38 extra long twist rate

[j.howardcycles]

Hello;
Having a barrel lined for 38 extra long. Having a hard time finding the twist rate for it. Cartridges of the world states 1-36. The barrel is in 38 long now and the rifling twist rate looks much faster than that. Both of the cartridges used the same bullet weight -148-150 gr. Not much of the original rifling left to get a reading from. Greenhill formula has it a 1-24 with 1160 velocity using 31 grains of 2f black powder. Anyone have a idea ?
Thanks
John

[Regnier (gunrunner)]

John;

Brophy states in the Marlin book, on page 496 that the .32 Ballard has a twist of 1 in 20 inches.
The 7th Edition of Ammo Encyclopedia states the the .32 Long uses a twist of 1 in 18 3/4 inches using bullets of 125 to 150 grains.
Good luck.........

[marlinman93]

Hello;
Having a barrel lined for 38 extra long. Having a hard time finding the twist rate for it. Cartridges of the world states 1-36. The barrel is in 38 long now and the rifling twist rate looks much faster than that. Both of the cartridges used the same bullet weight -148-150 gr. Not much of the original rifling left to get a reading from. Greenhill formula has it a 1-24 with 1160 velocity using 31 grains of 2f black powder. Anyone have a idea ?
Thanks
John

What groove diameter and chamber is your gunsmith going to use for the liner? If he does the original bore/groove diameter it will be a .375" and require the bullets to be a heeled bullet. If he does a modern version it will be a .357" groove, and use shortened .357 Maximum brass and easy to find .357" bullets.
The issue is finding a liner for the smaller bullet that's the right twist rate for a rifle. The other issue is once it's chambered to accept shortened .357 Maximum brass, anyone in the future could drop a .357 Magnum cartridge in it, and quickly blow up the cast #2 Ballard! So need to be very careful with this reline, and what you plan to proceed with on a liner and chamber.

[j.howardcycles]

Thanks for the reply's. He makes his own liners at any twist rate needed. So no problems there. It is going to be in .357 Maximum. Black powder of course. The barrel will be marked for 38 extra long.