How heavy or long can a cast bullet be shot in a .311 1x20 twist barrel

[Frank46]

Title basically says it all. I have a .311 barrel blank and stamped on the breech end is the diameter .311 and the twist 1x20. So for you who are more gifted than me with math, how long or how heavy a cast bullet at roughly 1500 fps can I shoot out of this barrel. Cartridge will be the venerable 32-20.
Thanks,Frank

[Mk42gunner]

Find a copy of the Greenhill Formula and plug the numbers in.

I admit to some curiosity on this, and my guess is a ~120 grain 3118 will be awful close to optimum.

Robert

[RPRNY]

According to Greenhill, 130 grs. Of course, you could get as much as 150 grains depending on bullet design and range. Given 32-20 was a popular woodchuck rifle, heavies not needed. Sounds like fun.

[Frank46]

After many years I finally have a winchester low wall receiver coming my way. I've had all the internal pieces, stock and forend and shot out barrel. Seriously thinking of getting the old barrel relined to 32-20 with a slightly faster twist but did find a .311 1x20 twist barrel blank in my stash. So that is why I posted this question. The blank will need some trimming at the muzzle end but won't be anywhere near the 28" like the original winchester barrel. The barrel has a couple marks from what looks like a pipe wrench so not a pristine example. But good enough for me. And thanks for all the responses. Frank

[LCN]

I have two original old 3118 Ideal single cav moulds. Sorry won't part with either. Glad I had them when I bought my Ruger 32 H&R Mag. when Ruger came out with it. As far as I know this was the most popular bullet for the 32-20 used in both the Colt SAA and the Winchester.
One side note. Years ago I wanted a two cav mould and was told that Ideal had made some and sure enough I was told by my local gun shop they had one. I took one of my bullets with me and found that the new two cav mould was cut using a different cherry than the old mould was. I didn't buy it.

[Scharfschuetze]

Your 1 in 20" twist is just perfect for your intended use.

I use the plain base 115 grain 3118 in my revolver loads for the 32/20 and I have an NOE gas checked version for use in my Marlin 1894 carbine. The carbine has the 1 in 20" twist and it handles the 115 grain boolits quite well all the way out to 200 yards.

Good luck with the project.

[Frank46]

Well at least I have the lyman 311316 gas checked bullet mold, brass,dies, and some other goodies. Thanks again,Frank