{"id":28892,"date":"2025-02-26T00:01:21","date_gmt":"2025-02-26T08:01:21","guid":{"rendered":"https:\/\/exhaustnotes.us\/blog\/?p=28892"},"modified":"2025-02-10T13:38:11","modified_gmt":"2025-02-10T21:38:11","slug":"the-wayback-machine-whole-lotta-shakin-going-on","status":"publish","type":"post","link":"https:\/\/exhaustnotes.us\/blog\/index.php\/2025\/02\/26\/the-wayback-machine-whole-lotta-shakin-going-on\/","title":{"rendered":"The Wayback Machine: Whole Lotta Shakin’ Going On"},"content":{"rendered":"
By Joe Berk<\/h6>\n

I took my Model 60 S&W apart to clean it and somewhere along the way I lost the shims I put in to reduce cylinder end shake.\u00a0 A quick email to good buddy Lance Shively and a set of shims later, and I’m back in business.\u00a0 That got me to thinking:\u00a0 I had written a blog on installing the shims several years ago and I thought it would be a good idea to run it again.<\/p>\n

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I love my S&W Model 60 and I shoot it a lot.\u00a0 It’s particularly cool after I had TJ (of TJ’s Custom Gunworks<\/a>) do an action job on it.\u00a0 Not content to leave well enough alone, I convinced myself that (after tracing the occasional double action misfire to not-fully-seated primers) that what I really needed was a lighter hammer spring (in addition to the lighter trigger spring I had already installed).\u00a0 Wolff Springs sells a lighter hammer spring kit, and I went for the lightest hammer spring I could get.<\/p>\n

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The Wolff Springs hammer spring kit. I went with the lightest spring.<\/figcaption><\/figure>\n

The lighter trigger spring affects single action trigger pull after you have already cocked the gun and it has nothing to do with the occasional double action misfiring I had experienced in the past.\u00a0 Double action trigger pull is affected by both the trigger spring and the hammer spring, but the hammer spring is a much beefier spring and it drives most of the resistance when firing\u00a0 double action.\u00a0 The hammer spring, if too light, can induce misfires.<\/p>\n

The Wolff hammer spring kit includes a standard strength spring (an 8 1\/2-pound spring), a heavier spring (a 9-pound spring), and a lighter spring (an 8-pound spring).\u00a0 \u00a0I wanted a lighter double action pull, so I used the 8-pound spring.\u00a0 The tradeoff is this puts less force on the hammer, which means it has lower velocity when it hits home, and that ups the likelihood of a misfire.<\/p>\n

The hammer spring is easy to change, and if necessary, I can go for either of the two heavier springs at the range.\u00a0 All it takes is a small screwdriver to remove the grips, and the same exotic custom tool used for disassembling the Rock Island Compact 1911 (a bent paper clip).\u00a0 The photos below show how this is done.<\/p>\n

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The Model 60’s hammer spring, with the hammer in the uncocked position.<\/figcaption><\/figure>\n
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The Model 60’s hammer spring, with the hammer cocked. Note that the hammer yoke (the rod running through the center of the hammer spring) has been pushed back, exposing a hole in the rod.<\/figcaption><\/figure>\n
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A high tech, German tool steel special assembly\/disassembly aid? Nah, it’s a bent paper clip and it works gang busters.<\/figcaption><\/figure>\n
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To remove the hammer spring yoke and the hammer spring, insert the paper clip into the yoke and gently release the hammer by pulling the trigger and lowering the hammer.<\/figcaption><\/figure>\n
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With the hammer dropped, the spring is captured in a compressed mode and the hammer spring and the yoke can be removed from the gun. Once this subassembly is removed, you can manually push the spring cap to further compress the spring, remove the paper clip, remove the spring cap and spring, and install the lighter hammer spring. Assembly is the reverse of disassembly.<\/figcaption><\/figure>\n

While installing the new hammer spring, I noticed that my normal gun cleaning routine just wasn’t cutting it on the Model 60.\u00a0 \u00a0 There was still a bit of lead in the barrel, and the powder residue was building up around the yoke.\u00a0 \u00a0I selected a bronze bristled toothbrush and went to work on the cylinder, the yoke, and the frame, and a bronze bore bush for the bore.\u00a0 When the remnants of gunfights past were gone (you know, my encounters with zombies<\/a>, as previously described), I spritzed the gun with the universal cleaner (WD40<\/a>) and then I wiped it down before applying gun oil<\/a>.<\/p>\n

That’s when I noticed that the barrel-to-cylinder gap was nonexistent.\u00a0 Zip.\u00a0 Nada.\u00a0 Zero.\u00a0 The front of the cylinder was touching the rear of the barrel.\u00a0 Uh oh.\u00a0 That’s no good.\u00a0 \u00a0There’s supposed to be a gap there (like you see in the photo below), because if there’s no gap the cylinder will drag on the barrel.\u00a0 That will degrade the double action trigger pull and, in a worst-case scenario, it can drive the revolver out of time (the chamber won’t be aligned with the barrel).\u00a0 The technical term for the fore-and-aft cylinder movement that assures a minimum clearance when the cylinder is fully forward is called end shake.\u00a0 There needs to be some, and there needs to be a gap. Ideally, that should be 0.004 to 0.008 inches.\u00a0 Any less, and powder and lead residue will bind the cylinder, any more and too much gas escapes (and velocity suffers).<\/p>\n

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The barrel-to-cylinder gap. This is about .004-inch with the cylinder pushed forward, and that’s the gap I want. This was after I installed the TriggerShims.com<\/a> cylinder shim.<\/figcaption><\/figure>\n

You measure the barrel-to-cylinder gap with a feeler gage, just like you would when setting the valves on a motorcycle.\u00a0 I’ve done that (as you know from reading this blog and any of the CSC shop manuals<\/a>), and I already had the feeler gages I needed.<\/p>\n

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My feeler gage. I’ve probably owned this tool for 40 years. It still works. I use it for adjusting valves on my Royal Enfield, too.<\/figcaption><\/figure>\n

After a bit of internet research, I learned that the way to address inadequate gap is by shimming the cylinder and its fit on the yoke.\u00a0 That’s when I first learned there’s a business that specializes in making shims for this exact purpose.\u00a0\u00a0In short order I was communicating with Lance Shively, who heads TriggerShims.com<\/a>.<\/p>\n

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The cylinder shims from TriggerShims.com<\/a>. They were well packaged and sent in a standard business envelope.<\/figcaption><\/figure>\n
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The cylinder shims out of the pack. I ordered the four-piece set because I had not worked with these before, I didn’t know what I would need, and they were inexpensive. They are color coded by size.<\/figcaption><\/figure>\n

Lance and his wife, Tammy, run a real Mom and Pop operation that manufactures gun specific shims for a living.\u00a0 Lance has an extensive background in small engine repair and tool and die making, and he and Tammy parlayed that into TriggerShims<\/a>, which has been doing well for more than 14 years now.\u00a0 Lance told me his primary concern is customer satisfaction, and I can tell you my perception in working with TriggerShims<\/a> is they have mastered it. I had the Model 60 custom end shake shims in three days, there was no postage charge, and the price was more than reasonable for custom gun parts.\u00a0 \u00a0Lance runs a Christian business, he believes in God and country, and he’s not bashful about letting people know that.\u00a0 \u00a0He and Tammy also sell select items from other vendors when he finds a company he likes and believes in, but that is a very select group.\u00a0 The two biggest ones are Wolff and Volquartsen.<\/p>\n

I received the shims I ordered from Lance in just a few days, and installation was trivially easy.\u00a0 I had to remove the yoke, disassemble the ejector rod from the extractor, install the shim I wanted to use (I went with a single .003-inch shim to give the clearance I wanted), and then reassemble everything.\u00a0 It only took a few minutes, and the only tricky part was remembering that the ejector rod had a left-hand thread.<\/p>\n

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This screw has to be removed to allow removal of the yoke and cylinder from the revolver. You don’t need to remove the revolver’s side plate.<\/figcaption><\/figure>\n
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With the yoke removed, you unscrew the ejector rod (the knurled piece you push on to eject empty brass from the cylinder) and everything comes apart. Hold on to the ejector rod as you unscrew it so parts won’t fly away, and remember that it is a left-hand thread.<\/figcaption><\/figure>\n
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The cylinder shim(s) fit beneath the extractor spring. They are pushed into the cylinder by the extractor spring as the cylinder and yoke subassembly are reassembled. The shim(s) position the cylinder further to the rear, increasing the barrel-to-cylinder gap.<\/figcaption><\/figure>\n

TriggerShims.com<\/a> manufactures over 100 firearm-specific shims with thicknesses from .002-inch to .007-inch, with some specialty items as thick as .010-inch\u00a0 and\u00a0 as thin as .0015-inch.\u00a0 Lance sends shims worldwide, with Australia and Canada being the biggest international customers (he also ships to more than 100 other countries).<\/p>\n

Lance and I had a good conversation, during which he told me he enjoyed exploring the ExhaustNotes site and our blog.\u00a0 One thing led to another, and TriggerShims.com<\/a> is our newest advertiser.\u00a0 You’ll see the TriggerShims.com<\/a> logo on the ExNotes blog and all ExNotes pages, and Lance asked if he could post links to some of our Tales of the Gun<\/a> stories on the TriggerShims.com<\/a> site.\u00a0 Hey, you bet, Lance, and welcome aboard.<\/p>\n

I had the Model 60 on the range yesterday morning, and it is a much smoother running revolver.<\/p>\n

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