Forums.NitroExpress.com

Pressure is the wrong consideration. It is back thrust and to some extent, recoil that stress the action. It comes as a surprise to most people to find out that a 12 gauge shot shell puts as much stress on the action as many rifle catridges, if not most.

The whole bit of "double rifles can't handle high pressures" nonsense got started during the transistion from black powder to smokeless. The new smokeless loads ran higher pressures. They hadn't perfected the brass and there were a few cases of sticky extraction due to less than perfect brass, occasionally aggravated by pitted chambers. The double does not have the mechanical advantage on extraction that a bolt action has. The first approach to curing this problem was the simple expedient of keeping pressures down. Over time the brass was improved.

There is an additional factor in that there is simply no reason to run high pressures in a double as the cartridge length is not limited by the action as it is in a bolt action.

So, given no need for high pressures and a desire for reliable extraction, cartridges designed for double rifles generally run low pressures. As far as the strength of the action is concerned, the modern double as an action type will handle just as much pressure as a bolt action rifle. With today's metallurgy, both types are ultimately limited by the limits of the brass which dictates that working pressures be limited to 65,000 psi. If grossly overloaded, a double will typically blow out the barrel, just like a bolt action.

The stress on the action is in part due to the cartridge back thrust and partly the tendency of the barrels to whip up and down under recoil forces.

Bottom line? As noted above, cleanliness and proper lubrication. Don't slam it open and shut.

Unless they are cheap junk, most doubles go off face due to abuse of one sort or another.

Post Extras