I recently purchased an H&R .22 LR revolver w/a 6" barrel still in the original box it came in. I was told that only 9 rounds has ever been shot through it. My grandfather inlaw is a self proclamed gun expert estimates it is between 25to 30 years old. But anyway on my gun to open the cylinder the base pin is spring loaded, you just pull it and swing the cylinder open, then you push the base pin towards the cylinder to eject the spent shells. Mine is a Model 929 it is stamped on the left side of the barrel along with .22 LR and Made in the USA. Have you removed the hand grips to see if there are any markings on that part of the frame? I have absolutly no complaints on how it shoots, dependable and acurate. Get back with me, I am curious about your gun.