Hmmmm...strange prob with my 1851 Lyman

[noahmercy]

I just purchased a secondhand Lyman 36 cal 1851. It appears to be unfired which agrees with what the previous (original) owner told me. It's also an older model, judging from the box, however I can't determine if it is an Uberti, Pietta, or "other".

The problem I'm encountering is throw-by on three consecutive chambers. It is the same three every time around. The hand comes up the same amount each time and there is a small amount of "overcamming" in the hammer which doesn't seem to have a negative impact on the other three chambers. (I've also noticed most other revolvers share this trait, so I doubt it's an issue.) I suspect the bolt is a little short due to the drag marks and slight battering of the notches, but agin, three chambers work fine.

Do I need to remove a little bit of the leading edge of the ratchet teeth opposite the three chambers which are throwing by?

I sure appreciate any and all advice, recommendations, and shared knowledge.

:thumbsup:

 

[mykeal]

I'm not familiar with the term "throw-by", so I'm not sure what's happening. Do you mean that the cylinder is over-rotating past the battery position on three cylinders? When the hammer is in full cock is the bolt fully engaged in the notch or has the cylinder rotated too far for it to engage the cylinder? If it's not engaged, is the cylinder free to rotate by hand? If so, can you reverse it enough to get the bolt to engage the notch?

It would seem that, with the problem (whatever it is) occuring in just 3 of 6 positions on the cylinder that the cylinder cam teeth are indeed the root cause. But I'll not propose taking any action before I see the problem.

 

[noahmercy]

How do, mykeal.

By "throw by" I do mean it is over-rotating. I can reverse it by hand slightly and have the bolt engage the cylinder notch and lock it up properly. The only cause that comes to my mind is that the teeth that index those three chambers are a little wide.

:thumbsup:

 

[mykeal]

Ok, three things:

Speed is often an issue. Does it happen regardless of how fast the hammer is pulled back?

The "anticipation notches" on three of the chambers may be a bit too shallow and the trigger/bolt spring is probably weak (older gun, unfired - spring sitting in one position for a long time); when the bolt drops in the "anticipation notch" it doesn't drop far enough to enter the full notch and the spring is too weak to force it down further. Are there any scratches/marks in the "anticipation notch" or any damage to the other side of the regular notch edge that would indicate bolt interference? Also, any marks on the bolt itself? The bolt should have one side beveled - is that the case, and if so is it marked?

The cam teeth on the cylinder may indeed be too large on three cylinders; I expect the issue is really machining burrs since the gun is essentially a new gun. If that's the case you should be able to feel them with your fingertip. They are easily removed with a small flat file. Go slowly and don't remove too much metal! Keep checking by comparison with the good cylinder teeth. This problem should also go away pretty quickly with normal wear.

Manufacturer's marks: are you familiar with the Uberti/Pietta/ASM stamps? Look for a U surrounded by what looks like the end of a muzzle, or the letters *** in a diamond, or the letters ASM. Check underneath the loading lever near where the barrel enters the frame. Also the right side of the frame above the front of the trigger guard.

 

[LEE3370]

While you are looking it over, look for DGG. That is for Armi San Paolo which is now Euroarms. You may have to remove the grips and look on the side of the grip strap. The stamping on the side of the grip strap is small.

 

[noahmercy]

Muchos gracias, mi amigos. :grin:

It does over-rotate regardless of how quickly I work the action. And the three "good" chambers don't advance nearly as far as the three I have issue with, so I'm gonna' have to do some light stoning on the teeth to reduce the amount of throw. (I'm painfully familiar with the concept of metal being hard to replace...)

:thumbsup:

 

[mykeal]

Muchos gracias, mi amigos. :grin:

It does over-rotate regardless of how quickly I work the action. And the three "good" chambers don't advance nearly as far as the three I have issue with, so I'm gonna' have to do some light stoning on the teeth to reduce the amount of throw. (I'm painfully familiar with the concept of metal being hard to replace...)

:thumbsup:

You got it. Good luck.