doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Loose Action, or not. Definitive Answers

I expect that this topic may have been debated in the past, but I'm curious about any specific ways to MEASURE if a gun is on-face or not. I am not talking about a gun that you can easily move and feel the action when closed. I'm talking about a situation where one person says "it's tight" and another says "I feel movement".

How do you measure it? Is it always by "feel" or does one put a piece of .00x" shim stock in and pull on it???

I've found that holding/shaking barrels with action locked and fore end off will sometimes give you a feel of movement that's difficult to sense by just trying to move the receiver.

Thoughts?

You can have a gun that is on the face and have adequate bite , that is lose in the action when the forend is off or when the gun is opened . Alternatively you can have a gun that is tight in the action but off face or have no bite .The again you get some guns that are just sloppy ,off face and have no bite at all .
There is no one size fits all answer , it is a matter of degrees of what is acceptable and when it need to be rejointed .

Prepping a gun for proof in the UK, it has to be tight in the action , on the face and have more than normal bite with no forend on .

When I was an apprentice working on new guns I was taught that to be correct the weight of the barrel should be enough to open the gun [drop gently ]when the lever was opened so it was a combination of barrel tightness in the action and bearing of the forend .

when a gun is fully assembled and in firing position there should be no movement of the stock, action, barrels or forend. any looseness will cause gun to wear faster and perhaps the wood to crack under the stress of firing.

off face means many things to many people. to me, it means being able to see day lite between the barrel breeches and the vertical face of the action. some day lite may still be safe for shooting, depending on the gun and the ammo. if you see day lite, seek professional help. and if the day lite measures less than .002, seek a second opinion, if facing a costly repair.

The following is by my own definitions of the matter of off the face and loose actions.

If i say an action is tight i mean to able to close the gun normally and feel that the bolts are securely engaged in the bite thereby holding the barrels firmly closed.

On very worn old guns you can sometimes feel or in worst cases see that the the forend is loose on the bearing which makes the gun feel sloppy and flop open.

Sometimes the bite or bolts are so badly worn there is some up and down movement in the barrels when closed normally.

By my definition either of these two situations describes a gun with a loose action.

A gun either has a tight action or a loose action, there is no middle ground, or allowance made for the age of any particular gun.

I have a gun going left of center and i will get it tightened, though the gun is not obviously loose, the left of center is a good indication of the gun wearing in and constitutes normal wear for an gun that's been shot.

I have tightened loose guns before and in the case i refer to it required the barrels to be put back on face from wear on the pin, the hook had to be welded, once this was done this bought the for end back onto bearing on the knuckles, then we had to tighten the bite, combination of this work took a lot of time but ended up with a gun that opens easily without play between the knuckles and forend, closes securely with the barrels on face, and the action tight.

I gun may be tight and on the face or tight and off the face by my definition.

A gun that is off the face by my definition is a gun that's barrels are no longer making any kind of contact with the breech face.

A gun that is tight and off the face my feel like a perfectly find gun however if shot wear will quickly turn the gun loose.

A gun that is loose and off the face will feel awefull, the forend may move against the knuckle, the barrels will drop open heavily and jar closed then the locking mechanism will hold the gun closed but there will be play in the mechanism.

I think the best way to judge is by feel,

If one person "feels" movement and one does not, how can this be measured ??

You say that a gun is either loose or tight. It just does not seem that black and white in all cases, that's why I asked.

If I put a .001 inch piece of steel shim on a pivot and the gun closes, is the gun loose?

My method is to remove the forend, turn the gun upside down so it will stay closed, push the opening lever to the right and then shake it from side to side. If it is loose, you will definitely feel the movement.

The off face but tight comment is true. I have a Jones underlever gun in now that is severely off face but locks up tight. Moral of the story is shaking the gun doesn't always tell you everything.

DW444 I assume when you say left of centre you are referring to the position of the top lever when the gun is closed ?
This will of course depend on the type of lever work the gun has but it is more than likely wear on some part of the lever mechanism than lack of bite and/or the condition/state of the joint .

I did mean that gunman yes.

Left of center; if you soot up the bites and close it you can see how much contact you have between the bolt and the bites, on the one boxlock gun i have that is left of center if i soot up the bites and close the gun the under bolt closes and makes contact with the back of the bite, the underbolt is wedge shaped which allows that as the bolt and bite wear the bolt bolt moves slightly further forward, the wedge shape compensating for wear, however at some point you will completely run out of wedge toon the underbolt to take up the wear eventually the under bolt will wear out and the gun will slowly become loose.

Dovetailing in the bites or underbolts or decent welding can help tighten a loose action.

You are quite right however, this only applies to certain mechanism in certain guns, most my hammer guns have top levers that couldn't not even move left of center weather the action is tight or loose.

All i mean to say is if you have a gun that feels rubbish and the lever is left of center its possible the action is loose though there are so many factors that affect how a gun "feels"