Twist rate for 32-20

The standard twist for the .32-20 was one turn in 20". If your interest leans towards traditional bullets, loaded to black powder velocities, that works well.  But if you want to experiment with heavier bullets of more than 115-grains, especially at quiet, subsonic velocities for low noise, the rate of twist used for .32-20 REVOLVERS being one turn in 16", is a better choice. I don't own a .32-20 anymore, because I found that in either rifles or modern, strong revolvers, that I could do everything the .32-20 would do, with the .32 S&W Long, using smokeless powder. S&W Long brass is less expensive, more plentiful and sturdier.

I have fooled with .32 S&W Long in rifles of various twist rates, with both heavy and light bullets, both having traditional “.32 cal.” dimensions and tighter “.30 cal.” dimensions.

I came to the conclusion that as long as you have a “good” barrel with properly cut, concentric chamber and use appropriate loads with bullets which “fit", the twist and barrel dimensions don't matter within reason.  A faster twist such as 10” to 14” is more flexible with heavier bullets at low velocity and a slower twist of 16” or longer is better for lighter bullets at higher velocity and with black powder.

My current interest in the .32 S&W Long in a rifle is to approximate the payload and velocity of .38 Special standard velocity (not +P) loads from the .32 S&W Long case. This closely approximates the ballistics of my .30-'06 “Gallery” loads, but with a case full of powder in the tiny case.  I am using a 10” twist barrel fabricated from an M1 Garand pull-off, cut off at the gas port and chamber neck, turned down and fitted by John Taylor onto a tiny H&R .44/.410 shotgun receiver.  The “Bunny Gun” with 18” barrel weighs 4 pounds and shoots 2” groups at 50 yards with iron sights with most loads.

A charge of 5.6 grains of Alliant #2400 powder with the Accurate 31-155D flatnosed bullet, seated and crimped into the crimp groove is compressed. Velocity from an 18” rifle is 1030 f.p.s., sort of like Eley Tenex On Steroids. The same loads from a late 1960s era COlt Police Positive Special in .32 Colt New Police shoots to the sights at 100 yards, is accurate enough to hit a 12” steel gong, and gives 720 f.p.s. The same load from my 2” Detective Special of similar era, shoots to the sights at 50 yards, hitting the 12” steel gong with a 6:00 hold, and gives 645 fps.

If building a new, custom rifle for small game and recreational shooting with cast bullets, either the .32 S&W Long or the .32 H&R Magnum are good choices.  If you have a pull-off .30 cal. rifle barrel with bright, clean bore in any rate of twist, you can make it work.