Cylinder fitting question

[tek4260]

I received another cylinder for my well worn OM Super today and fitted it to my revolver. The original cylinder measured 1.950" and had about .006 endplay. I installed a .005 gas ring shim but this set the b/c gap at around .009.

The new cylinder was 1.958 by my caliper, so I carefully stoned it back to 1.956 on a ceramic stone keeping it perfectly flat. It is a bear to install but once in, turns freely. I have 0 endplay, or at least not enough to feel or measure even when using a small screwdriver to pry a bit. The b/c gap is .005 which is wider than I'd like, but I can live with it. I also have a Belt Mountain pin installed that I had to polish down to install it thru the cylinder. I checked timing and barrel/cylinder alignment with my 44 range rod and everything is good.

Is there any problem with setting one up this tight?

 

[flatgate]

I see no problems EXCEPT when the cylinder gets warm and expands a wee bit. This may create some "binding" but, it may not. It depends on just how much room is really there.

Range Rod? From G. Bunker? Most other's contain enough slop that, IMHO, they are almost worthless.

How tight is your cylinder latch fit to the cylinder frame and the cylinder?
If tight then your cylinder may be locked in a misalignment situation that your range rod won't indicate.

I'm just thinking out loud here. I'd shoot it with some "mild" loads and see how it does!

JMHO,

flatgate

 

[tek4260]

I don't believe it is one of his range rods. It came as a set from my dealer. It is a set, 22, 38, 44, and 45. He got them when he bought out another store along with tons of parts. I haven't measured them, but I know that I had to clean my barrel to get it to slide down the bore and any oil will create a vacuum, so they are about as tight as they can be. The shoulder at the end is also square so it will not align the cylinder if it is out of line. I will have to post some pictures. When I cocked the revolver, I was gentle as I could be and it still lined up on all 6 cylinders.

As far as the latch, it is tight as well. Are there any other checks?

How does Ruger go about fitting them? I can understand legnth, but what about alignment? There isn't any real way to adjust it with their level of production is it? I feel it is within "factory tolerence" as far as timing.

I was playing around with my original base pin and drilled and tapped it like Belt Mountain. The revolver is tight enough that when I slightly tighten the set screw, I get binding. Oh well, the #5 sets in a recess so this is no issue.

 

[flatgate]

G.B.'s range rods come with a calibre specific bushing, a "fit" piece of brass, that the rod's head slides into only if the chamber aligns with the barrel, albeit without any movement or via a bit of "free play/float".

Ruger's solution to the alignment issue seems to be a bit of cylinder "float", i.e. slop, so the bullet can move the cylinder into alignment as it moves from the cylinder throat to the barrel's forcing cone.

Of course, the proper technique is to line bore the cylinder, while it's in it's cylinder frame, with a fixture that screws in the receiver's barrel threads.
A technique that is labor intensive, in my humble opinion.

flatgate

 

[tek4260]

So I could possibly measure the diameter of my range rod, then machine out a bushing to go in the cylinder. I know that on my 45's, the range rod fit perfectly in the throats, before they were reamed to .4525. I may have to visit my gunsmith friend and turn some of those bushing. OD is chamber diameter, ID is rod/bore diameter.

Thanks! I see some of those oversized cylinder stops in my future.

 

[Ale-8(1)]

A really neat feature of GB's range rods is that they are so arranged that you can not only detect cylinder/bore misalignment, but actually tell where in the circumference of the chamber mouth the misalignment is located.

I certainly hope it will be possible for him to resume production of these wonderful tools, but it looks doubtful.