Stop deforming bullets! Having cartridges straight and inline is critical for accuracy. Gunsmith work and customer education to ensure this happens is vital.

by Joe Carlos

We’re going to be talking about sending bullets straight into the back of the barrel in this article and how doing so contributes to tight groups. Good bolt-gun builders seem to have understood the importance of this before we gas gunners. If gunsmiths and shooters whose passion is the Stoner platform hope to rival bolt-gun performance, we need to take a few pages from their book. In doing so, both the gunsmith and the shooter share responsibilities.

What happens when a bullet hits the back of a barrel off center? It’s easy to envision the front end of the bullet being deformed and how that will degrade accuracy, however, some might ignore the also-important bullet base. If the front of the bullet is at an angle, the base will be tilted proportionally. That tilt will remain with the bullet as it spins down the bore. Where that tilt becomes critical is in the split second the bullet exits the muzzle when one side of the bullet is outside of the bore while the opposite side is still in. This will allow gas pressure to escape, causing the bullet to be pushed to the side. This is similar to a damaged crown allowing gas on one side of the bore to escape prematurely and push the bullet off course. In another lifetime, nearly a half century ago, I was a competition pistol shooter and hand cast some of my lead bullets. I remember other bullet casters who greatly valued a nice flat and straight base. I didn’t fully understand the emphasis on this at the time. Now I do. Here’s what is important.

Read more in the December 2018 issue.

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