doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Thoughts on an action going off face

I send my doubles to Brad Bachelder, a master gunmaker. He's had a couple of mine micro welded, then did the necessary machine work for a perfect fit. His phone number is 616-459-3636 Good luck.

Stan, I have no idea, just guessing possibilities. I'm sure not a gunsmith--even screwdrivers scare me.

Stan;
One other question to consider, which was hinted at by another poster. Is it possible there has been a bit of clearance on the right side ever since you had it, even when it was new. It was tight & on face & you just never particularly noticed it. After all these years of use, maybe it only wore about a .001" in the joint but that was just enough for you to notice the looseness & upon giving it the real look over you found this .004 on the right side. Maybe it left the factory with around .003" but you just never examined it that critically until you felt that play.

Stan et al;

When I read your post yesterday I thought about responding straight away, but as I knew this post would generate significant interest and comments I wait until now.

Firstly, let me say that my experience is gained from restoring English shotguns and building double rifles, most recently the building of a double rifle using the "shoe lump" method used by the likes of Verney-Carron and Heym. If you are not familiar with the shoe lump method of attaching the lumps to the barrels, view one of the Verney-Carron videos on You Tube to see how the shoe lumps are brazed to the barrels.

Secondly, let me say this is not my first rodeo, as I am 75 years of age, and began my interest of above in the early 1960's.

It has been my finding that it is most common to find a double shotgun of common quality where the face of the action is not square with the center slot. The center slot of a double gun/rifle action is the datum where every other measurement of an action should be referenced. For each action that I use where I build a double rifle I build an individual precision test mount that fits into the action middle slot from the bottom of the action. The test mount with the action securely attached is placed in a milling machine and and the action face is measured via instruments to determine if the action face is square to the center slot. If the face is not square to the center action slot, I mill it square before starting my work. I work from left to right measuring the action face. The current action that I have just used to build a DR was 0.009" left to right out of square with the left starting point being set at 0.000". I have found an action that had 0.017" out of square runout across the face.

Now of course, when the action is out of square with the center slot, a set of barrels with the lumps made to fit into the action center slot will have to be faced "off square" to the barrel lumps, which in and of itself is not a difficult task for a gunmaker. However, when the gunmaking process is "machine made" a tolerance measurement will be used in fitting the barrels "to face". This tolerance will have a +/- range and some guns will be finished very tightly on face and some more loose on--but all within good engineering practices.

Specific to your out of face gun, clean the barrel hook with laquer thinner and apply one piece of aluminum or magic mending tape to the barrel hook to determine how many thickness of tape required to tighten the action to the barrels. Aluminum tape used by HVAC techs is the best for this exercise. Of course, measure the thickness of tape with a micrometer before you begin.

Remember that if the action is 0.004" off face, it is reasonable to expect to have to make a new hinge pin 0.009" to 0.012" larger diameter as some metal will be required to scraped from the hook to fit the new diameter hinge pin.

Stan,

Several previous posts hit on some pertinent issues:
1. Some years ago, a friend of mine shot an double off-face with less than two boxes of shells.

2. Even though you are shooting it a bit hot, it is probably safe to shoot as is.

3. I could be wrong, but I believe that you can measure any damage to the standing face by aligning a right angle micrometer ruler to the left side and looking for the hint of light that was previously seen on the right side. ( I too think that the more likely problem is a worn pin. It is sometimes difficult to understand how torque will cause cant when leverage is applied.)

Steve

I once made the mistake of shooting a hot dove shoot with an severely off face Beretta model 410. The gun stopped ejecting, then became difficult to open, and finally wouldn't open at all. That evening I took off the for-end to open the gun and noticed the bottom rib had come loose and developed a set of waves.

What had happened was the movement caused by the off face condition of the action had broken the weld holding the fore-end lug to the barrels loose. Mike Orlen put it right and I'm still shooting the gun today, but I won't shoot a loose gun anymore...Geo

Interesting comments bushveld, thanks for taking the time.

Thank you, bushveld, for that informative post. This gun may well have been made out of square, it may have been very slightly off face on the right barrel when I bought it, or it may have become out of square due to shooting the right barrel so much more than the left. Whatever the cause, it is indeed off face now, on the right side only. I will try to make the time to see if a hook/pin shim will allow it to close, but I will be surprised if it closes up the .004" gap at the right barrel breech completely. 'Twill be interesting to see, tho'.

I know it is still safe to shoot, but I just don't want to do so anymore until it is put back on face properly. More reports after I try some more shimming.

SRH

Bushveld

Thanks for posting your note. It is a great example of the type of posts that make this forum worthwhile.
Very educational.

Jeremy

I still have one BSS that is like this, and has been as long as I have owned it. Some of them were fitted using the forend to pull the barrels snug to the hinge pin Thereby leaving the barrels not seated on the breech face. The forend loops are silver soldered on so this works. It is not right , but it does work. I'd work on the forend iron fit to pull it tight against the pin again. Don't try and have someone weld up the hook and refit as the lumps were brazed with some alloy rather than silver soldered. Been there...