Is this to thin to be safe?
 

I am by no means an expert on this so I am asking the question. To preface it, I know that minimum wall thickness matters the most on just where in the barrel it is measured. Having said that, and if you do not know just where the measurement was taken, a Damascus barrel measures .020 and .019 for minimum wall thickness would most consider this gun unsafe to shoot no matter where in the barrels it was measured? Thanks, Steve

For me it would depend on where the measurement was taken. If it was from out towards the muzzle end of the barrels I would shoot it all day long with low pressure loads. If it's the back half of the barrels towards the breech I would probably not, or only light black powder loads.

I would shy away from it but with those measurements in the forward 1/4 or so of the barrel it’s probably ok to shoot light loads IF IT DOESN’T have tight chokes. How tight is anyone’s guess. I once had a C Grade Fox 12g with Krupp steel barrels that a hacker “gunsmith” bored out beyond what we’d agreed to, and the remaining walls at the choke leades were .018 and .020” thickness. It only took one round of clays (50 shots each barrel) with Remington Gun Clubs before I saw bulges at the start of both chokes which were both Full at 36 and 40 points of constriction. Barrels ruined, lesson learned. :banghead:

More information on this gun. It has 26" barrels, and the seller advised that the measurements were taken "somewhere in the last ten inches" of the barrels.

Steve, given it's a 26" gun, it is more than likely IM & Mod. I'd verify the sellers info, but I'd probably shoot it and not even think about it, provided there were no dings, or gouges on the outside, corresponding to the thin points on the inside.

That is pretty thin. But not unheard of even on original barrels. The more important thing is the measurements at the front of the forcing cones and in the first 10” of the barrels.

Cannot help but violently agree with what Frank ("Cold Spring") just posted. I consigned a beautiful CE Grade A.H. Fox 16 ga. light upland bird gun (26" #4 wt. barrels) to the last G&D auction in September that was originally chambered for 2 1/2" shells and had been opened up to 2 3/4" chambers and so marked on the barrel flats. I purchased the gun that way before the "Hosford gauge era" and have no idea who did the work.

Accurate readings using Hosford gauges showed the right barrel wall thickness at the forcing cone well withing acceptable limit but the left barrel borderline at the same distance. The pre-auction estimate on the gun was $7500-$12,500, but when the lot came up, no one would go for the minimum of $3250 (the required 1/2 lower bid estimate to open).

This tells me that savvy and meticulous people who want these guns are not willing to 'push the envelope' with guns of this configuration in hopes that the inevitable never occurs. And there is no guarantee that some nimrod will stick to lowest-RST ammo use and not cram a Fiocchi 1 1/8 oz. "Golden Pheasant" load into it someday.

My personal theory is that whoever opened the chambers used a motorized tool, not a hand reamer. I have watched enough chamber hand reaming done the right way; e.g. a few turns of the tool then careful measurement before continuing.

Net result is that now a beautiful and desirable Fox will be sold at salvage to someone skilled and talented enough to rebarrel it. Upside is that one very viable candidate has expressed an interest.

There are many original condition O frame Parker 20's with min wall in the mid .020's. Personally .019 is too thin for me.
I recently measured a O frame 20 that had the chambers extended to 3". The measurement in front of the chamber was .088 and min wall of .022. Not a gun I wanted to shoot, but others would have no problem with it. It all comes down to how much risk do u wamt to take.

Looks like I'll be calling Hosford.
But really isn't it the practice of checking the barrel after each shot for debris that determines the possibility of an accident?
Another question, how many times would a gun have to be shot for there to be wear on the barrel wall?

This has been an interesting topic for me for years and I have kept a log of all guns I have measured. I believe the OP is getting reasonable and valid responses from others.

That said I have always been amazed at some of the measurements I have found (using Hosford gauge) on original chambered guns between chamber and forcing cone. Here are a few which cause me to ponder my personal limits since I would consider these original chamberings.

**Measured at point between chamber and forcing cone

1894 Parker (Dam) 16 gauge, 0 frame, 2 1/2 ch - .070/,075
1923 Parker (fluid) 16 gauge, 1 frame, 2 1/2 ch - .084/.084
1905 Parker (Dam) 16 gauge, 0 frame, 2 1/2 ch - .088/.096
1902 Parker (Dam) 20 gauge, 0 frame, 2 1/2 ch - .086/.089
1920 Parker (fluid) 20 gauge, 0 frame, 2 1/2 ch - .080/.097

I am in no way giving advice on personal limits. I am just pointing out there are original Parker small bores out these which would not conform to some of our personal limits.

Checking the barrel for debris only prevents an obstruction leading to a burst barrel. The "wear" on a shotgun barrel referred to is due to not wear but by removing metal by reaming. I've always measured the bore and chamber diameters and if they are within specs for the gauge then that's good enough for my purposes.

Shooting a gun does not wear down the wall. The walls get thinned out either by honing, backboring, exterior refinishing or… they were just made that way.

An obstruction will blow out a thin walled barrel and also a heavy walled barrel.

You need to get measurements at other more critical locations on the barrel set to make a completely informed decision.

Here's a pic that follows on my post of yesterday. C-Grade Fox 12 ga with Krupp steel barrels, honed oversize by a hacker despite agreeing to a lesser overbore. Before the work he claimed to have a precision Sunnen hone but miking after the work showed an irregular succession of thin spots here and there. Wall thickness on this tube was .018" at the leade of its choke, and less that 50 shots with lighter factory ammo caused the bulge with its heavy choking. The other barrel was .020" thickness and it also bulged. As I'd posted .... lesson learned on thin barrel walls; and who to trust work to. After this episode all my necessary bore honing has been done by Briley.
.

So, plan is to get a Hosford gauge, measure barrels, especially those where the chambers are 2 3/4, and not have any more work done to them.
Shooting them will not wear them out.
Use only light loads, even in repro Parkers.
As I am learning, heavier really doesn’t mean any better to break a clay.

Now you got it. Especially the not needing heavy loads to break a target and beat your shoulder.