I just found this out and it confused me.
When the barrel on the revolver is measured, it's from the forcing cone to the muzzle. There you have the "speaking" length, the length that the bullet travel.
Now on the autoloader the chamber is included in the measurement and that threw me off. The chamber is not part of the "speaking" length of the bullet travel. I thought it was from the head space to the muzzle.
So while my Sigma 9mm have a 4" barrel I don't really have a 4" barrel, I have 3.25" of the "speaking" length of the barrel.
WTH?
When the barrel on the revolver is measured, it's from the forcing cone to the muzzle. There you have the "speaking" length, the length that the bullet travel.
Now on the autoloader the chamber is included in the measurement and that threw me off. The chamber is not part of the "speaking" length of the bullet travel. I thought it was from the head space to the muzzle.
So while my Sigma 9mm have a 4" barrel I don't really have a 4" barrel, I have 3.25" of the "speaking" length of the barrel.
WTH?