doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com brownells barrel thickness gauge

Amen to the Galazan gauge, that's what you need for quick accuracy.

Incidentally, Monty, when you started rattling off prices in which you'd buy or sell guns and you lacked a proper gauge, I was thinking you were destined to be burned or burn someone else (no malice intended). It sucks to drop $1000 on tools but before I ever bought a vintage gun (and especially before I sold one I didn't want any longer) I made sure I had all my tools.

Buy:

A skeets universal bore gauge $200
A galazan wall gauge $550
A full turnscrew set $200
A chamber gauge $35

Every time I get a gun I blueprint every inch of the barrels and determine whether it is in proof and whether it as been reproofed. It tells volumes on the life of the gun.

Rookhawk has the right attitude, except that the Manson gauge will do everything the Galazan gauge will do for $450 less, and proof is bullshit.

Rook Hawk I couldn't agree with you more but as I said I am cheap. I own a bore gauge I think I paid $100 a few years back and the brownells I think I paid $100 for the fun. Being inexperienced as I am I usually rely on other people who have had the experience meaning expert gunsmiths.Which to me is more valuable than the tools.If you are not a gunsmith and most of these guys probably not be qualified to me to be an expert or give what I would call an expert opinion.But as I said I value every opinion out there yours included.I can assure you I don't care how many tools you have you cannot measure exsperience.
By the way I have sold several guns on this site I will give them two weeks to decide or take it to a gunsmith if they don't like it I'll give a full refund even if they can't find anything wrong.
I talked to Curt Marrington again today and he said he has had guns that measured .010 thickness near the muzzel end to proof.
Kirk said the problem is with dents.

RookHawk I am with you I might pass if the Holland is only .025 near the forcing cone.I'll get Curt to look at it first.

Recently bought a Manson gauge, to measure wall thickness in a 20 gauge Birmingham boxlock. In order to have some assurance that I'm using it correctly, and getting accurate results, I intend to practice on a junked barrel the local gun shop owner was kind enough to give me. My plan is to take measurements in the horizontal position. and then cut the junk barrel with a Metabo cut off tool, either wedges cut out opposite each measuring point, or a strip cut out along the whole length of the barrel, thereby gaining access for a machinist friend to use his micrometer to take direct measurements. And then compare those with the measurements I got with the Manson gauge. Anyone have any ideas on how to improve on this procedure?

"And then compare those with the measurements I got with the Manson gauge. Anyone have any ideas on how to improve on this procedure?"

When I take wall thickness readings, I take them in 4" increments along the barrel. The Galazan type I made is a copy of one a friend has. I can measure close to 16" and then flip the barrels end for end and read the other length providing the chokes are not too full in a 12 gauge. Meaning if the muzzle end is .690 I cannot fit it over the rod. Once it is centered on the bottom brass cone, I pivot the barrel on the brass cone that is locked on the shaft from top rib to bottom rib and read the wall thickness and record the readings from lowest to highest. I then move the brass cone down another 4" and do the same until I get to where I left off from the other half.
Most of the time, the readings vary as the barrels are not concentric as most are not.

Beagle, that is a good way to prove that you are using your Manson Gage right, but you have to read the barrels as I stated and write down the areas where the readings were taken to compare them to the micrometer readings. In order to measure them with a micrometer, you will have to use a ball micrometer, or better yet a pin one to get accurate readings as a flat anvil micrometer will not give you accurate readings.

Please let us know what your results were. Also if these barrels have pitting in areas, measure some of the pits to see how deep they go.

Beagle
That sounds like a good Idea to me although my micrometer is flat not a ball but that can't be too far off I'll have to try that on the muzzel end to see.I am going to get someone to put a leaf spring on the back of mine to hold it snug against the barrel.

You can purchase a ball attachment for an ordinary flat anvil micrometer. Pretty sure the one I have has a diameter of .200" & has a collar to center it over the anvil. You can simply run the spindle down against it to verify the reading. Measure a few bbls at points you can each with the micrometer & then with the wall thickness gauge to confirm. If its accurate at one point, then as long as you make certain you don't lket the shaft of the WT gage hit the side of the bbl it will be accurate at any point. This same caveat applies equally even if you cut up a bbl. There is however no real need to go to the trouble of cutting up a bbl, even a useless one, to prove it. You are of course goint to need either the ball mic or attachment either way so nothing extra required.

Monty, "That sounds like a good Idea to me although my micrometer is flat not a ball but that can't be too far off..."

Yes it will, your flat anvil will only be touching two sides and not letting it get to the bottom. It could be as much as .015 or more.

Thanks for the advice on micrometers. This is a new area for me, I was not even aware there were different types of micrometer. I will post the results when the project is complete.

How do you used the manson horizontally? I can see how it might work vertically but it would seem moving the instrument horizontally would cause it to tilt. More instructions and more detail please.