[quote=craigd][quote=BrentD, Prof]
.....I still find it curious that proof pressures seem to be related only to gauge and chamber length. A gun made by the same shop, with 2.5" chambers cannot handle the service pressure of another from the same shop made with 2.75" chambers and identical lock-ups. Yet two guns made in different shops, much different in construction including locking lugs and barrel materials and thicknesses are proofed to the same pressures, if they have the same chambers.
I have never seen a good justification for this.
A 2 1/2" chambered gun might stand up to service pressures of the 2 3/4" shell, no rule says it can't. A 2 3/4" live pigeon gun will probably be heavier/stronger than a 2 3/4" game gun even though they are both proofed to the same standard.
I look at it as being somewhat comparable to metallic pistol cartridges and ratings of "standard", "+P" and "Magnum". Standard 38 Special loads are just fine in your typical pencil barrel S&W Model 10, "+P" ammo is better relegated to the stronger Model 19. Moving up to "Magnum" loads belong in the Model 27 as evidenced by the number of "K" frame guns that were shot loose with magnum ammo.
.38 Special = 2 1/2"
357 Magnum = 2 3/4"
357 Maximum = 3"
Just my thoughts on the subject, certainly others are more learned than me.
