Well, this is a challenge. I've never heard of primer erosion, but maybe we can go through the firing process and see if we can come up with something.
When the primer fires, the area surrounding the dimple made by the firing pin will be forced rearward toward the breechface by the force of the expanding gasses (recoil). This puts a strong force on the breechface area immediately surrounding the FP hole. If the edges of the hole are crisp and sharp, the vibration of repeated firings could cause the edges to chip off from metal fatigue. If you looked at a microscopic cross-secitonal view of the hole, you would not see the sharp edge that a drawing would imply, but a jagged one.
A simple analogy would be the drawing of a cliff with a straight drop, compared to the real thing. The drawing would show a horizontal line abruptly changing to a vertical line. The actual cliff, however, would not be so abrupt, but would have small dips, and peaks as it changes from the horizontal to the vertical.
The same idea applies to the FP hole, but on a microscopic scale. Just as you could stand a few feet from the edge of a cliff, and knock off pieces of the edge by repeated impacts on the ground where you are (you may need some help to do that, like a heavy pile driver), the repeated impacts of the primer against the breechface surrounding the FP hole can knock off small pieces of metal over time.
Should you be concerned? I know I wouldn't be as long as the performance of the gun doesn't change, and the brass isn't adversely affected. You didn't mention how much service the gun has had, but, unless there is something wrong with the temper of the slide, and other symptoms appear, such as cracks in the breechface, I don't see a cause for immediate concern.
I would just keep an eye on it, and go ahead and shoot it.
When the primer fires, the area surrounding the dimple made by the firing pin will be forced rearward toward the breechface by the force of the expanding gasses (recoil). This puts a strong force on the breechface area immediately surrounding the FP hole. If the edges of the hole are crisp and sharp, the vibration of repeated firings could cause the edges to chip off from metal fatigue. If you looked at a microscopic cross-secitonal view of the hole, you would not see the sharp edge that a drawing would imply, but a jagged one.
A simple analogy would be the drawing of a cliff with a straight drop, compared to the real thing. The drawing would show a horizontal line abruptly changing to a vertical line. The actual cliff, however, would not be so abrupt, but would have small dips, and peaks as it changes from the horizontal to the vertical.
The same idea applies to the FP hole, but on a microscopic scale. Just as you could stand a few feet from the edge of a cliff, and knock off pieces of the edge by repeated impacts on the ground where you are (you may need some help to do that, like a heavy pile driver), the repeated impacts of the primer against the breechface surrounding the FP hole can knock off small pieces of metal over time.
Should you be concerned? I know I wouldn't be as long as the performance of the gun doesn't change, and the brass isn't adversely affected. You didn't mention how much service the gun has had, but, unless there is something wrong with the temper of the slide, and other symptoms appear, such as cracks in the breechface, I don't see a cause for immediate concern.
I would just keep an eye on it, and go ahead and shoot it.
