Single Ten Bisley Hammer, need some help.

[awilli]

I installed a Bisley grip frame on my Single 10 a few months ago and have used it with the original trigger and hammer due to problems finding a rimfire bisley hammer. I was finally able to order one from Ruger. It arrived today and I installed it. Now I am not able to cock the gun. I took it completely apart and re-assembled to make sure I did it correctly, and it still will not cock. I found that if I open the loading gate and pull the hammer back as far as it will go, then close the gate while holding the hammer back , it will cock, It seems to be a problem with the cylinder latch, but I do not know what is causing it. Any help & suggestions will be appreciated.

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[G2]

Pull out the cylinder.
Reinstall the basepin.
With your finger ,,, is the cylinder latch up and working?
Try and cock the gun, watch the cylinder latch operation.
Check loading gate/// cylinder latch operation.

From what you currently report it sounds like the the cylinder latch pin/spring is not on the bottom of the cylinder latch, it is off to the side. This miss alignment can happen during reAssembly.

My suggestion is to always check cocking operation with the gun fully assembled WITHOUT the cylinder in place, check the the pawl operation at this point also.

Welcome to the forum. :wink:

 

[awilli]

G2 thanks for the reply, however this was not the problem. I took the gun apart this afternoon and checked it. I also re-installed the original hammer while I had the gun apart and it worked perfectly. I then put the Bisley hammer back in and had the same problem of not being able to cock the gun. I can see the cylinder latch start to move when I try to pull the hammer back, but it will not drop into the frame unless the loading gate is opened. With the cylinder removed and the basepin installed the action works as it should with either hammer. The movement of the pawl & cylinder latch seem to be the same with both triggers. Again thanks for the response.

 

[G2]

Ok, these single tens, nines & sevens are fickle, this is a timing issue. I recently did the same change on my single seven and while it would cock it took some very fine adjustments to get it smooth. It was not timed even with the original hammer, had a very "chunky" cocking action.

Next I would swap out the hammer plunger and spring between the two hammers. I'm thinking the
plunger is a slightly different length.

My thinking is,,, The plunger is what contacts the cylinder latch and drop it in the cocking action.

When you crank the gate open it is helping to drop the cylinder latch, this indicates that the hammer plunger is the culprit.

Before swapping do some close comparisons of the relationships.

When one wants to slow down the timing to avoid the the cylinder drag mark on a new model, we build a longer plunger. I have done several of these and the length is critical to get the latch to drop when you want it and keep a smooth action.

Also check the depth of the plunger chambers, you might not have enough travel or some crud up in the the Bisley hammer. This is a good time to clean it good and deburr this area.

Bottom line is the plunger is not dropping the cylinder latch and the pawl is starting to push the cylinder, the cylinder can't move because the cylinder latch is engaged.
When you take the cylinder out it works just fine. One would think just shorten the pawl but I really think the problem is the hammer plunger length / engagement, and swapping these parts is the easy fix.

 

[awilli]

G2 thanks, I will try changing the plungers this afternoon.

 

[awilli]

I swapped plungers & springs between hammers today & still could not get the gun to function. I cleaned the plunger hole on the bisley hammer. I checked the depth of both holes & the one on the original hammer seems to be about .005 deeper & the plunger on the original hammer was .003 longer than the bisley. Any suggestions on what to do next will be welcome.

 

[G2]

TOTALLY STUMPED :roll:

My suggestion would be compare the hammers carefully, there has to be something slightly different with the Bisley Hammer, what I have no idea, I have done ~ 30 swaps, not 1 on a single ten. It has to be something with the shorter stroke of the single ten.

I would again study the movements of the pawl with the cylinder out comparing between the 2 hammers.

I would not install the gripframe, I would use the short screw and a small washer to hold the plunger spring in, and use my finger to be the cylinder latch spring.

Do all of this with the basepin installed. Not that it's required but it does keep the transfer bar working correctly and not hanging up on the firing pin.

There will be a real sense of accomplishment when you finally figure out what's up. :wink:

I'm surprised Hondo hasn't chimed in, I'll send him a PM.

 

[Hondo44]

G2 and awilli,

I don't usually visit the rimfire section of this forum. So thx G2 for the pm. Between the two of you, you have hit on all the probable causes.

awilli, as you posted in your first post, it seems to be a cyl lock issue. This is because of a slight variation in parts tolerances common in all guns.

Changing the plungers in the hammers is what I also would have tried first, but as you measuered, the differences in length are slight.

I believe your cyl lock bolt is on the tall side, and doesn't clear the cyl notch (as you suspected) by the time the pawl (which may also have a top tooth a bit tall) tries to rotate the cyl. You can test the theory; wrap some strips of masking tape around the front of the cyl lock. This will prevent it from rising too high. Make sure the cyl still locks in position with hammer down and gate closed. Or just go straight to #1 below. Now see if the hammer will cock.

If the gun functions properly you have two choices of resolution:

1. Knock the sharp edge and right front corner off the front of the top tooth of the pawl. You can do this with the pawl still in the gun. Take a stroke or two at a time and try the cylinder. This is the easiest and what I would do. The top tooth is not that critical to timing and hard to mess up.

2. Dress down the top surface of the cyl latch maintaining the angle and round shape. The advantage of this solution is that if you take too much off, you can fix it by dressing down the 'shelf' where you put the test tape.

Good luck, you'll get it, these simple adjustments can cause great frustration, but minor issues.

P.S. MY SHORTCUT FOR REMOVING JUST HAMMER and/or PAWL:

Recognize, you do not need to hassle with the PESKY LOADING GATE SPRING, pull the trigger pin, OR trigger/transfer bar JUST to remove the hammer and pawl. Once you remove the grip frame, the hammer pin is the only other part you need to remove. After that, just pull the hammer back and all the way down, then depress the hammer plunger in the base of the hammer with a small tipped screwdriver to clear the trigger extension where the transfer bar connects to it. Let the hammer & pawl fall out. Reinstall the hammer and pawl back in the same way they came out. Push the plunger in by pushing it against the trigger extension just like you did with the tip of the small screwdriver, and the hammer will slip by the trigger extension. Piece o' cake.

If either the trigger or hammer pin are snug fits, after they're removed the first time, it's the opportunity to polish them so they're slip fits to put back in and remove the next time.

 

[awilli]

OK! I now have a working bisley hammer in my single 10. Many thanks to G2 & Hondo44 for their help. I removed a little material from the pawl where Hondo said & now it works like a champ. I am glad this forum is here! Again, thanks guys.

 

[Hondo44]

Bravo!