Wall Thickness Gauge
 

Could someone teach me or tell me about how this is done
I have seen many testers all being the battery type
Can those be used?
Thanks for any help.....


Mark

Probably the best one you can get is the Hosford wall thickness gauge. very simple to use. I wish I had one..... they're a bit pricey, but worth it if you're going to measure a bunch of gun barrels.

Oh, it's not a battery operated tool.






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not sure what the battery powered version is - unless its an ultrasonic thickness gauge

the wall thickness gauges i have seen and used have been manual- using parallel rods and a dial indicator

What Dean said. I bought a Hosford gauge some months ago, mostly to make sure the guns I own are all safe to shoot. I anticipate using it any time I decide to buy a vintage gun, even taking it to gun shows. The Hosford gauge is very easy to use after getting used to the technique, and is not battery operated. There's other gauges out there, but the Hosford can certainly be considered one of the better ones. Pricey? Yes. But sometimes you just bite the bullet and go the extra mile for any number of your own reasons. Good luck.

Part 1
https://www.youtube.com/watch?v=1jQZn4kohH4

Part 2
https://www.youtube.com/watch?v=sfBP7a0TbjM


Henry gauge that I will have in Vegas

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The barrels are secured to a weighted box (in which I carry the gauge and a bore gauge) with bungie cords

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I affixed a tape measure so the rule is not needed

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I am curious if any of you that own a Hosford gauge and use it daily have found a way to make it produce invalid measurements? I am asking because I was selling a gun last year in Vegas and the gentlemen asked me the MWT on the barrels and my response was " I don't know, the bore measures .730 in both barrels and my assumption is the barrels are factory original”. He then asked to take the barrels into the dealer room and have them measured with a Hosford gauge by an expert. I agreed and 30 minutes later he returned and told me my barrels were thin and my gun was unsafe. I did not agree with this assessment and when I asked who and what he simply walked away without providing any details.

So, I am wondering if you did a blind test with 3-5 people and 5-10 barrels what the results would be using a Hosford gauge? The barrels on the gun in question are .730 on by skeets gauge and I believe them to be factory original on the outside. So I am curious what a blind MWT test would reveal where the idiot running the gauge has an outcome in the results. Perhaps if John Hosford is in Vegas with his tool we can find 4-6 idiots(potential customers) to volunteer as MWT testers. I volunteer to be the first idiot in the sample group and I will bring my Titanic DHE barrels previously deemed “thin” as a test subject . Perhaps after I am done with my blind test with the Hosford gauge and I find it idiot proof I might be convinced to buy his tool to prove I am not an idiot. Until then I will measure the bore diameter of every gun I own and make my shooting decisions based on MY results.
Patrick
PS I was not happy when the jackass brought my perfectly good factory barrels back and declared them thin.

Patrick,
Its a little early in the am but who are you calling idiots ?

Patrick,

I own the Hofford barrel wall thickness tool. If operated correctly it will provide exact measurements time after time. If operated contrary to instructions it can provide inaccurate measurements. I believe those are usually larger than actual thickness.

Have you considered the buyer may have trying to make the barrels seem thin to reduce your sale price substantially? Little did know that just behind your friendly smile is a US Marine which when challenged, eliminates enemy though fire and maneuver. Or in that case, surely a glare from your eyes as sharp as a eagle focusing on ripping off a rabbits head! When caught off guard I instantly do the same. :).

I think the bozo was simple a shister.

Mark

I did not mean to thank Patrick, touchscreen. I do understand his feelings though. Seems everybodys an expert and they want u to know it. Humbleness theres a quality i enjoy. Best ch

Patrick, one person's "thin" is another person's "safe to shoot."
Precise wall thickness measurements is the only thing we can base our opinions on, not someone else's declaration of "thin" and "not safe to shoot." At .730" and original finish , I would shoot your barrels sight unseen.





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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.

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.

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

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 !

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





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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

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 :eek: a very expensive mistake on my part:banghead: so it can pay for it's self in one use !

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

That would make perfect sense Rick.





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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.

I have never had much interest in barrel wall gauges because I believe for the most part, but there exceptions for sure, that if the bores measure spot on or very close to factory bore diameter specs for a specific gauge, then I assume the barrel wall thickness is safe.

Bill

One might get away with this philosophy in regard to American built guns like the Parker, Fox, L. C. Smith, etc.

Their barrels generally run a bit "thick" to begin with. Thus a hone or two might not be dangerous.

However, do NOT count on this approach with British or European guns. Especially those from the 19th or 20th centuries. Their barrels were often turned to a thinner overall wall thickness/contour to begin with. Thus, a bore gauge might suggest "OK" after honing, but the actual wall thickness could well be below safe limits.

It is also important to know where a barrel might be thin. Anything odd within the first 18 inches is vital to know about.

To paraphrase Gen. Douglas MacArthur, "there is no substitute for wall thickness."

Nice of the Belgians to tell us exactly the bore and muzzle constriction, weight of the barrels at time of proof, and load (only 1897-1903) for which the gun was designed.

12g Manufacture Liegeoise likely proved with Mullerite for a service load of 2.70 grams = 41.67 grains = 3 Dr. Eq. (42 grains) "E.C." No. 1 or "Schultze" with 36 grams = 1 1/4 oz. shot.
Note bore 22 cm from breech was 18.2 mm = .716". After WWI bores were generally 18.4 = .724"; honed to .729" would only be a loss of .0025" of barrel wall IF perfectly concentric.
If originally .716" and honed to .730" would be loss of .007" barrel wall.

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[QUOTE=John Campbell;205811]One might get away with this philosophy in regard to American built guns like the Parker, Fox, L. C. Smith, etc.

Their barrels generally run a bit "thick" to begin with. Thus a hone or two might not be dangerous.

However, do NOT count on this approach with British or European guns. Especially those from the 19th or 20th centuries. Their barrels were often turned to a thinner overall wall thickness/contour to begin with. Thus, a bore gauge might suggest "OK" after honing, but the actual wall thickness could well be below safe limits.

It is also important to know where a barrel might be thin. Anything odd within the first 18 inches is vital to know about.

To paraphrase Gen. Douglas MacArthur, "there is no substitute for wall thickness."[/QUOTE

Good point to remember, but for me personally, I have never even looked at a British gun, let alone have any desire to own one.

Bill

This may work very much against you because bore diameters varied greatly from early lifter guns and even later.
.729" may be considered the standard for 12 gauge but I know guns which measure over .750" and have never been touched.
You may err on the side of caution, and pass on a lovely gun that measures .740", assuming it had been honed eleven thous, you will loose out.

I made my own and it works well
 

Mr. Anderson is being very trusting of "factory bore diameters", which may vary by about .030 from gun to gun. I personally don't care if gun buyers measure bore diameters and wall thickness, but I will continue to do it after 56 years of paying cash for double barrel shotguns. My equipment cost me about $300, has been working for decades, and has protected me through hundreds of thousands of dollars of potential mistakes. A selling dealer who tells you he doesn't own a bore gauge is a liar. He just won't let you see him using it.

thank you Mark, you made me laugh.

Patrick

Not necessarily, if I know the bore diameter of a certain era of manufacturing states a bore of .750, then my bore gauge will confirm this for me. I said that I do not have much use for a "wall thickness" gauge if I know the bore diameter of the manufacturer at differernt points in production history, such as the lifter gun you mentioned. If I am looking at an American 20 gauge shotgun, for example, and find the bore between .612 and say .618 or .619, and I know they don't vary by .030, I see no use in a wall gauge if no pitting exists. Besides, I wouldn't own pitted guns in the first place. And if I believe I am looking a special "back bored" barrel I can always measure the inside of the bore and outside barrel diameter to give me a general wall thickness. True, not as thorough and complete as a top end wall gauge, but close enough to assess the safety of the barrels. And my collecting is but a couple, few guns a year so my methods will prevail.

Bill

Why myself of course. I think I clearly volunteered to be the first "idiot" to sign up for MWT training at the Vegas show if offered. I do this knowing that if given a precision measuring device I will either break it, “uncalibrated it” or consistently get different results measuring the same subject multiple times. If others have this same aptitude with these types of tools and object to my classification of their skill set then I sincerely apologize.

I previously had a MWT gauge from Brownell’s and I followed the directions sent with the gauge and could not make the gauge work. I then turned to the internet for some "enhanced" instructions and found a variety of solutions to using the Brownell’s gauge. I settled on the following set of instructions to get the most accurate results;

1. Make sure you are facing due north so that you are magnetically aligned with the earth to decrease the variance of measurements.
2. Suspend barrels from a floor joist in your basement to decrease anomalies in measurements. Use a joist at least 6 feet from an external wall.
3. Make sure humidity in basement is less than 28.5%
4. Enlist two additional helpers to secure barrels for test
a. One helper to hold the barrels
b. One helper to hold the first helper in place
5. Measurer will lift right leg and point due north to also be magnetically aligned with barrels(ok, I made this one up)
6. Insert measuring device into barrels and drag along barrel wall remaining PRECISELY level to get the most accurate measurements.


When my wife came downstairs and found the barrels hanging from the joist and George holding the barrels and Bill holding George and me trying to work the PRECISION measuring device she just shook her head and said “why don’t you just measure the bore dumbass! ” So, I sold the Brownells gauge and have followed the experts advice every since. :)

Patrick

simple the best, I made one my self, but standing vertical this way force of gravity don't influence arm and then gauge

simple is best

Just to make things interesting (and not start a war) I have taken the ribs of of several barrels as I am sure many members have and Have found them to be heavily rusted. So the conclusion that I would make is that the thinnest part of the barrel is going to be where you can't measure. That would be under the rib. Stating barrel wall thickness may be ok but I will proof fire mine.

true

but that's a you break it - you bought it deal

if you know the barrels measure thin before purchase - that expense is avoided

I might just be lucky but...Most of the ribs I have removed,were full of nasty looking flux but rust has not been a issue.
The area where the rib sits is filed to a slight flat and is thinner on most of the barrels I see



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Neat Gary; another Damascus-Twist barrel.
This is David Purnell's 1888 12g 0 grade toplever hammer gun refinished by Dale Edmonds.

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Gary Carmichael's also marked "Twist"

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