Making 44 Mags into 38-40

[bouncer50]

I have a 1905 Colt SA in 38-40. I have a lot of 44 mag brass, But no 38-40 brass to use i know i can buy new starline brass. But the problem with 38-40 brass is the thin neck. 44 mag brass has thicker brass at the neck

[BK7saum]

Well other than your cases being 0.012" short and 0.008" too narrow at the base, it might work. Personally I'd juse spend money on new starline.

[country gent]

The thicker neck ( roughly .002 on a side or .004 total). may actually be a problem for you as rounds may not chamber with bullets of the correct dia and the added thickness. Being to small at the base may eventually blow out to fit. The to short will grow with the number of firings and sizing eventually also. I would be concerned with chambering issues and possible case head seperations. The old colts arnt high pressure guns so appropriate loads will take some time to form out. Also the 44 mag is thicker it entire length, more so the closer to the case head you get, so case capacity is going to be less On these cases.

[HABCAN]

Go Starline and bypass a LOT of problems.

[gwpercle]

Where's the fun in just buying Starline ?
You have the 44 magnum cases, you have the 38-40 dies , I say try a few out .
Go slow on the reforming, might do it in two or three passes instead of trying to reform in one pass. Then take a look at boolit/neck fitment , may require a bit of neck turning , on the other hand it just may work perfectly ! Loading at 38-40 pressures the 44 magnum case will certainly take the pressure.
The only question is will the 44 mag. rim .514 x .060 work. the 38-40 rim is .525 x .065.
I would say in a revolver it will work, a lever action rifle will have to be tried...go for it !
Gary