With 147 views, I figure it's time to go into detail.
Look into a revolver chamber. That small constriction at the front end is the chamber throat. The throat is sized very closely to bullet nominal diameter, and usually a couple tenths under. (.3568 in a .38/.357 revolver as an example.)
Drop an unfired bullet into a chamber and it sticks...and it requires a bit of force to push it through. If you use a lead bullet, it takes quite a bit of force, lead bullets usually being a thousandth over nominal. (.358 for a .38/357 revolver.)
The bullet is guided in a straight line by the throat from the instant it moves.
Now, drop that same bullet into the barrel. The point that it stops is where the rifling begins. Take note of how far the bullet protrudes from the rear of the barrel. Swing the cylinder toward battery and you can see how much of the bullet is still in the chamber throat and we can start to understand that before the base of the bullet even gets close to the gap, the bullet is well into the barrel. With some combinations...such as a K-Frame Smith & Wesson and 158 grain bullet...the bullet is into the barrel before the base clears the case mouth.
Any slight misalignment between chamber and barrel is corrected by the rotational play in the cylinder and the taper of the forcing cone. That rotational play appears to be around .010 inch in most new revolvers, but I haven't actually measured it.
All this assumes that the gun is in proper working order and the chamber throats aren't burned out or badly sized, which I understand
has been the case with some few Ruger LCRs...which is odd since Ruger is known for undersized throats. (.356 in 38/357 revolvers.)
And there you have it. A misconception shot fulla holes...pun intended.
Look into a revolver chamber. That small constriction at the front end is the chamber throat. The throat is sized very closely to bullet nominal diameter, and usually a couple tenths under. (.3568 in a .38/.357 revolver as an example.)
Drop an unfired bullet into a chamber and it sticks...and it requires a bit of force to push it through. If you use a lead bullet, it takes quite a bit of force, lead bullets usually being a thousandth over nominal. (.358 for a .38/357 revolver.)
The bullet is guided in a straight line by the throat from the instant it moves.
Now, drop that same bullet into the barrel. The point that it stops is where the rifling begins. Take note of how far the bullet protrudes from the rear of the barrel. Swing the cylinder toward battery and you can see how much of the bullet is still in the chamber throat and we can start to understand that before the base of the bullet even gets close to the gap, the bullet is well into the barrel. With some combinations...such as a K-Frame Smith & Wesson and 158 grain bullet...the bullet is into the barrel before the base clears the case mouth.
Any slight misalignment between chamber and barrel is corrected by the rotational play in the cylinder and the taper of the forcing cone. That rotational play appears to be around .010 inch in most new revolvers, but I haven't actually measured it.
All this assumes that the gun is in proper working order and the chamber throats aren't burned out or badly sized, which I understand
has been the case with some few Ruger LCRs...which is odd since Ruger is known for undersized throats. (.356 in 38/357 revolvers.)
And there you have it. A misconception shot fulla holes...pun intended.
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