Ammunition And Headspace

For proper function, ammunition has to fit as well as any other part.

by RK Campbell

A gunsmith must realize that it isn’t always the operating mechanism of the firearm that creates trouble. Abuse is common and so are poor ammunition choices. Lubrication is important and poorly chosen accessories take their toll. Sometimes the design itself is less than ideal.

As an example, I recently worked with a lightweight frame .357 Magnum revolver. These handguns have six shot ancestors chambered for the mild .32 Smith and Wesson Long cartridge. The frame was deepened on the old I frame guns and the J frame was born as a five shot .38 Special revolver. As many of you know, airweight (aluminum frame) .38 Special revolvers can take a beating in the small parts with +P ammunition. When the same basic gun is chambered for the .357 Magnum anything can happen.

This particular revolver would not open when the cylinder latch was pressed. I wriggled the cylinder and it would not release. I tried the old trick of turning the cylinder in the opposite direction of normal rotation in order to tighten the ejector rod and nothing happened. Finally, I took a thin pick and was able to press the barrel underlug latch forward to release the ejector rod. The ejector rod looked as if it were beat up and the barrel lug latch was actually jammed into the peened section and would not allow the ejector rod to release. I can only surmise that the heavy recoil of the .357 Magnum cartridge transferred momentum and the result was a wedged part. In the end the revolver was opened and lubricated and the problem did not repeat itself after the offending part was dressed up. The revolver had been brought into the shop in a loaded condition. Having to fire the five loaded rounds out of the cylinder to safely proceed was an eye opener. The piece kicked like an overweight mule and the blast and noise, even with hearing protection, was tremendous.

Before proceeding with ammunition issues we need to discuss the usual run of cartridge malfunctions and how to differentiate between the types. The proper language can be important when dealing with the customer and solving their problems.

Read more in our August 2014 issue. Back issues are available.

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