Colt Bisley clone issue

M

mravery

New member
Hello all,

I recently purchased a Cimarron Bisley in 45 colt with the 7.5" barrel. I have a feeling that this was a Monday or 5PM Friday gun as I have had all kinds of issues with it. I have fixed most but not sure about this one, hence the post.

Using Snap Caps, the gun works flawlessly. Locks up tight and with the new Wolff trigger spring I get good 'snaps' with the trigger cocking. Problem is, when I fire it, the first 20 or so rounds work great, then cocking the trigger starts to stick a little and then I get FTF with the primer hits being way off center, even as far as the rim of the primer.

When I look at the cylinder, there are no drag marks between the lock grooves but what I did notice this last time are some very faint shiny spots on the far edge of the lock grooves. Almost like it is over advancing the cylinder.

Any ideas or thoughts?

Cheers
Mark
 
Agree.

I have had a revolver with too little spring pressure on the bolt so that it didn't hop up fast enough to get into the cylinder locking recess (notch) before the notch skipped past the bolt. However, the shiny spot may also be caused by the bolt not quite clearing the recess 100% by the time the hand (pawl) starts rotating the cylinder, in which case it's probably unrelated. Ont the other hand, it may also be the top edge of the bolt is rounded or it doesn't extend into the notch far enough so that it barely latches the cylinder, and when the gun starts to heat up you get just enough expansion so it starts to fail to latch. Lots of things to look at.

Are the off-center hits corresponding to over-rotation?
 
I would first see if it is a cleaning problem. Powder residue is getting into the base pin and bushing area and gumming up the cylinder so it doesn't turn easily. The hand is probably a bit short so the cyinder won't carry up if it is retarded by crud, so it won't lock up. This is most common with black powder, though some kinds of smokeless will do it also. I suggest:

1) you have the timing and carry-up problem corrected and
2) switch powders and/or change bullet lubricant.

There is also a possibility that the barrel-cylinder gap is too tight and the cylinder is binding on the barrel when it heats up. That would keep the cylinder from turning but would do so until the gun cools, something that is not mentioned.

Jim
 
I never thought of the heating up issue.

When I fire it cold (snap caps) couple of hundred times I have no issue.

I did not notate the position of the off center hits before I took them out of the chamber so I wont be able to check that until the next time.

I'm shooting only smokeless powder (Trail Boss) and the bullets are 200gn or 250gn lubed RNFP bullets from X-Treme. They shoot flawlessly in my other SAA.

Never thought about the cylinder gap, that would make the cylinder hard to rotate with the hand.

Could also take a look at the bolt, perhaps put some chalk on it and see where is it actually touching the cylinder.
 
Drag the thumb of your non-shooting hand on the cylinder while cock the hammer slowly. When the hammer is cocked, check to see whether the bolt is in the cylinder slot. Probably not.

Not very familiar with the exact model of colt revolver of yours. I assume it has colt's signature 2-stage hand, in which case the hand is a bit short.

Revolvers require hand fitting. The person who last did it likely didn't do a thorough job.

-TL
 
TL

I think you called it.... if I rest my thumb on the cylinder while cocking, when it gets to full cock, it is not fully sitting in the lock, almost, but not quite as it is just short.

Yes, the hand is the two stage style. Will replacing it with a new one correct it?

What fitting is required?

Cheers
Mark
 
mravery said:
TL

I think you called it.... if I rest my thumb on the cylinder while cocking, when it gets to full cock, it is not fully sitting in the lock, almost, but not quite as it is just short.

Yes, the hand is the two stage style. Will replacing it with a new one correct it?

What fitting is required?

Cheers
Mark
Click to expand...
Ah! I got lucky this time.

It is probably not the only problem this gun has. Does it have any end shake? How much cylinder gap does it have? Are you shooting black powder or smokeless?

As for fixing it, looks like you are quite proficient on this sort of lock work, and good with hand tools, are you not? If you decide to do it yourself, I suggest first find a replacement hand, just in case.

-TL
 
It did the same thing with the factory spring, actually completely locked up. Had to work with it to get the cylinder to spin free. But again, it only happened with live fire, never with the snap caps.

I did find this on other site and this is exactly what it is doing:

Late Bolt Timing
The bolt drops late and strikes the front edge of the bolt notch. This will cause the front edge of the bolt notch to become crushed (Fig. 1) and eventually result in the cylinder not locking up properly. This is caused by the leg of the bolt that rides over the hammer cam being too long. This can be fixed with minor gunsmith work.

http://www.classicsingleaction.com/opinion

Question is, how can this cause the off center FTF strikes?
 
TL

I only shoot smokeless (Trail Boss).

I don't have a gauge, but the cylinder gap looks the same as on my other Uberti's.

End shake?? what is that, is it a new line dance? :)

I have no issues ordering a new hand or bolt... just not sure what tweaking that they may need once I get them.
 
End shake is the back-and-forth movement of the cylinder in the frame window. It should be no more than 0.002". It is the first thing to check when you are buying a revolver. If your gun has end shake, the cylinder gap should be measured with the cylinder pushed forward. No fancy gauges are needed. Just a plain set of feeler gauge will do.

End shake and cylinder gap need to be corrected first before fixing the timing.

If you really want to do it yourself, I am willing to give you a pointer or two. PM me when you are ready.

-TL
 
Hey TL

Don't have any feeler gauges (but I can get some) but with playing with it in all of the hammer positions, there appears to be very very little movement back and forth...

I'll send you a PM!
 
If you want to check barrel-cylinder gap, see if a piece of plain printer paper (.003") will fit between the barrel and cylinder. If not, the gap is likely too tight; a gunsmith can ream the rear of the barrel to set it to about .006"-.007", which is optimum.

Jim
 
Thanks Jim!

I mic'd a piece of paper to .004 and it fits but it is snug, especially when the hammer is forward. When it's in the second notch it is just a tad tighter but it still fits.
 
.....the gap is likely too tight; a gunsmith can ream the rear of the barrel to set it to about .006"-.007", which is optimum.
Click to expand...

I think I'd be having a local smith do a very small amount of reaming work if you get a tight .004 based on Jame's information.
 
Late Bolt Timing
The bolt drops late and strikes the front edge of the bolt notch. This will cause the front edge of the bolt notch to become crushed (Fig. 1) and eventually result in the cylinder not locking up properly. This is caused by the leg of the bolt that rides over the hammer cam being too long. This can be fixed with minor gunsmith work.

http://www.classicsingleaction.com/opinion

Question is, how can this cause the off center FTF strikes?
Click to expand...

How can it cause off center FTF strikes? Why, because the bolt isn't dropping in time, the hand cannot rotate the cylinder to the full extent its supposed to rotate. When the bolt does drop, the hand has already gone through part of its operation.

As suggested in your quote: get the bolt to drop sooner.
 
What is probably happening is that a too-small gap and/or powder residue is slowing the cylinder so it has to be forced into alignment by the hand. And the hand is a tad too short, so the cylinder doesn't carry up and align, and the primer strike is off center.

If the gun is clean and cool when the hammer is cocked, there is nothing to retard cylinder motion and it carries up from its own inertia.

Jim
 
If it is binding at the barrel, then the hand can be at proper specs, and still not rotate the cylinder fully, as the binding may be enough that the hands spring will just flex, and allow the hand to slip out of the ratchet, instead of turning the cylinder its full movement. Generally, on Colt's and clones, when the hand is all the way up, it's spring has the least amount of pressure on it to keep it engaged with the ratchet.

One can check this spring tension, by removing the cylinder, and cocking the hammer. Place the finger against the hand, and see how easy it is to push inward.
 
In the old Colt DA's there is often a point where, even from the factory, the hammer can be cocked slowly in SA without the full cock notch in the hammer engaging. The cylinder will carry up when the trigger is pulled (unless there is a real problem!).

But in the SAA, the hand is on the hammer and the hand should force the cylinder to carry up if cocked normally. The hammer will usually be stopped by the hand trying to force the cylinder around after the cylinder stop engages. That is not the way it should work, but most guns, again from the factory, will work that way.

Ideally, the SAA should be timed so the hammer hits the backstrap and stops just as the cylinder stop drops into its notch and after the full cock notch passes the trigger/sear. That way, the long leverage of the hammer doesn't force the cylinder hard against the cylinder stop or the hand hard on the ratchet, saving battering and wear on those parts.

Jim
 
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