Wall Thickness Gauge

[Big Friend Ten (BFT)]

Mark,

I wrote the above post in the dark of my deer blind. I thought it was Patrick's original post and I know he is a Marine reservist. Although I do not know you, the same may apply. Your initial reaction to the buyers BS may have scared him off.

[Bruce Day]

I do not speak to all barrels of various makes of shot guns, however, I do not own a wall thickness gauge and do not feel that I need to. I own a bore gauge from Brownell's and use that. I believe that if a barrel is at or near nominal ID for the gauge, then the barrel remains close enough to original specifications to use cartridges producing pressures for which the gun was intended. I believe I know general original wall thickness of Parkers for example sufficiently enough to conclude that an overbore of several thousands will not reduce wall thickness to dangerous thinness. It is only when the bore gauge shows a large deviation from nominal that I would be concerned.

I am not a dealer, table top or otherwise, not a seller and rarely a buyer. If I were a dealer of shot guns, I think I would find that many buyers would want to know wall thickness and some would not be comfortable in knowing only bore ID. I think it is great that some such as Jay Schachter state wall thickness.

[Hammer Gun]

Dean, It seems hard to get an exact measurement from one of these gauges when you are holding one end with your hand and guiding it through the barrels. seems the chance of moving the gauge inadvertently up or down or sideways would skew the results, also seems the weight of the arm albeit very small would make a couple thousands difference. It seems you would need a "guide to put in the muzzle end of the barrel to keep it in the center and give a much more accurate read and not be subject to hand movement, but I do not own one of these gauges so have just seen them demonstrated at Deep River, Gary

[Brush Buster]

I do own one of the Hosford gauges and measure BWT on most every gun I purchase ,as stated if you in fact move your guiding arm up or down it changes measurements decidedly but if you take your time and watch as you guide it down the bore over and over you can come up with very similar results with each measurements ! To be quite honest , it is an enjoyable task but mostly what I use my gauge for is pitting , it is very easy to look down the bore and see a pit but you have no way of knowing how large or especially how deep it extends into the wall of the barrel ! These gauges are great for this type of measuring ,the head will drop directly into the pit and without any doubt you know instantly how deep it is ! The gauges are expensive but so are Higher Graded Parker Guns and much more so if the Barrels are bad and you are stuck with it !!!!!!!!!!!!!!! When I buy any gun ,especially on line I always request at least a three day inspection and return period and this time is used to measure the BWT , it is most helpful with the Damascus Barreled guns which seem to have the most pitting ,probably because of the age of the gun and the powders burn't in them early on ! I feel the Gauge is money well spent , but it is Just my Two Cents worth of opinion !

[Dean Romig]

Right Russ, and the corrosive primers of the day as well.





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[Drew Hause]

Using a wall thickness gauge is not difficult, but takes time, and is a 2 man job; one manipulating the gauge and the other to rotate the barrels (because of eccentricity) and record results.
One word of warning.
I've measured refinished barrels with bores at the expected factory dimensions, but the exterior of one 16g barrel had been filed to remove pits, and the wall thickness was .016”, 14” from the breech. It had survived 250 2 1/2” Polywad Spred-R shells, 100 2 1/2” 7/8 oz. at 1145 fps. (about 8000 psi) loads, and 2 cases (500 shells) of 2 1/2” RST 3/4 oz. at 1100 fps (4,600 psi per RST) without rupture or dimensional changes.

And at the risk of repeating myself a dealer reporting "MWT is ____" is totally inadequate

[Opening Day]

Originally Posted by Gary Carmichael Sr

Dean, It seems hard to get an exact measurement from one of these gauges when you are holding one end with your hand and guiding it through the barrels. seems the chance of moving the gauge inadvertently up or down or sideways would skew the results, also seems the weight of the arm albeit very small would make a couple thousands difference. It seems you would need a "guide to put in the muzzle end of the barrel to keep it in the center and give a much more accurate read and not be subject to hand movement, but I do not own one of these gauges so have just seen them demonstrated at Deep River, Gary

Gary, you do not hold the barrels with your hand, you place the barrels on the mandrel that comes with the gauge, the only part of your hand that you use is your one finger to slide the gauge down the bore, if you are doing it any other way it's the wrong way...

Is this gauge expensive, yes but if I had had it before a certain auction I would not been stuck with a gun that the auction house said was thirty thousands and it turned out to be fifteen a very expensive mistake on my part so it can pay for it's self in one use !

[OH Osthaus]

Originally Posted by Dean Romig

Right Russ, and the corrosive primers of the day as well.
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correct - black powder often takes the blame for the damage the corrosive primers did- many guns from the 20th century that never saw BP show pits-

all due to the primers

I have a Manson gauge - certainly not the quality of the Hosford - and not the price- it took practice - but i can get repeatable measurements - the biggest drawback is the tip is round and will not go in a pit

i have wondered if replacing it with a 60 degree tip as I use for bamboo planning forms would do it

[Dean Romig]

That would make perfect sense Rick.





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[edgarspencer]

A friend has a Hosford gauge, and I have one similar to Dr.Drew's. If operated as shown in his post, you will get an accurate measurement, though it can be tricky to "zero". Using either, a very light hand is required. A heavy fisted operator will deflect the rods and any reading will be suspect.