A friend of mine has a 9mm cylinder in the red bag that looks to be unfired. How can you tell if it is an Old Model or New Model cylinder? I believe it miked at 1.835" but I can verify tonight.
Correct, it probably won't drop in and will need fitting. The over all length of the old model cylinders can be the same as new models, but the star notches on the back tend to stick out further and the gas ring in front is shorter. In other words, the cyl body can be positioned a few thousandths further forward.
That drawing is not from me but from H. W. Ross, 'FLATTOPS & SUPER BLACKHAWKS". This is the author that the Ross Flattops were named after. That being said I think it would make a good sticky
Just a short note, those drawings in Ross' book were done by our friend Roland Kirsch, formerly of the Akron,Oh area, may Roland rest in peace, one of the very early RCA members by the way.......... :wink: