Pistol rifling

[George91946]

Hello. I greatly value your expertise and opinions. My question is what range of rifling would you expect in a pistol barrel?

Years ago, I purchased a rifled 0.5 cal pistol barrel from a track of the wolf close out sale. Cost me $20.00 or so. Had it sitting around, and finally got time to use it for building a left handed flintlock. Bought a lock, breech plug and some furniture from Track, and a block of maple from the lumber yard, and whittled a pistol. Came out ok, and I tried out some rudimentary carving so it looks unique. I've been learning to use it, but accuracy is not as good as I'd hoped yet. I measured rifling at 1/4 revolution over an 8.5 inch distance, which equates to approximately 1:35. Is this an appropriate rifling ratio for a pistol? I'm shooting 20 grains 0.490 cal patched round ball, 3F goex, and 0.020 mm Patch. Bore is bright, and no pits or obstructions. Inletting is tight, and I also acraglassed the bed before final construction. Gun feels robust and solid. Typical problems with L & R lock, but mostly fires ok and is fast.

Thanks

Lisle George

 

[biliff]

1:35 seems slow for a .50 pistol. Believe they usually run around 1:20 for that caliber.

I'm shooting .44's with 1:18 and using 20 gr FFFg. You might try bumping your charge up. A little more velocity might help with the slower twist rate.

 

[pecos clay]

My .54 is 1:20 green river barrel.

 

[George91946]

Thanks:

How much do you think that the slower tiwst influences accuracy of the piece?

 

[Dphar]

Hello. I greatly value your expertise and opinions. My question is what range of rifling would you expect in a pistol barrel?

Years ago, I purchased a rifled 0.5 cal pistol barrel from a track of the wolf close out sale. Cost me $20.00 or so. Had it sitting around, and finally got time to use it for building a left handed flintlock. Bought a lock, breech plug and some furniture from Track, and a block of maple from the lumber yard, and whittled a pistol. Came out ok, and I tried out some rudimentary carving so it looks unique. I've been learning to use it, but accuracy is not as good as I'd hoped yet. I measured rifling at 1/4 revolution over an 8.5 inch distance, which equates to approximately 1:35. Is this an appropriate rifling ratio for a pistol? I'm shooting 20 grains 0.490 cal patched round ball, 3F goex, and 0.020 mm Patch. Bore is bright, and no pits or obstructions. Inletting is tight, and I also acraglassed the bed before final construction. Gun feels robust and solid. Typical problems with L & R lock, but mostly fires ok and is fast.

Thanks

Lisle George

66 and 70" twist barrels will shoot under 2" or so for 5 shots at 25 yards when trimmed to even 6" and used in pistols. The longer barreled versions will be surprisingly accurate to 100 yards or so.
If the barrel is a GM it should be a 20"twist, which I think is too fast for a RB gun. But there are other pistol barrel makers and I an not familiar with all the twists used.

Dan

 

[Dphar]

I did not properly read the original post and missed the powder charge being used. I am shooting 45 grains from a 54 right now and was shooting 55 from a 58 I built for a friend. I used to shoot 60 from a 66 twist 54 pistol. At 50 grains and over a 50-58 pistol is fully capable of killing deer and will approach 44 mag muzzle velocities.
20 grains is so light as to be marginally dangerous. I once shot either 15 or 20 from a 58 smooth bore English "overcoat pistol" I shot at a block of pine and the ball bounced back and whacked me on the shin very much like hitting it a lick with a hammer. I would not use less than 30 in a 50 if I wanted it to be useful. Very often RB guns, either smooth or rifled don't like light loads of powder.

Dan

 

[George91946]

Thanks
Range opens again tomorrow. I'll bump up the powder load to 30 grains and retry. I have trouble holding pistols with heavy recoil so I went with the lighter load initially.