Cayuad: How does one determine the rate of twist of a barrel? I have closely inspected the barrel and do not find any markings. My rifle was hand produced by an individual smith now deceased. Is the 1-48 twist rate some sort of industry standard or is there a quickie test I can use to find out? Regarding sabots...I assume it is plastic residue that accumulates after firing along with unburnt powder...any special solution you suggest to swab with after sabot shot?
To determine the twist of the barrel and simple way is... Cover the muzzle of the barrel with masking tape. Cut the hole out for the bore of course. Now mark an + using one point level to the front sight of the barrel. You have now cut the barrel in to four equal parts on the circle.
Now put a tight fitting patch on a loading jag. I like to oil the patch just a little. Push that to the bottom of the barrel. Now level to the muzzle wrap a piece of masking tape around the ramrod. With a marker, put a dot where the front sight is on the rod masking tape. Slowly pull the ramrod up the barrel, letting the patch turn with the rifling. When that dot reaches a quarter of a turn or half of a turn you can stop. Measure the distance the ramrod has moved up, out of the barrel.
Remember a 1-48 twist means a projectile will make one complete turn in the rifling in 48 inches. A 1-28 means it would move 28 inches in a barrel to make one turn. So if your projectile moved upward out of the barrel, lets say 12 inches to the quarter mark, 12x4 (being 1/4th of the barrel)=48 that would mean the twist of the barrel is 1-48. If it moved 7 inches, 7x4=28 so it would be a 1-28. 16-1/2 would be a 1-66 twist. And so on.
The problem with this method is it is not exact, but it will give you an "approximate" twist. Most barrels are 1-70, 1-66, 1-54, 1-48, 1-32, 1-28, 1-24, or 1-20 depending on make of barrel and caliber of barrel.
Your rifle being hand produced will be really interesting. Some of those hand made barrels were anyones guess of twist. I will "guess" if it is a traditional style and a long barrel, it will be a 1-70 or more. A lot of the early custom gun makers made excellent roundball barrels. Although it might be a 1-48. 1-48 is a do all twist. So a lot of gun makers go with that twist because it allows the shooter to choose from a lot of different projectiles.
If your rifle is a 1-70 (lets say the ramrod moved about 17 inches) then it is a roundball rifle. Forget the conicals and sabots. Stick with roundball. Unless it is a military rifle with a 1-70 twist and shallow rifling. These were made to shoot ball and minne.
