how crucial is cylinder movement?


November 4, 2011, 07:45 PM
i've settled on a new 3 inch gp100. problem is, i can't find one anywhere locally and will have to have one shipped to my ffl.

i'm new to revolvers and have read the sticky about picking out a good specimen. in my travels, i have checked many a wheel gun for cylinder wiggle and end-shake. some, like a used colt trooper i've handled were absolutely rock solid, while others even new had a touch of end-shake and side to side wiggle. i've handled a couple 4" gp100s, but none came close to the "welded on" feel of that colt.

i'd really prefer to get my hands on the specimen before laying out the cash, but that doesn't seem possible. how do gp100s fare in the qc department, and is a little wiggle, if present, an issue?

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November 4, 2011, 07:55 PM
Within reason, No.

The old Colt design locked the cylinder in the locking notch with the bolt, while the hand pushed it the opposite direction against the bolt when the trigger was pulled. That resulted in the bank-vault lock-up you mentioned.
Until all the opposing forces wore out the hand & bolt timing.

Rugers, S&W's, and all other modern revolvers don't work that way.

A little end shake is necessary for proper function when the gun gets hot and things expand or lead up with fouling.

A little sideways rotation allows the bullet coming out of the chamber a little more leeway to align itself with the bore.

Or so some folks, including S&W say.

In short, it would have to be a very used & abused Ruger GP-100 for end-shake or lock-up to be a problem.

And if it is a problem, Ruger will fix it, probably free.


November 4, 2011, 08:02 PM
thanks, rc. this will be a NIB ruger. just wanted to make sure it wasn't best to get my hands on it first.

November 4, 2011, 08:28 PM
My .02 cents ? A couple years ago, I grabbed a new GP100 from a local shop, before I knew how to properly check a revolver out, but later found out I got lucky with the tightest GP100 I've ever personally handled. ( I was actually torn between a 4" and the 6" that I bought. Turned out later that my 6" was noticably tighter than the 4" I passed on).
Meanwhile,last year I traded into a M28 Highway Patrolman, and was discussing a re-finish with a very reputable local smith.This gun is an absolute joy to shoot,I fell in love with it immediately, but I was concerned with the cylinder play and especially, the end-shake, but the old guy asured my I was GTG.
Right after that, I purchased a set of feeler guages, and found my beloved new Smith had some huge amount of cylinder gap ( I forget, like twice the commonly accepted norm,I'm thinking 15 thousandths).
I still love the pistol, but bailed on the $100+ re-finish job.
Anyway, enough alcohol-fueled rambling...;).... pistols will vary, even new ones of the same model, and oddly, even old,loose ones can be great shooters.
This probably wasn't much help,at all,was it? :D

November 4, 2011, 08:34 PM
mil-dot, a good chuckle is always of some help;)

November 5, 2011, 11:30 AM
NIB go for it, if the only way to find one. Sometimes hard to get guns are just that. I too like to handle the guns but I have waited years to do that and finally had to go online.

November 5, 2011, 11:50 AM
I have quite a few revolvers including both Smiths and Rugers. They vary a good deal in fit and lock up. The two areas of lock up that are really crucial to operation are that the cylinder lock is a good enough fit to prevent the cylinder unlocking under heavy recoil. This is more of a problem in .44's.
The other is cylinder/forcing cone gap. Too tight and the gun will tie up from fouling after only a few shots. Too loose and you lose velocity and the gun spits crap all over.

Funny that MIL-DOT cites his M28 with massive cylinder/barrel gap. .015 sounds big but probably functions just fine and is definitely on the more reliable end of the spectrum. I say funny because I too have a M28 I am considering a refinish on but I have the opposite problem-my M28 has a barrel/cylinder gap of only .0015; that's 15 ten-thousandths. The gun gets tight after only a box of shells. It does, however, have the highest muzzle velocity of any 4" .357 I own.
MIL-DOT, if you had your gun Metalife or Cera Plated it might actually add some dimension. If the gun shoots well I say go for it!

Sorry for the ramble :) As to the original post, Ruger revolvers seem to have very consistent tolerances; particularly in later production variants. I wouldn't worry about buying a GP100 sight unseen; they are absolute tanks!

November 5, 2011, 12:22 PM
Mil Dot if that gap really bothers you send it to S&W they will turn the barrel and set it tighter. While its there you can have it refinished. I had a model 27 nickeled by S&W and they did an excellent job, so good the gentleman I sold it to didn't believe me when I told him it was a refinish until I showed him the invoice.

November 6, 2011, 08:13 AM
If you are going to get a 3" GP 100, I handled one of these and it was really nice

November 6, 2011, 09:43 AM
For todays designs it`s curcial it does move a bit to line up with the forcing cone !!

The days of the bank vaults such as rc mentioned are over !!!

When younger I had a Royal Blue Python that I shot the dickens out of & it went back to Colt at least 1-2 times a yr. for spittin.

Old Fuff
November 6, 2011, 10:11 AM
1. Like RC said, in a Ruger some rotational "wiggle" is both normal and necessary. If it was bank valult door solid (as it was in older Colt's) and the chamber wasn't absolutely concentric with the bore you'd have a problem and possibly shave lead on one side. The wiggle is so the chamber and bore can self-align as the bullet passes through.

2. The notch(s) in the cylinder, as well as the ball on the cylinder stop (that part of the stop that sticks up into the frame's cylinder window) both have a +/- tolerance. If you happen to get a revolver where the cylinder stop ball is on the plus side it is going to lock the cylinder with the least possible wiggle. This will feel good in the shop, and you can brag about it later, but if it results in too little wiggle to allow some chambers to be concentric when the cylinder is locked it may not be so wonderful. A little too much may be better then a little to little.

In any case they keep track of such things at the factory. Unless the revolver is spitting lead I wouldn't worry, and if you think it is a quick trip to the factory and back will cure it, no matter what's causing it.

November 6, 2011, 11:42 AM
thanks a bunch for all of your knowledge and insight. this helps me feel more confident and understand the workings much better. it should be here in a couple days...can't wait to get my hands on it. a badger boot grip and simply rugged sourdough pancake are in the works too. cheers! :)

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