doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com On face but barrels not tight to frame at lockup

I have a nice Japanese box lock/extractor gun. Has chopper lump barrels and double underbite. Pretty typical stuff I think.

I noticed that at lock up there is a very small bit of wiggle. So after looking it over this is what I found. The wiggle seems to be up and down not side to side. When you put upward pressure on the barrels the fit is tight as a vault with no wiggle left or right and no gap at face. It seems the interface between the locking bolt and lug surfaces are not as tight as they should be thusly holding the barrel flats down tighter to the frame table.

The lever is just ever so slight left of center.

Does this make sense and what is the recommended fix?

Thanks

One more thing to consider….is your top lever spring strong? It’s it’s weak and is starting to have a little spring back…then that should be looked into.
If it’s strong, and the gun still snaps close with authority, then yes, you probably have some bolt work to do. If you can smoke it in and see where is not “biting” that’ll give you a good idea on how much material will need to be added. It won’t be much. Adding some material to the bolt locking surfaces via tig or laser welding and then refitting should give you plenty of bite.

When you push the barrels down is there any gap between the bottom of the barrel flat and the action ?

It may well be the bolt that needs attention, but note that the barrel flats should NOT be snug down against the action flat. There should be almost no daylight visible at the very front of the juncture, but an increasing amount visible towards the rear. This is by design. The "tightness" should be at the hook/pin relationship and the barrel breech/standing breech relationship. The barrels' breech faces should "seat" snugly and with much contact with the action breech, thus stopping the breech end of the barrel flats from contacting the action flats.

Of all the break action shotguns that I've had, the breech face has never been a component of the lock-up. And I have to admit that watching the best Perazzi 'smith in the US fitting a number of barrels for me revealed only his interest in the proper fitting of the flats and the bolt. Ejectors may rub on the standing breech but not the barrels proper.
IIRC you have a Perazzi that is mondo difficult to open. Lucio could fix that badly fitted barrel for you in a couple minutes. You'd be amazed at how easy a Perazzi is to use when it is right.

Just a thot

Of these two vastly different opinions, I'd have to agree with Stan rather than Dr. Wanker. Loss of contact of the barrels with the breech face is a problem. In fact, there is a commonly used term for it... "off face", or as the British say, "off the face". And the rear of the barrel flats should not contact the water table. All of the informed sources I've read on this subject also agree with Stan, including "Shotgun Technicana". Here's a link to a pretty good article on the subject by gunsmith Delbert Whitman:

https://shootingsportsman.com/re-jointing-a-gun/

On most, but not all double shotguns, the top lever going left of center is a clear sign that the bolting surfaces are worn. This is also covered in the link above.

Of course, Dr. Wanker also seems to think the gun in question is a Perazzi, when the OP clearly states that it is a "nice Japanese box lock/extractor gun". Who knew that Perazzi's were Japanese??? Another Mystery of the Cosmos Unlocked, I guess! Same intellect that says Biden is better than Trump.

Blacking to barrels down wanker. Fit the hook the circle and the face

Re the barrels fitting tight to the action flats, actually they should not. The fit there must give some room for the flexing of the action during firing, in gunmaking language the barrel flats should clear the smoke. The tight fit is between the breech ends, the bottom radius of the barrels and the breech face.

From the description, that the play is only vertical and the breech face tight, plus the leftward top lever, it seems that the wear is on the bold bite.

I guess that I need to get every one of my guns attended to since they all come down solid on the flats and the bolt holds them there. And what possible reason could there be to allowing flex in the lock up?
And just to be clearer, on face/off face is the Result of properly fitting the hinge pin/hook and the flats.
I'm fairly certain that Lucio Sosta, a Beretta factory and later Perazzi factory trained gunmaker, knows how to fit barrels and locking bars. And that's how he does it.
Good enough for me.