Gents looking at some light loads for 357 cast 158grain in a rossi 92 Hodgon has the following loads for 10" barrels.

Question I have is will velocity be much different in a 24" carbine?

Normally for rifles there is signficant increase, but given these are extremely very light powder loads I assume its burnt quickly.

Trail Boss 3.2grains 754fps 16500cup

IMR PB 3.5grains 845fps 12,200 PSI

Titegroup 4.5grains 1,028fps 19,300 CUP

CFE Pistol 5.3grains 1,123fps 18,100 PSI

The plan would be to have one of these reach handgun factory ballistics for 158 grain( about 1250fps) but for all I know they might even be slowing down in a 24" barrel....

Be careful with light loads and jacket bullets in the rifle. I have had bullets shed their jackets which can ruin a barrel if not caught in time. At those velocities cast should work great. I have had good luck with AA#5 in my .25-20, you might give it a try.
C.G.B.

you'll still pick up 100 fps or so.
that CFE-pistol powder looks like it would be close to your targeted velocity.

With a max load of H110 and 158 jacket I get 1880 out of my 18 inch carbine.

I have a 22 inch single shot 357 I use 2.5grs of red dot with a 158grs swaged bullet for 820fps.

It is very quite less then a 22LR.

Very accurate one hole groups at 50 yards

The research I read it takes a really long barrel before you start losing velocity.

Some of the real light 22 loads like the CB caps or the super quite stuff takes less.

Getting 1250 out of a 357 carbine is child's play.