I have preproductions of Colt Walkers and 1861 Army's. At a gun show I had two guys that were teenagers before WWII tell me that in their youth they would drill the flash holes larger in every other nipple. When the hammer fell on a drilled nipple it would rebound the hammer enough to rotate the cylinder and fall on a standard nipple. This was basically a two shot burst. In a 61 Army that was with a 25 grain FFg charge. In a Walker it takes a 40 to 45 grain FFg charge. I have no idea of the charge for a 36 caliber Navy model. Be sure to fill the loaded cylinder will lube over the bullet, so the fouling stays soft, and the second shot recoil is manageable.

Ivan