Mus408 said:
Most DA revolvers have a bit of spring tension holding the cylinder at the forward most position.
When the revolver is fired is the true gap with cylinder forward or will physics be pushing cylinder backwards?
*****
Two issues at work: 1) endshake, and 2) barrel/cylinder gap.
If there is zero endshake, gap stays constant at discharge. If endshake is present, it can be measured with feeler gauges.
Endshake and discharge
At hammer fall, firing pin strikes primer. Cylinder moves forward. Primer ignitions thrusts primer pocket (case) forward, while primer blows back. Power ignition starts bullet forward, cartridge case rearward. Expanding gas pries cylinder gap. Venting gas and bullet recoil thrust cylinder rearward, re-seating primer.
A cylinder with severe endshake may bounce under recoil like a slide hammer. Felt recoil does not begin until the bullet is well downrange.
Endshake may not hurt accuracy, but it doesn't help. The slide-hammer effect may peen standing breech and cylinder ratchet.
Barrel/cylinder gap by itself has no----or nearly no----negative effect on accuracy. Barrel/cylinder gap hurts velocity.
David Bradshaw