Extra Clyinder for new model 357 mag

Help Support Ruger Forum:


Mar 5, 2009
Little input please. I bought an extra 9mm cylinder from a friend for my 357 new model blackhawk. When installed it is locking up when I try to turn the cylinder. Here is the question... Do I mill the front of the cylinder where it is hitting the forcing cone or do I need to take it off the rear at the indexing lug. and if it is hitting how much do I need to take off...


Feb 22, 2007
I'm no expert but it sounds to me like you might need a little shim at the front of the cylinder to set the b/c (barrel/cylinder) gap. You will also want to check the cylinder end-shake and cartridge head-spacing. ...And after that you want to make sure that the cylinder charge holes and bore are aligned ...and after that, check and make sure the function and lock-up are correct. In other words you need to have the cylinder fitted to the gun. I would suggest a gunsmith. :D

Oct 24, 2007
Is it locking up when you try to turn it manually with the gate open, or when the gate is closed and you are trying to cock the gun?

Can you tell where it"s "hitting"?
Dec 11, 2002
yes, if the cylinder can "drop in", the front end ( boss/stud/gas ring) should be riding on the inside surface of the cylinder frame;it should be about touching, little or no gap.....the cylinder 'face' ( front) should be clear of the rear of the barrel ( breach) and there should be a "gap" of approx. .004-.008", NOT rubbing, nor touching in this area........of course the "rear" ( ratchets) should be riding against the inside of the recoil shield, a small gap...this gap in front as well as the rear, is your "end play"...we've seen them touching, seen them "gapped"...not sure off the top of my head what the "end play" specs are, but, the cylinder should turn, freely, no rubbing, and very little "play", front to back...if the wrong vintage cylinder, the barrel will be against the cylinder face or vice versa, a large gap on the 'gas ring'...when forward, the cylinder will rub touch or lock up against the rear of the barrel...wrong....BUT as said above, can be "shimmed" and corrected, made to work ...bottom line , it most likely will NOT just "drop in and work....." must be "fitted", then checked for alignment , (timing & lockup...) on ALL 6 chambers...........
and yes, at times they WILL just "drop in and work",but Uncle Murphy was an 'optimist'. :roll: