I checked Winchester's webpage where they advertise the velocity of their 110gr .357 Magnum load at 1295 fps with a 4" barrel.

Does anyone know what the velocity would be with a 6" barrel ?

Barrel length is only one factor, the gap between the cylinder and the forcing cone is also critical. The tighter it is the more th velocity goes up. There is a point though were you compramise reliability due to fouling of the cylinder face however. Any good gunsmith can alter the gap for you.

BrenLover

I was looking for a rule of thumb measurement such as 1" = 50fps. Just curious if anyone had any ideas.

If you care to extrapolate:

I just chronographed this today...

15 gr. of 2400 in my .41 Mag with a 210 gr. bullet according to the books should be about 1250 ave. out of a 6 inch barrel.  In my case I got and ave. vel. of 1180 out of my Ruger Blackhawk's 4 5/8 or 4 3/4  inch barrel.  Of course there are many other factors that may cause your mileage to vary.

So if my internal barrel Dimensions, cylinder gap, and chamber dimensions were the same as the test guns dimensions, I lost 70 FPS for and 1 1/4 or 1 3/8 reduction in barrel length.

(I just can't remember the exact length of my barrel off the top of my head.)

Kent

Which works out to a convenient 1"=50 or 56 FPS in my case (depending on barrel length).

Kent

I just bought a S&W 686 with the 6" barrel and was curious about any velocity gains over a 4" barrel. I realize it's not going to be allot over the 4" barrel and that with a revolver there are many variables that come into play.

The best thing to do is to clock it on a chronograph, which I don't have.

Thanks to all who responded...