Fly Removal?

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Idahomie

40 Cal
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Good morning to all you members of the forum! I was hoping I might be able to pick your brain here. I went to shoot a custom Kentucky flintlock I purchased from another member for the first time, and I was quite disappointed to learn that while sometimes the cock will have a positive engagement at half and full cock, other times it would not; in fact, sometimes the sear wouldn’t properly engage, and the cock would fall forward with just the slightest of finger pressure— sometimes it wouldn’t engage at all and would come forward when simply released. It appears as though the fly isn’t working properly and is somehow impeded by the lobe of the fly. There’s actually a small amount of wear on the sear because of this. Is there any reason I couldn’t simply dress the sear edge and remove the fly altogether?

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Good morning to all you members of the forum! I was hoping I might be able to pick your brain here. I went to shoot a custom Kentucky flintlock I purchased from another member for the first time, and I was quite disappointed to learn that while sometimes the cock will have a positive engagement at half and full cock, other times it would not; in fact, sometimes the sear wouldn’t properly engage, and the cock would fall forward with just the slightest of finger pressure— sometimes it wouldn’t engage at all and would come forward when simply released. It appears as though the fly isn’t working properly and is somehow impeded by the lobe of the fly. There’s actually a small amount of wear on the sear because of this. Is there any reason I couldn’t simply dress the sear edge and remove the fly altogether?
If you have set triggers you will have to keep the fly. Check to make sure the fly is not in backwards if it can be put in backwards.
Larry
 
Something seriously wrong with that fly..!

It is either wrongly fitted or has been incompetently replaced. The rear end of the fly should lift the face of the sear over the half cock bent on firing, not catch on it! That is what the fly is for!

The sear should only engage in the half cock bent when brought back from the fired position. The fly should be under the sear in this instance. When the sear comes back to the full cock bent, the fly is released and flips forward blocking the half cock bent. The bottom edge of the fly should be level with the bottom of the tumbler and the top edge with the top of the half cock bent.

In your case, the fly does not seem to be going back far enough in it's notch. check to see if there is anything blocking it...

Although as Larry says, you only need a fly if you have set triggers, I would always keep one if it is there, but get it set up correctly!
 
The nose of your sear appears to be beveled and radiused. Those I have seen typically are straight across at the tip (not rounded or radiused) with closer to a 90 degree angle on the sear nose rather than the chisel-edged bevel I believe I see in your first photograph. I’m thinking you might want to try fitting a new sear.

I also agree with comments above regarding the fly. The sear should not catch on it that way.

With a simple, single trigger a fly is not necessary, although having a fly in there may allow having a lighter trigger pull.

A lot of old sporting rifles with double-set triggers have no half-cock notch at all. The hammer (of a percussion gun, or the cock of a flinter) can only be at full cock or fully down. The half cock notch is the “safety” on a side-lock muzzleloader, and it needs to be secure. That old-time practice of eliminating the half cock is now considered unsafe.

However, what really concerns me here is the unreliable full-cock. That’s an accidental discharge (AD) waiting to happen. Not a good situation, and it needs to be addressed. However, I believe it is fixable.

What kind of lock is that? I don’t recognize it. Parts are generally available for the commonly seen American made locks.

I think this is the third thread I’ve seen in a week concerning recently purchased guns with undisclosed problems. I hope that’s not a trend.

Best regards,

Notchy Bob
 
Thanks, Bob. I’ll take things apart tonight and see if so can’t get a closer look. I’m seriously tempted to temporarily do away with the fly until I can resolve the issue; I’ve got a trail walk shoot tomorrow and my other pistol’s frizzen is undergoing repair/hardening.

I really believe that it’s the fly and not the sear’s engagement that the tumbler that is at fault here, as it does sometimes properly engage— just intermittently.

This is a 1986-marked Blount Co. lock. I believe they were distributed by Dixie Gun Works at one time.
 
While I believe you have a problem with the fly that should not affect the full cock engagement. By the time the sear nose is ready to engage the full cock notch the fly is completely out of the way and shouldn't be a problem unless the fly is way oversize or an incorrect one. The pin for the fly pivot is probably on the fly itself so it shouldn't be possible to install it backwards. The nose of the sear looks rough to me and possibly the full cock notch needs work too.
 
While I believe you have a problem with the fly that should not affect the full cock engagement. By the time the sear nose is ready to engage the full cock notch the fly is completely out of the way and shouldn't be a problem unless the fly is way oversize or an incorrect one. The pin for the fly pivot is probably on the fly itself so it shouldn't be possible to install it backwards. The nose of the sear looks rough to me and possibly the full cock notch needs work too.
Thanks for offering up your assessment. After removing the lock and attempting to bring it to both half and full cock, the fly does appear to be impeding the sear in some way. I’m unfamiliar with this style of lock (and granted, my experience with flintlocks are altogether limited), but this is just what I’m noticing during visual inspection of its operation. If I do end up removing the fly, I’ll obviously do extensive testing to ensure proper sear engagement before I attempt to fire. I agree with the evaluation of the sear… not sure what’s going on there. Any chance it could have been a way of addressing issues with the lock’s geometry? I was told by the seller that it didn’t appear as though the pistol had ever been fired.

Unfortunately, this is the third firearm I’ve purchased from the classifieds that has had issues that weren’t disclosed.
 
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I'd say just dress where it's wearing and keep all the parts. The parts are there for a good reason. The wear is not.
That’s the thing… I don’t think it’s so much wear as improper fitment during the build. Isn’t the fly unnecessary for a firearm with a single trigger?
 
That’s the thing… I don’t think it’s so much wear as improper fitment during the build.....
You might just try polishing the outer surface of the fly itself where it's in contact with the inside surface of the lock plate, and also the adjacent surface of the lock plate. If you've got a tool that can hang on to it while you sand it (!!) Based on your photos, it looks like it's directly in contact with the lock plate, so maybe it's just a case of too much friction impeding its movement, and then it jams up between the sear and the tumbler notch. That hypothesis would support the intermittent nature of your problem.

I'm a little leary of filing on tumbler notches and sears because they need to be nice and sharp and perfectly flat to engage properly and positively, and that's near impossible doing by hand.

All in all, if you can just get replacements that's probably the easiest solution, though it doesn't answer your original question yet, does it? Sorry, I don't know either. I think you're right, but I do have single-triggered locks with flys, but that could just as easily be so that lock can be used with both types of triggers.

Let us know how it works out. ;)
 
Thanks for all your assistance, everyone.

I believe the fly was simply too short to be effective. I attempted to change its angle in order to alter its engagement but was unsuccessful in doing so. I ended up removing the fly, which caused the sear to hang up at half cock, so I chamfered the edge of the half cock notch ever so slightly in order to allow the sear to clear. The pistol appears to function properly now, and the cock doesn’t fall under firm thumb pressure when at either half or full cock.
 

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Glad it's fixed. I think the seller may have known about the problem. Or maybe they acquired and resold it without ever testing it. Either way it's maybe not a good selling practice.
 
Glad it's fixed. I think the seller may have known about the problem. Or maybe they acquired and resold it without ever testing it. Either way it's maybe not a good selling practice.
Yeah… I don’t know. I spoke with him yesterday, and he claimed he tested it— but to what extent? The issue was intermittent, so a mere trigger pull or two wouldn’t be sufficient in this case. The guy’s a national champion shooter and had excellent feedback, so I hate to incriminate him, but the fact of the matter is that this is the third pistol I’ve purchased in the past month that has issues that weren’t disclosed in the listing. Given my luck, I think I may steer clear of the classifieds going forward.
 
Update: I actually ended up reinstalling the fly. While it was marginally too short to be effective with the tumbler in its initial configuration, it did appear to operate correctly after I chamfered the half cock notch.
 
You might want to get a replacement tumbler, sear, and fly because the original owner had changed the sear angle/engagement to produce a light trigger pull. In doing so he screw up the lock and then decided to sell it. That's where you came into the picture. That sear's nose is shaped totally wrong. If you don't feel like replacing the internals then I strongly suggest that you send the lock to The Log Cabin Shop for repairs.
 
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