at the range and deer hunting here in the East...he said ".012" square bottom grooves with 1:72" twist".

While the .62 you referenced is a step faster twist at 1:48", if you're mainly going to use it at the range and deer hunting, I'd suggest a good snug patch ball combo and I'll bet lunch you'll be more satisfied with it's accuracy.

Let us know...

[El Lobo]

Mr. Ball,

The gentlemen who currently owns the rifle says ....

quote....".62 Hunter - 1:48 at .620 bore bullet guaranteed to shoot a 330 grain lead round ball under an inch and a half at 100 yards with 90 grains FF"....  unquote

For me, this rifle would be a Hunter.....deer, bear, and hogs.....I like to pull the trigger and see the critter drop to the ground.   As I said earlier, I'm not any kind of expert on the subject, only that the rate of twist seemed a bit fast for this bore.

Lobo in West Virginia

[roundball]

quote....".62 Hunter - 1:48 at .620 bore bullet guaranteed to shoot a 330 grain lead round ball under an inch and a half at 100 yards with 90 grains FF"....  unquote

Well, there you go...

Similarly, from the bench my personal groups range in the 1+7/8" to 2+3/4" with a TC .54cal 1:48" barrel using full power hunting loads...that's the largest caliber 1:48" I have for comparison.

[Will Bison]

My .62 smooth gun stays in eight inches at 100 yds. So putting some spin on it can't hurt. A 1-48 is not that fast and it's the twist the Hawken Boys used.

My .62 Fusil has taken a Bull Buff down to Quail. I loaned my gun to a fella in WY who wanted to drop a Buff, he said the 330 grain RB did the job at about 75 yards, give or take. He sent me some autopsy photos, jumpin juniper, did that ball do some damage. He backed the ball with an enormous charge of BP, well in the triple digits.

I think for just range shooting the 1-48 will be fine for 900-1000 fps. That's still a "cannon ball" downrange. I'm thinking perhaps 60 grains of BP as a start and work up or down.