gap between action & barrel flats

[swan40]

Could  anybody tell me  what the acceptable gap is between the barrel flat and the action flat on a english side by side is please

[JJsDad]

I have never heard a maximum figure quoted, however by design there will be a clearance of a few thou. More important (to me) is that the barrels are tight back against the standing breech when the gun is closed and there is no evidence of play between the barrels & action (fore-end removed) when the stock is given a sharp tap with the heel of the hand.

The man to answer this is `Gunman`; I would be interested in his comment because its a question I have never heard raised before.

[panoma1]

None! There should be no visible gap and no discernible movement! 

[swan40]

The no movement bit I get but you think there should be (idealy) no visible light shining through ?  . I have tried to read up on this but can not find much information .

[JohnfromUK]

22 minutes ago, JJsDad said:

I have never heard a maximum figure quoted, however by design there will be a clearance of a few thou. More important (to me) is that the barrels are tight back against the standing breech when the gun is closed and there is no evidence of play between the barrels & action (fore-end removed) when the stock is given a sharp tap with the heel of the hand.

The man to answer this is `Gunman`; I would be interested in his comment because its a question I have never heard raised before.

This would be my view as well.  It is not much more than a cigarette paper though.

[JJsDad]

35 minutes ago, panoma1 said:

None! There should be no visible gap

You are in contradiction to the late Gough Thomas. Have a read of `Shotguns & Cartridges for Game & Clays` in particular how an action is fitted to the barrels in order to allow flexing of the bar during firing.

[swan40]

I will  look up the book you mention sounds interesting but I guess the gap is more fag paper rather than cardboard box or dose it not matter 

[panoma1]

3 minutes ago, JJsDad said:

You are in contradiction to the late Gough Thomas. Have a read of `Shotguns & Cartridges for Game & Clays` in particular how an action is fitted to the barrels in order to allow flexing of the bar during firing.

Apologies, I misunderstood/misread! I was referring to the standing breech and the barrels! I am aware there needs to be a gap between action flats and barrel flats, but I don't know what it is! 

[JJsDad]

9 minutes ago, swan40 said:

but I guess the gap is more fag paper

Just checked in the book I quoted earlier, and Gough Thomas merely says a clearance to allow flexure of the action bar when firing. He is politely critical of a dealer who condemed a gun for showing a trace of daylight between the flats. So highly likely that individual action filers had their own tolerances that they worked within and there was no generally agreed maximum.

If the barrels are tight against the standing breech but you have a fag paper gap, I dont think you have anything to be concerned about.

[swan40]

the gun I am concerned about has a gap that a luggage label( you know the ones with a bit of string on ) can easily  be entered between the barrel and the action flats -maybe even folded over but I haven't tried it. The gap is big enough to see quite a bit of daylight through but not quite big enough to get a slice of toast through - the flats I am talking about not the standing breach.

Edited March 23, 2018 by swan40

[yorkierm]

A shotguns barrels should not sit on the flats.  The small gap exists to allow the barrels to close square on the breech.

 

The better the gun, the smaller the gap.  Truthfully the size of the gap is (within reason) meaningless I think as it has no bearing on the strength of the guns mechanical lock up, that being achieved by the breech face, barrel wall thickness, and hook, lump and hinge pin etc...  But it does have cosmetic value.

 

As long as your barrels are on the face (test by removing the forend and seeing if they wobble on the action), and your strikers/firing pins are hitting centrally on the primer then your gun, while not looking quite perfect, should be ok. But as with all these things, if it concerns you or you think your gun is loose or off the face, take it to a reputable gunsmith to either repair or ease your concerns.

 

Also remember that a gun can be loose, but still on the face and simply require tightening...but a gun that is off the face requires re jointing... While tightening an off the face gun will give the impression (for a few shots) that it is back on the face...

 

regards

 

Yorkierm

 

Edited March 24, 2018 by yorkierm

[figgy]

One thing i watched on tv or online was an old gunsmith re jointing Tightening a gun up to put it back on face was that if there was no gap left between action and barrel flats it makes it a lot bigger job to rejoint the action. 

[yorkierm]

Depends on the re jointing method used mate. Fitting a new hinge pin will pull the guns barrels both back, and down, so if there is already no gap, then you have a lot more adjustment to do with a file, as you have to carefully file the hook in order to bring them back into place.  This is done by smoke blacking the barrels, assembling the gun, and seeing where they touch, then filing the hook to adjust, before finally honing the barrels back onto face with a fine stone.

 

TIG (or laser as its far more precise) welding the hook is another acceptable method, where by you add beads of weld to the hook to add material.  Again you need to hand file it all back into place, but by being clever with where you add the weld on the hook, you can move the barrels slightly relative to the position on the flats etc.

 

Tightening the gun simply adjusts the amount of bite the locking lug gives, as a user you would notice that the top lever sits more to the right, as opposed to over centre.

 

regards

 

Yorkierm

[swan40]

The barrels of this gun have recently been sleeved and reproofed . The barrels match up to the action well and do show any sign of being a bit high in relation to the top of the action in my very amateur opinion .  Is it likely the gun just could have been made like this in the first place , it is  not a cheap poor quality gun and as its just been proofed safety should not be a problem however it just dose not look right to me . The barrel flats have  the new proof marks with no sign of the old ones which could have been filled off  before reproof making the gap larger but as the gun is very old the proof marks would have probably been on the barrels anyway and now sleeved so long gone.

The gun is under leaver and dose not close properly when the barrels are on OK without so this may tie in with above post

Edited March 24, 2018 by swan40

[yorkierm]

Is it possible to put up a picture of what you mean? 

 

Sleeving won't move the position of the lumps, so if the barrels are sitting high on the action, it is unlikely to be a result from the sleeving process.

Are the strikers hitting centrally on the primers?

[JohnfromUK]

11 minutes ago, swan40 said:

The barrel flats have  the new proof marks with no sign of the old ones

In my (limited) experience - old proof marks would be on the barrel flats.  In sleeved guns I have seen (and own), the new proof marks are added to the old proof marks (along with being marked sleeved).  Sometimes some marks are on the barrels, but usually very near the edge of the flats, so remain on a sleeved gun.

[yorkierm]

Yeah I am certain new proof marks are added and you cant remove the old ones...

 

I have also never worked on an underlever locking gun, but looking at some online the barrels sit flush or lower than the fences of the action, so if the barrels of yours sit proud of the action then I would suggest that's not quite right. And if anything could be the result of a poorly done rejointing in the past, prior to your ownership, rather than having originally been made that way.

 

How old is the gun? 

 

Like I say can you get any pics up? And are the strikers hitting centrally?

[JJsDad]

3 minutes ago, JohnfromUK said:

In sleeved guns I have seen (and own), the new proof marks are added to the old proof marks

As John has pointed out, normally after sleeving the new marks are added to the old. However, I saw an English sidelock at an auction a few years ago that had evidently been submitted for re-proof and failed. To show it was out of proof a vee shaped portion had been cut out of one barrel and the existing proof marks barred out on the barrel flats using an `X` metal marking stamp. Whether this was done by the proof house or the gunsmith who submitted it was unclear. If your barrels had been treated in the same way, whoever sleeved it may have had to remove these stamped marks by filing the flats to tidy them up, which would account for what you describe as a larger than normal gap. You have indicated it was recently sleeved and re-proofed so having a word with whoever carried out the work should shed some light on what you consider is the problem.

[Gunman]

There needs to be gap or clearance between the barrel and the action flats . Webley and Scott [where I worked for 9 years ] made the gap .002"/003"at the front and .004"/.006" at the back .The London trade worked on between .0015" front and .002"/003" at the back on new guns . Re-jointed guns may have had slight differences dependent on how it was done and how loose or worn the gun was before work started .After proof the high spots from the stamp marks needed to be polished down to ensure no fouling .

 

Reproofed guns and sleeved guns sometimes had old marks taken out dependent on how deep they were and who did the work . In the past I have done this where possible especially if there was more than one set of marks if it was practically possible without taking too much metal away thus leaving a larger than necessary gap .

 I have sleeved a lot of guns and re jointed many many more and no matter how hard you try it is not always possible to make any old gun like new so occasionally you did get less than prefect results in the under barrel spacing .

 

[swan40]

Thank you all for you input . I think Gunman probably sums the situation . The trouble is once you know it is not right it is all I can see , although other people probably would not notice.