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Advisory Panel
Originally Posted by
old tanker
as Brit Plumber has surmised
Really...just him? Check post #2.
Originally Posted by
old tanker
God knows why, a shim added by somebody.
Go back and re-read from the start and you'll see why it was added. Those are the ones you can buy in sets from Brownells and others...for tightening a loose Mod 10 S&W for instance...
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04-18-2017 09:53 PM
# ADS
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Legacy Member
It looks like someone has refinished the main parts but left things like screw heads in black sunc. The firing pin has been replaced as the locking rivet/pin isn't original and has been filed flush. The cylinder may have the original finish, it's hard to be sure but I do see over spray on the face of the recoil shield so it has had some paint applied at some time. Does the cylinder, frame and barrel have matching serial numbers or are there marks where one or the other may have been removed?
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Thank You to Brit plumber For This Useful Post:
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But, back to the problem.......... Get rid of the shim. It should not be there. End float of the cylinder is controlled by the cylinder stop cam acting in the groove in the extractor guide*. You test the cylinder/barrel face gap by feeler gauges holding the cylinder forwards.
* the extractor guide is the central axis of the cylinder that the extractor slides in. They do move slightly but I won't complicate things more.......
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Thank You to Peter Laidler For This Useful Post:
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Advisory Panel
Pictures are worth a thousand words. The description in post 5 leaves me a bit befuddled. It looks pretty honest to me and has certainly been fired since refinishing. Remove the washer and drive on forward.
---------- Post added at 08:22 AM ---------- Previous post was at 08:20 AM ----------
By the way: when I work on firearms, does that mean they're "dicked with"?
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Thank You to Brian Dick For This Useful Post:
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Legacy Member
The barrel, frame and cylinder are all stamped with the number Q2179. The problem with the revolver did not manifest itself until I went out to shoot it. The heads of the cartridges were so tight against the recoil shield the cylinder would not advance when you tried to pull the trigger. I started troubleshooting by measuring the space between the shield and the back of the cylinder with the cylinder held forward and the thickness of the rim of the cartridge. With the brass measuring .056 and the space measuring .049 the reason the drag was plain, the question was why, what should be and how is it supposed to get there started the search.
When the shim was discovered, the questions multiplied!! Is this supposed to be here? Is this how the fore and aft float is controlled? This one seems too thick, do they come in sizes? That quest lead here.
With the shim out, the cylinder will just rub enough to remove a chalk mark on the edge of 2 chambers, so that clearance is minimal. The clearance at the back of the cylinder is generous, it will pass a .070 gauge. I suppose if the firing pin is long enough it should go bang. That was suggested upthread, and shall be the next step.
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Legacy Member
The gap between cylinder and shield should be 0.060" - 0.066".
I have put together 1930 Enfield with renumbered barrel and cylinder with s 0.082" gap which I've had to retire.
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What you are describing in thread 15 is wear in the cylinder stop cam and/or the wear in the corresponding groove in the extractor guide. If it were my revolver and I didn't have access to those parts I'd just remove the shim, take it to the range and shoot it. It ain't going to let you down. You ought to invest in a little book by Mark Stamps. It's not a technical book as such but very good all the same.
Incidentally, the technical spec for the UK Military simply states that the .070" gauge must not pass between the recoil plate and the rear of the cylinder when the pistol is in the rebound position. While not arguing the point with Baal (thread 16) it doesn't specify a minimum spec. Just the one GAUGE, Slip .070"
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Thank You to Peter Laidler For This Useful Post:
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Legacy Member
...I'd just remove the shim, take it to the range and shoot it. ...
Took your (and browningautorifle's) advice, removed the shim, reassembled the revolver and test fired it after work today. Three cylinders full, no malfunctions. The results at 25 yards show that it is quite good enough for government work.
Cursed mightily whoever installed the shim, all his ancestors and all their progeny. They went to a lot of trouble making the damn thing as the dimensions do not duplicate anything Brownell's stocks. It had me confused for certain.
Once everyone here made it clear that the shim was bogus, I could see exactly, as you said, how the stop cam and the groove in the cylinder control the cylinder's position. If I stumble on to a new cylinder stop cam, I might try it to see. I shall look for Stamp's book, as you recommend.
Thanks to all here for all the advice and in helping me understand how this revolver was supposed to have been put together.
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Legacy Member
While not arguing the point with Baal (thread 16) it doesn't specify a minimum spec. Just the one GAUGE, Slip .070"
Those numbers are from Stamp's book.
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Thank You to Baal For This Useful Post:
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You're dead right Baal! I suspect that they have been superseded now by the EMER's from 1947 to '70 for one gauge.
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