[RM]

I have read several posts which refer to a handgun's "high bore axis" or "low bore axis." So what the heck is it, and why is it important?

[Sean Smith]

It is just a fancy way of saying how "high" the barrel of a handgun is relative to your grip on the gun. It matters because the higher the bore axis is, the more the gun will tend to twist in your grip when fired... basically, the further above the level of your grip the barrel is, the more leverage the recoil forces have against your hand. It doesn't increase or decrease the recoil forces, exactly, but rather how they are applied to your hand. A gun with a low bore axis will "shoot flatter," that is the recoil forces will be more straight back with less of a "flip."

The most obvious example of a high bore axis gun would be a typical double-action revolver. Glocks are generally considered to have a very low bore axis.

Personally, I think the importance of it is overrated compared to grip shape, overall ergonomics, mechanical design, and so forth.

[MrAcheson]

Like sean said, its the height of the barrel above your grip. So a high bore axis implies a longer torque arm for the recoil forces. Therefore recoil will create more torque and more muzzle rise.

The trick however is that the "more muzzle flip" analysis assumes everything else is equal. And it never is. More torque means nothing if you also have a higher moment of inertia, or different grip geometry between the two guns. XDs (and sigs) have relatively high bore axes. Glocks have low bore axes. Some Glock afficionadoes criticize the XD owners for this, but I have never heard a Sig or XD complain about their bore axis.

Shoot what you like and don't worry about bore axis.

[Island Beretta]

XD owners, what is your muzzle flip like?

[Leibster]

I have an XD9, and in side by side comparisons to my Glock 19, I don't really notice a difference. This may not be the best test, though, since 9mm isn't exactly known for it's brisk recoil.

--Leibster