Barrel Twist/Accuracy/Projectile

[PAHUNTER105]

I am rather new to this black powder hunting. I was wondering if someone can explain the whole twist,acuracy load etc? I would like to know more, I am a learning junkie when it comes to hunting and was wondering about this issue. I have a Thompson Center 50 cal and a traditions 50 Cal. Was wondering which loads would be best for me. I hop this is not too broad of a question. Any help is appreciated.


Thanks,

Kelly

[cayugad]

The main thing is to know your rifle's twist in the barrel. From there you can figure what it might shoots. For instance... caliber also makes a difference, so I will address a .50 caliber for you.

1-60 or slower like a 1-101 would be a round ball shooting rifle.
1-48 is a roundball, conical, or sabot barrel. The trick is finding which one
1-32 used to be called a conical shooting barrel, but they will also shoot sabots. Even roundball is you lower the powder charge.
1-28 or faster like a 1-18 are your sabot and conical shooting barrels. Many of the modern 1-28 will shoot sabots real well.

Then you have to look at barrels with some special cut to their rifling. That too can decide what the rifle will shoot. So like I said, know your rifle.

[spaniel]

Basically, the longer the bullet is compared to its caliber (of the bullet, not the barrel), the faster the twist must be to stabilize it. So for each caliber, there is a maximum length of bullet that, say, 1 1-28" twist will stabilize. If you move up in caliber, from say a .40cal Shockwave to a .45cal Shockwave, the you can use a longer bullet because the diameter has gone up.

The practical implications of this are exactly what Cayugad has shared.

As for load development, that is a much less scientific explanation -- all guns, even those of the same model -- are individuals. Some will shoot a load will and other guns of the same model will not. All you can do is experiment until you find what works best in your particular gun. Usually, start at 80-85gr and work your way up in 5-10gr increments until the most accurate load is determined. Few guns shoot accurately at their full rated charge, especially with lighter bullets.

[lemoyne]

Twist = 150 X D2/L
Where:
D = bullet diameter in inches
L= bullet length in inches
150 = a constant
This formula gives maximum length of a projectile at muzzleloader normal speeds.
For instance a .45 caliber 1-48 twist would shoot best with a projectile under .625 this could include a Patch round ball, a real bullet or a sabot-ed bullet that was short enough. If they are longer than the length that will stabilize you will lose accuracy and may even tumble if it way to long.
This changes with caliber for instance a 50 caliber 1 in 48 twist will take a bit longer bullet .75 and shorter.
I hope this helps you understand better. Lee