roashooter
Moderator
How many here will use PRB in their stainless steel, plastic stocked, shotgun primer, bolt action, high power scoped, muzzle loader?
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How Many Here Will Use PRB
- Thread starter roashooter
- Start date
How many here will use PRB in their stainless steel, plastic stocked, shotgun primer, bolt action, high power scoped, muzzle loader?
The twist on those is way too fast for a round ball unless you get the powder charge down to ridiculously low velocities.
How many here will use PRB in their stainless steel, plastic stocked, shotgun primer, bolt action, high power scoped, muzzle loader?
i use patched round ball in my scoped .54 caliber TC Fire Hawk rifle. The twist rate is 1/38". The rifle uses no. 11 caps rather than shotgun primers. The powder charge is 100 grains of Black MZ. Gun shoots patched round balls like lasers and i've killed numerous wild hogs with it.
Never bought into the patched rounds balls are only accurate when fired from slow twist barrels claim. So i did extensive testing with .50 caliber inline guns. Rifling twist rates as fast as 1/32" proved accurate with patched round balls: Maximum accurate powder charge with that rifling was 70 grains of JSG.
Never got the gun with rifling twist rate of 1/28" to shoot well with any reasonable powder charge.
Twist is not what makes a barrel accurate or inaccurate for balls.
Rifling geometry can sure have an effect though.
I used to make my own barrels back in Nevada years ago, and I made some to experiment with, having twists from 1-104" to as tight as 1-12" All were cut with .009" deep rifling and all were cut with grooves 2X as wide as lands.
All barrels were lapped to a very smooth internal finish and had no tight or loose spots.
There was no difference in group size at all. The 1-12" twist 50 cal still shot a ragged hole at 50 yards, just like the 1-76 and the 1-104 did.
Once a ball is stable, it's stable.
However the fast twist barrels would foul very fast, and the slow twist would not. So I would advise a slower twist for ball shooting just for that reason. As long as the bore is clean they were just as accurate.
But the idea of a tighter twist being inaccurate with balls is just not true.
The revere is true however.
If you try to shoot long bullets in a slow twist (say 1-56 or slower) you will have very bad performance, with some bullets even striking the paper sideways.
Gyroscopic stability if needed for any bullet, and long bullets being of 2X or more length to diameter, need a pretty good spin to keep them going nose forward.
With a 50 caliber barrel I made for a replacement for a 50-140 sharps I used a 1-22" twist with .005" deep grooves, cut with grooves as wide as lands, but with 10 degree angled sides. That Sharps came out very accurate when I was done.
The original barrel was twisted 1-38, and it was very tricky to get good accuracy from 500 grain bullets. The very long 750 grain bullets shot very poorly. With my 1-22" barrel the 750 grain bullets did very well.
I and the owner of the rifle were shooting poker chips with 750 grain bullets at 100 yards, where the old barrel would not keep them hitting the whole 24" paper.
So in a nut-shell, fast twists work with bullets and any twist works with balls as long as the grooves are deep enough to hold the ball/patch correctly and allow for enough thickness of the patch so it doesn't tear.
Rifling geometry can sure have an effect though.
I used to make my own barrels back in Nevada years ago, and I made some to experiment with, having twists from 1-104" to as tight as 1-12" All were cut with .009" deep rifling and all were cut with grooves 2X as wide as lands.
All barrels were lapped to a very smooth internal finish and had no tight or loose spots.
There was no difference in group size at all. The 1-12" twist 50 cal still shot a ragged hole at 50 yards, just like the 1-76 and the 1-104 did.
Once a ball is stable, it's stable.
However the fast twist barrels would foul very fast, and the slow twist would not. So I would advise a slower twist for ball shooting just for that reason. As long as the bore is clean they were just as accurate.
But the idea of a tighter twist being inaccurate with balls is just not true.
The revere is true however.
If you try to shoot long bullets in a slow twist (say 1-56 or slower) you will have very bad performance, with some bullets even striking the paper sideways.
Gyroscopic stability if needed for any bullet, and long bullets being of 2X or more length to diameter, need a pretty good spin to keep them going nose forward.
With a 50 caliber barrel I made for a replacement for a 50-140 sharps I used a 1-22" twist with .005" deep grooves, cut with grooves as wide as lands, but with 10 degree angled sides. That Sharps came out very accurate when I was done.
The original barrel was twisted 1-38, and it was very tricky to get good accuracy from 500 grain bullets. The very long 750 grain bullets shot very poorly. With my 1-22" barrel the 750 grain bullets did very well.
I and the owner of the rifle were shooting poker chips with 750 grain bullets at 100 yards, where the old barrel would not keep them hitting the whole 24" paper.
So in a nut-shell, fast twists work with bullets and any twist works with balls as long as the grooves are deep enough to hold the ball/patch correctly and allow for enough thickness of the patch so it doesn't tear.
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