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Your post made me curious. Found this discussion on a different site, from some time ago.
 

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Discussion Starter · #3 ·
Your post made me curious. Found this discussion on a different site, from some time ago.
Thanks RBD,
great link. I feel a little better about my drag line now. Yesterday I gave the revolver a good hard look and realized the cylinder latch wasn't dropping below the frame when the loading gate was closed. Which means after the k
last tear down and cleaning I assembled it wrong. Stupid mistake! Good news is the drag mark buffed out and the slight one is returning.
I really appreciate your reply and the very interest link.
Thans,
TacoFrank
 

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All New Model Ruger SAs are subject to a cylinder drag line .... the more you use it, the deeper the drag line. Why? All New Models to include Single-Sixes, Blackhawks, Super Blackhawks, Vaqueros and New Vaqueros share the same cylinder latch and hammer design. Here's what happens: At rest, the cylinder is latched and won't rotate. When you start cocking the hammer the hammer plunger contacts the cylinder latch and pulls it down, releasing it so the cylinder can rotate. The pawl starts to rotate the cylinder and just about 10 degrees into rotation, the hammer plunger cams off the cylinder latch. This allows the latch to pop up under spring tension and contact the cylinder. As the hammer and pawl continue to rotate the cylinder, the cylinder latch will rub on the surface between lock notches and create a drag line.

I designed a fix for this condition but with blued guns, you need to do the modification before a drag line is created. Stainless guns are more forgiving because you can use a 3-M pad to buff out the drag line and make it look factory fresh.

The modification involves a making longer hammer plunger out of a 3/32" drill bit shank. This holds the cylinder latch longer into the rotation cycle so he cylinder latch will release just as it starts into the leade of the cylinder's lock notch.

Here's a hammer with a factory plunger on the left and hammer with a modified extended plunger on the right and a graphic of the plunger with the measurements:


 

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Discussion Starter · #6 ·
Hi Lowegan,
Thanks for the tip. Looks like a fix an average basement gunsmith could tackle. I would have never thought of the cure. the pin holding the plunger in on mine fell out and amazingly I found both pin and plunger. The spring stayed in. What luck! I had a hell of a tine reinstalling hammer and trigger assemblies or I would make one now. After all the frustration getting it back together Ill give in a rest. The videos on YouTube all made it look simple. Tried several and a combination of the all and lucked out. Don't know if I am clever enough to repete the pro cess. Lol !
Thank you for your reply and the cure.
TacoFrank
 

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Sr40ken, Some of us like to keep our guns looking like new. Here my Single-Six convertible, made in 1979. It's had the piss shot out of it yet it looks like new. I buffed both cylinders with a 3-M scotch-brite pad then did the hammer plunger trick so it will never have a turn line.

 
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When you tune the plunger to the proper length, there's no downside. If it is too long, it can bend or break when cocking the hammer. Here's where a few thousandths can make a difference. The plunger length could be adjusted at the factory but it takes time so it's much faster to assemble a SA with a short plunger that requires no adjustment.
 

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Discussion Starter · #11 ·
Or don't worry about it.
Or don't worry about it.
Howdy Sr40ken,
Not worrying about is probably good idea. My main concern was that it was that the timing had changed. This gun has seen many SASS shoots over the last 18 years.
Thanks for your reply.
All New Model Ruger SAs are subject to a cylinder drag line .... the more you use it, the deeper the drag line. Why? All New Models to include Single-Sixes, Blackhawks, Super Blackhawks, Vaqueros and New Vaqueros share the same cylinder latch and hammer design. Here's what happens: At rest, the cylinder is latched and won't rotate. When you start cocking the hammer the hammer plunger contacts the cylinder latch and pulls it down, releasing it so the cylinder can rotate. The pawl starts to rotate the cylinder and just about 10 degrees into rotation, the hammer plunger cams off the cylinder latch. This allows the latch to pop up under spring tension and contact the cylinder. As the hammer and pawl continue to rotate the cylinder, the cylinder latch will rub on the surface between lock notches and create a drag line.

I designed a fix for this condition but with blued guns, you need to do the modification before a drag line is created. Stainless guns are more forgiving because you can use a 3-M pad to buff out the drag line and make it look factory fresh.

The modification involves a making longer hammer plunger out of a 3/32" drill bit shank. This holds the cylinder latch longer into the rotation cycle so he cylinder latch will release just as it starts into the leade of the cylinder's lock notch.

Here's a hammer with a factory plunger on the left and hammer with a modified extended plunger on the right and a graphic of the plunger with the measurements:


Dumb question but I ask anyway. How critical are the.28" and the .1" measuremrnts? Is this something that can be done made by an amature with a dremel?
Thanks in advance.
TF
 

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Discussion Starter · #12 ·
Sr40ken, Some of us like to keep our guns looking like new. Here my Single-Six convertible, made in 1979. It's had the piss shot out of it yet it looks like new. I buffed both cylinders with a 3-M scotch-brite pad then did the hammer plunger trick so it will never have a turn line.

Looks new a brand new revolver! Awesome!
 

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TacoFank, If you are really skilled with a Dremel tool, you can freehand an extended plunger. The measurements are fairly precision. I made a special jig for my mini-lathe where I use the chuck as a pin vice then clamp the flex head of my Dremel in the X-Y axis head. The plungers come out dead on. Here's a picture of my setup:

 
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Discussion Starter · #14 ·
TacoFank, If you are really skilled with a Dremel tool, you can freehand an extended plunger. The measurements are fairly precision. I made a special jig for my mini-lathe where I use the chuck as a pin vice then clamp the flex head of my Dremel in the X-Y axis head. The plungers come out dead on. Here's a picture of my setup:

Very cool! My son in law is a pretty good amature machinist, I mightjust ask him to make one for me. Do you mind if I send him your drawing?
 

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Not a problem. No patent, I'm retired, and I got my money's worth out of the idea. I have made several hundred hammer plungers over the years. BTW, a good source of 3/32" drill bits is Harbor Freight. They sell a package of 6 for about the same price as one bit at a hardware store. The shanks are about the perfect hardness for a plunger.
 

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Having never removed a plunger from the hammer and now contemplating doing so, another couple of questions come to mind. The pin in the side of the hammer appears to retain the plunger. Is that correct? Does the factory plunger move up and down? Will it move up and down more with the longer (.28”) pocket?
 

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RBD, Yes, the small cross pin is what secures the plunger in the hammer's plunger hole. Normally this pin will just push out from either side .... no hammer or punch required. When the cross pin is removed, the plunger spring may launch the plunger so be sure to push the plunger in while removing the cross pin then ease the plunger out. No need to remove the plunger spring unless you want to clean it. I use a paper clip with a small hook bent in the end to pull the spring out.

The factory plunger moves in and out of the hammer's plunger hole. It works like this: When the hammer is being cocked, the plunger is fully extended so it can push the end of the cylinder latch up. The cylinder latch operates like a seesaw .... when the rear is pushed up, the front is pulled down to release the cylinder so it can rotate. When the gun is fired and the hammer thrusts forward, the hammer plunger strikes the cylinder latch arm and forces the plunger to retract in its hole until it cams off the cylinder latch. If the plunger doesn't retract, the hammer will stall and the gun won't fire. You can feel the plunger retracting and hear/feel it snap off the cylinder latch when you ease the hammer down slowly.

The reason why the notch in the plunger is wider is ..... the cross pin limits plunger travel so because the new plunger is longer, it must be able to go into the plunger hole deeper until the plunger cams off the cylinder latch.

The reason why the plunger is longer is: it holds the cylinder latch longer (more rotation) so the latch will pop up after the cylinder has rotated to the beginning of the tapered leade, located in front of each lock notch.
 
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RBD, You're welcome and I hope you can make a new plunger.
 

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Discussion Starter · #20 ·
Not a problem. No patent, I'm retired, and I got my money's worth out of the idea. I have made several hundred hammer plungers over the years. BTW, a good source of 3/32" drill bits is Harbor Freight. They sell a package of 6 for about the same price as one bit at a hardware store. The shanks are about the perfect hardness for a plunger.
Thank you very much for the help, drawing, and harbor Freight tip, You're the man!
TF
 
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