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Discussion Starter · #1 ·
I have a .50 cal flintlock reproduction through which I have been shooting .50 cal lead round balls over 85 Grains of black powder with buckhorn iron sights. My accuracy seems to run about 2-2 1/2 inches at 50 yards up to about 4 inches at 100 yards.

I recently picked up some 300 gr Hornady SST sabot and 385 gr Hornady Great Plain lead conicals to experiment with this spring....couple of questions:

Should I patch the conicals as I do with the round balls? Suggestions as to where to start with a reduced powder load for testing purposes?

Any suggestions as to how to modify the powder load for testing with the sabot bullets? Any other loading tricks that are unique to sabot projectiles?

Thanks in advance for your input.

Brad4
 

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No you do not patch the conicals. Just make sure they have an application of lube to their outside if they have lube grooves. Powerbelts and some of the modern conicals like Thor FPB's, do not need to be lubed. Since a conical is much heavier, they will have a rainbow trajectory. So start your loads out around 80 grains. That actually with a conical is a good hunting load. I shoot a 460 grains with 70 grains of 3f powder and that is my deer load. I get complete pass through with that little bit of powder.

With sabots, start your testing at 80 grains. If your rifle is a 1-48 you do not want to push them so hard that the sabot start to slide over the rifling. I shoot 80 grains and a 250 grain XTP in a sabot out of a 1-48 barrel with some amazing accuracy. Be sure to load the projectile and sabot as one unit, and it might be necessary to swab the bore between shots.
 

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Discussion Starter · #3 ·
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?
 

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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.
 
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