Colt 22 New Frontier cylinder fitting

[what would you say]

i recently obtained a 22LR cylinder (in great condition) for a Colt New Frontier. The Colt had been hanging around the local gunshop a while since it only had the 22 mag cylinder I'm thinkin'.
The 22LR cylinder does fit into the revolver. It feels and sounds like the magnum cylinder that came with the gun when I go through the 4 clicks. It rotates nice and locks up when hammer cocked.
Q. Should I be concerned that there is more space between the cylinder and the barrel/forcing cone comparing it to the magnum cylinder? In other words, am I "aint done yet" or would it still be safe to shoot it?
I don't have the tools to make an exact measurement on the gap at the moment. I can just see that it is slightly more of a gap. I don't know if this affects safety and/or accuracy and what to do to adjust it if needed.

[Walter Rego]

You should do several things before shooting it: Buy a set of blade type feeler gauges, which are available at most any auto parts stores for just a few dollars. First, check the endshake. With the revolver uncocked can you slide the cylinder back and forth more than a couple thousandths of an inch ? Look at the gap between the bearing surface of the ring on the front of the cylinder and the matching boss on the frame. You want that to be just a hair to allow for expansion as the gun is fired and heats up. If there is too much slop you are screwed, as you don't want the cylinder battering the frame when it is fired. You can buy endshake washers to take up the slack but they are a pain as they fall off when you remove the cylinder for cleaning and you might have way too much B/C gap when they are installed to move the cylinder rearward. Then check the barrel/cylinder gap and headspace measurements. Tilt the gun barrel down, and push the cylinder foward. The measurement betweem the firing pin bushing suface and rear of cylinder should be .043-.048. The barrel/cylinder gap should be .006" + or - .003. Compare that to the .22 WMR measurements, they both should fall within that range. If the gun passes these tests you need to check the timing and I doubt that you have expensive range rods. So what I would do is shoot it, wearing eye protection and probably long heavy sleeves as well, anc check for lead spitting. Don't let anyone stand to the side while you are doing this. Pull the cylinder and look for obvious signs that lead was shaved around the forcing cone and barrel face. If not, you are probably good. I'm sure others that are more knowledgable will correct any mistakes I have made. I have fitted a couple of Ruger SA cylinders and it's about the same process. But first make sure that you don't have a lot of endshake, because if you do the chances of it being made to work right are slim. Find another cylinder that is too long and remove just a thousandth at a time from the front bearing surface of the cylinder until it roates without binding.

[what would you say]

Thank you very much for that info. I could not get the cylinder pin to seat fully until i took a very small amount off of the front bearing surface of the cylinder. basically that was the only difference I could visually see between the two cylinders was that that bearing surface was thicker on the new 22LR than on the fitted magnum cylinder. about 3 minutes with a tiny jewelers type flat file and the cylinder pin went in. I will check the endshake next. thanks again.

[what would you say]

Just to make sure a simple mind like mine has the basic idea of what's going on.. If there is too much end shake, then its a no-go because no way to add metal back to the front of the cylinder bearing surface. looking at the cylinder, I deduced that this was the only surface that could be adjusted by removing metal until the gaps on the front and back of the cylinder are right. I don't think end shake is a problem since the cylinder was basically scrubbing the firing pin end of the cylinder until I took some off the front. I think now the question is ..is how much to take off to get the gap right between the front of the cylinder and the forcing cone and make sure the end shake stays in specifications. I will follow your procedure on this, and I think it will work.

[Walter Rego]

Don't do anything until you check the barrel/cylinder gap with a feeler gauge ! If the cylinder has minimum endshake and turns without binding that is a good thing. If the gap is .006" + or - .003" (between .003" and .009") it is within industry accepted tolerances. If the gap is so tight as for the rear face of the barrel to rub on the cylinder you have trouble, and if it is so loose (like over .010") you will have velocity loss and possibly lead spitting. Then, a gunsmith could set back the barrel to correct those specs but you would likely have a problem with the other cylinder. And be spending a lot of money to fix it. I have several dual cylinder guns from Colt and Ruger and none of them have the same B/C gap for both cylinders but all are within a couple thousandths of each other and within accepted ranges. I think you'll be OK but go spend a few bucks on a gauge and see what you've got.

[what would you say]

thank you for all this great info. i had to take a few swipes with file off the front bearing surface of the cylinder to get it right. I felt like it was too tight to allow for heating and b/c gap was upper end of tolerance. b/c gap is now .006 on the new LR and it was less than .005 on the old mag cylinder. i'd say .004 (my gauges i had only go down to .005) and the rear cylinder gap is same on both +/- .001 at about .007 So the proof is in the puddin' as they say got to get it test fired. being as i am typing this holding the 1 yr old cowboy ..... it wont be today. thanks again. i feel so much better about shooting it knowing the tolerances are right. will follow-up with how that goes, following those precautions you mentioned.

[what would you say]

success story. shot fine. accuracy excellent. Thanks Walter.