Hi nc native. To answer your question, no, thumb cocking the hammer on the Savage RFA revolver simply places the hammer on half or full cock. The cylinder does not rotate/index unless the cocking ring is pulled as a lift or lifting toggle/lever has to act to rotate the cylinder. The cocking mechanism draws the cylinder back away from the barrel breech, rotates the cylinder, cocks the hammer and by releasing the cocking ring allows the cylinder to move forward creating a gas seal between the barrel and each individual cylinder chamber.
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