doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com top screw out of time

the top screw under the lever is out of time. Someone recommended I remove and file material off the bottom of the screw until I can get it tight but in time. Sounds logical. Am I safe doing this?

Nitrah;

Before you do anything ask yourself why it is out of position. When the gun was made it would have been placed in the correct position usually with a lot of force applied to the screw slot. Ask yourself some questions like this: has the gun been re-stocked; does the butt stock now have a great deal more expansion to it because of the humidity where it now resides; is there any thing interfering with the original stockmaker cuts allowing the bottom tang of the action to come into its original position; do you have a screwdriver(turnscrew) of proper size and strength to tighten the screw--if it is a British made gun it originally was likely tightened with a brace. If you do not know what a gunmakers brace is then watch some of the Gunmaking.UK series on youtube.

I do not recall every finding a top lever screw (breech screw/pin) that needed to be filed such as you described, it was always something else that kept the screw from going to its proper position.

Kind regards;
Stephen Howell

Stephen, thanks for responding. It could be a restock, it is a C Boswell pigeon gun from the 30's and stock is in remarkably good shape. I have a proper turnscrew, but not a brace. It is tight with the slot at 3 o'clock

I would certainly follow Stephen's advice,, but what would filing material off the bottom of the screw accomplish, wouldn't you have to remove material from the bottom of the screw head to have a turn in tighter?

Nitrah;

Being tight at the 3:00 o'clock position could be a symptom of the hand of the butt stock shrink allowing the breech screw to turn too far.

Stephen Howell

The question I would ask is if the screw has turned beyond its original position or if it’s not all the way back to the original position. Then determine why it’s not in the correct position. If it’s gone beyond you might consider a spacer to line it up.,

I'd be leery of filing off the bottom if I thought it would leave the head of the screw recessed.

I'd be more inclined to add a spacer.

Rather than guess, you can do the math.

It sounds like you were 90° off.

90° less? Or 90° more?

What is your thread pitch?

How far in does the head of the screw go in 360°.

A piece of feeler gauge approximately 1/4 in thickness of that distance should give you a very accurate shim to place under the top strap if you want to.
No machining, just a pair of scissors.

Action pins are usually made out of low carbon steel. And then hardened. Simple fact is that over time, and depending on how the pins were initially fitted up, and even how good the threading dies and taps the craftsman was using when he made the pins, to how many times they’ve been loosened and then torqued down…they can wear out and start to over turn or go past their intended index point. You see this not only with breech pins, but on top lever pins, and cover plate pins.
As Steven has mentioned the breech pin out of index can be from a number of different causes, as can the hand pin. These two pins do more than just hold the stock onto the action. The breech pin actually bears on the wood and when tightened will draw the head of the stock tight into the action. That’s why that pin is normally tapered.
Nobody notices a hand pin that isn’t tightened down completely because its slot is hidden under the trigger guard tang in most instances. Take a few guns down to the bits and you’ll start to notice that hand pins are usually pretty loose. Tightening them down will draw the rear of the top strap further down and you’ll start to see the pin protrude from the top strap, which will need to be filed flush so the safety will work correctly and for aesthetics.

I don’t think I’ve ever heard of or seen a craftsman using spacers to correctly index a pin. Can you provide an example of this method (pics or vid)? I’d be interested in seeing the method.

Most craftsman will just make new pins to fit. I’m making a few right now. I just finished up making two new cross pins for a Greener FP.

A shim is a stopgap for most folks until the gun can be properly repaired if the cost of repair is warranted by the value of the gun.