S&W Revolver Detailed Disassembly, Deep Clean and Reassembly

[_CY_]

check to see if Model 18-3 is in time. accuracy and safety depends on cylinder being in correct position when hammer is dropped.

cock hammer back into locked position. cylinder properly in time is locked up.

cylinder stop is in center of picture

slowly pull trigger, cylinder stop will first drop, then raise up about mid point between slots on cylinder. as hand rotates cylinder, stop will dovetail into slot locking up cylinder.

if you can rotate cylinder with hammer fully cocked, then revolver is out of time. fixing requires ordering an oversized hand, requires custom fitting.

use a feeler gauge to check gap between cylinder and barrel.
call S&W for tolerances, which could be different for each model.

Model 18-3 measures .007in front gap (.008 feeler gauge was a forced fit), .006in for rear gap. side to side rotation at lockup ended up at .003in after new stop was installed.

Fin.... whew, what a long writeup!!!
and yes double action is smoother and cylinder lockup is tighter.

 

[_CY_]

removing an extra stubborn barrel pin without damage ... this requires a 5C collet set typically used by machinist.

clean threads with alcohol, then use only medium strength Blue Locktite

 

[_CY_]

Next up is to reduce trigger return spring weight. too much reduction is not good as this could effect follow up shot speed.

clipping coils off spring will reduce total travel length, causing problems.
correct method is to reduce diameter of spring material by setting a special fixture (nail & visegrip), then grind off. (or purchase a reduced weight spring)

easy does it... go slow ... a few thousands at a time

sand spring surface to remove rough edges ... reduces friction with spring holder

 

[_CY_]

let's focus on the top sear, which is pinned to hammer.
drive out pin using a steel punch. top sear gets large load during double action pull. so all sides of sear needs to be stoned. ark white rock bottom surface that mates to trigger's sear face.

 

[_CY_]

setting trigger return spring can be a challenge. here's a special tool that makes job easy.

make sure blade is thinner than spring holder slot

file notch with a quality file with square edges

simply insert tool, push spring pass pin then rotate home

 

[_CY_]

as revolver is fired, cylinder heats up and grows longer. if gap between barrel and cylinder is too tight, revolver will cycle fine cold. but jams after a few shots.

ammo can be very dirty, especially .22LR. take a brass brush and give underneath injector and top of cylinder a good scrub. make certain injector is able to seat completely into cylinder face.

even tiny amounts of debris under injector can reduce end gap and cause revolver to jam after a few shots.

check gap with feeler gauge after cleaning. gap opened up after cleaning

 

[_CY_]

It's now time to close this brief article out with a how to put the side plate back on.

Thanks for looking... Fin.

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by now if you've been following along... you will have taken off and put side plate back on several times. here's how to put on side plate the easy way.

note how safety rides inside groove on side plate

first slide safety to position below

align side plate's groove with safety, then slide upwards to home

after side plate lays down flat, wack with a soft sided tool

 

[John6185]

Very informative and helpful, thanks for posting!

 

[FrankNmac]

It only took almost seven years for this to get a comment! Now I am doubling that number. I did like the pictures and explanations of the process.

 

[APH Tactical]

Very nice post, and incredibly informative!
I don't know if this term had every been used before(hard to be "original" in 2017) but if not, then I'd like to take a moment and use this post to call this the first official...
"ZOMBIE THREAD" lol