doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Measuring barrel wall thickness

$95.00 for a wall thickness gauge. The bore micrometer and the vernier caliper or micrometer used to measure the "difference" would cost you that much or more. The $95.00 wall thickness gauge would also give you the true measurement. Sorry, Pooch, you're no machinist.

The $95 gauge from Brownells is a joke.

A $500 galazan gauge or hosford gauge is not, however.

A real gauge gives real measurements. I would not be interested in owning a gun measured using the Pooch method. The odds of misrepresentation are too high.

Only a real wall gauge is going to measure accurately at the depths necessary to know a gun is safe. A .015" reading at the muzzle of a cylinder bore is irrelevant to safety, a .030" guesstimate 10" from the breech is not trivial.

Get the right tool for the job.

to be safe and sure, take your barrels to an old time smith who has the tools and experience to do the job.

I agree with Rookhawk. The Hosford gauge is the way to go, but one has to understand the data it generates. It is real good for measuring the depth of pits too. Pooch, I see in your biography you work for Cabelas. Surely, as many English guns and others going through Cabelas, they have a gauge. If not, you should be able to talk them in to buying one. They are a very useful tool and pretty easy to use. I wouldn't buy a vintage gun without measuring up the barrels. It is clearly the smart thing to do when contemplating a purchase of any old gun.

They have been pretty lucky so far. But the decisions come down from Corporate where there are no engineers and my voice is not big enough to reach Corporate. We were sent the $95 special for wall thickness, which does more harm than good. The Hosford is a decent instrument but it's still not checking the wall thickness beneath the ribs. The best of the mechanical measuring devices are still a bit dodgy because of the difficulty controlling the tension on the support rods.

Ultrasonics are used on turbine blades and barrels can suffer a similar abuse, just not as extensive. The Chinese are producing some pretty cheap ultrasonic testers, maybe that will be a future tool for gun barrel wall thickness.

Nah, cabelas is blissfully ignorant. I bought a Ferlach from them and it had 2.75" chambers.

I measured it in there store when it got shipped in and it measured .015" minimum walls for quite a length of the gun. It had been shot with steel and someone tried to hone out huge flaws.

I showed the Cabelas management the issues and demanded my money back. I also demanded they disclose the deadly flaw in the gun to all customers. They said "yeah, sure". 3 months later it was back on their website and then sold to an unsuspecting victim.

Cabelas does not measure, nor do they pay a premium for good walls on guns. Every dodgy gun in the country gets pawned off on them.

This is my take-off of the Galazan gage. I can measure 10 and 12 ga. on one rod and 16 and 20 ga. on the other. In 12 ga. with very tight choke around .690 I cannot put it muzzle down as it will not fit over the rod with the ball. I can measure 15 1/2" from breech end.
I put a level on mine mainly for 10 ga heavy wall barrels in doing muzzle end with all the weight now up, especially in the first few readings.

[
In my opinion, to use the Hosford type gage, you really have to know what you are doing in measureing the breech end because of the weight on the bar. It would have to be measured more than once to get the right feel.

If I wanted to change the digital dial out to a Starrett, I could use a variety of tips and one is a needle tip if I wanted to get that critical next to both ribs.

I don't know how reliable a micrometer would be on the outside in combination with a dial bore gage.

I forgot to mention on doing 10 ga barrels with the muzzle down. The aluminum gage in the box is a 10 ga chamber gage with a spirit level mounted in it. When the base is level and the barrels are mounted and the muzzle end is in the tapered collar (brass) then I insert the chamber spirit level and then measure from top rib to bottom rib usually in 3-4" increments. Takes a while but then I know what I have.

We have collected a bunch of junk. They came and got me to help in this area, but without the right tools and without everyone using them I don't think much is going to change.

I've been trying to design something using a laser and a mirror to align things but I think the ultra sound will be the system of the future.

JDW how do you set your zero? Do you secure the barrel at both top and bottom?