Cartridge swelling

[rcmodel]

Any load you find published in any Hornady or other reloading manual is at our under SAAMI MAX pressure spec for the .357 Mag cartridge.

They do not make allowances for a carbine being stronger then a handgun.

Either set of data is below SAAMI MAX pressure and is perfectly safe in either gun.
Or it would not be in the reloading manual.

rc

 

[788Ham]

Not to start a ruckus here rc, just a couple of points.

Revo.- using 158 gr. bullet, Win. 296 powder-15.2 gr @1200 fps- using a 6" python.

Rifle- using 158 gr. bullet, Win 296 powder-15.1 gr @1600 fps- using a Rossi 16" barrel

Neither of these loads are MAX loads, don't think I'd want to use the rifle load in my Python, I'd never load my Python loads that hot anyway, even if it wouldn't hurt it.

 

[Sam1911]

Revo.- using 158 gr. bullet, Win. 296 powder-15.2 gr @1200 fps- using a 6" python.

Rifle- using 158 gr. bullet, Win 296 powder-15.1 gr @1600 fps- using a Rossi 16" barrel

Neither of these loads are MAX loads, don't think I'd want to use the rifle load in my Python, I'd never load my Python loads that hot anyway, even if it wouldn't hurt it.

Wait...so the revolver load is listed as HOTTER than the rifle load, but you wouldn't want to use the rifle load in your revolver? Color me confused.

The 400 fps difference merely comes from having 10" more barrel in which the bullet can accelerate under pressure of the expanding gas.

 

[Sam1911]

Here's the info currently listed at Hodgdon's site:

For "pistols":
158 GR. HDY XTP
Winchester 296 (OR H110)
Start: 15.0
fps: 1418
Pressure: 28,600 CUP

Max: 16.7
fps: 1591
Pressure: 40,700 CUP

They aren't listing Win. 296 under rifle loads.


Most of us believe that H110 and W296 are identical, though, so here, for rifles:
158 GR. HDY XTP
Hodgdon H110
Start: 15.0
fps: 1619
Pressre: 28,600 CUP

Max: 16.7
fps: 1757
Pressue: 40,700 CUP

Powder charges and pressure levels look very similar to me.

 

[helotaxi]

Very similar indeed

If you have access to something like Quickload, you'll find that you can play with the length of the barrel all you want and the peak pressure (which is what limits the powder charge in the first place on a max load) doesn't change even a little bit. Depending on the powder and cartridge, you'll also find that the percentage of a given powder charge that burns in the barrel varies more with pressure than with barrel length. All of these things further the case that trying to tailor the load by using a slower powder for a longer barrel is a waste of time because it simply doesn't work that way.