doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Question on Wall Thickness Gage

Berrien, thanks for the links.
I am trying to figure out what eightbore said about the rope holding the gage. Isn't the ring good enough or has someone come up with the rope as something better. Maybe that is for the Manson gage because I thought he said it was $100, this one is 4x that with just the one rod.

I installed an eye hook at the end of the Manson gauge opposite the micrometer. I put a short looped piece of rope through the ring for more control. Letting the block hang from the rope keeps everything vertical. I am not referring to the "ring" on the back of the micrometer. The micrometer hangs at the bottom of the barrel surface being measured and the "ring" on the micrometer is not used for anything.

Got it, thanks Bill.

Altho your conversion came at the feet of Hosford, Bill, I see little to distinguish your horizontal application of the gauge and A-Mike's orientation and manipulation of his "Truth" gauge. As long as it works. PeteM has found another Achilles heel on David's: the inability to measure the walls of the chamber. The sliding indy holder also seems to be the idee fixe without which nothing is possible and with which less is possible without additional fixturing and special cases. I can see Dave riding the big tool carriage on the armature lathe at the power plant. Hey, Dave, I think direct-measuring at a single point with a caliper (the Manson design) is still the way to go. If I were "improving" the thing, I'd think about a more rigid external indy carrier arm( el-shaped casting, iron pipe, carbon fiber tube).

jack

Jack, Pete or anyone, do you feel it is important to measure chamber wall thickness?
I can see if looking at a gun and the barrels are below the standing breech, then a measurement would be needed. Or if you felt the chamber was opened for some reason.
I myself use telescoping gages to check this if there might be a problem.

The only reason I could see measuring chamber wall thickness is if the chambers were lengthened.

Yeh, I think a severe restriking of the barrel exteriors in the chamber area and/or lengthened chambers would make w/t important in that area. And I don't know that I'd rely on a chamber diameter measurement made with a T-gauge and subtracted from barrel OD at the corresponding external location divided by 2 to give me the wall thickness. You gotta watch those barrels where the breeches are shy of the balls!!

jack

David,

You are assuming you can see the tooling marks. I routinely check the chamber wall thickness on all guns.

Go to Google/patents and type in "mouse trap". You will get 11,300 hits. This forum is a good place to vet ideas, research, design concepts, etc. We all learn through the process. Keep up the good work. This gauge is a nice effort.

Pete

Thanks guys for the reply. I never really gave the chamber area much thinking aside of what I mentioned.

Has anyone had much experience with the Hosford gauge?

You can do a decent job measuring the chamber wall thickness with a portable two finger gauge. They reach in 6" or so.

Builder,

I have used the Hosford gauge for about a year, and I find that I get very repeatable measurements. I have no �gold standard� barrel to which to compare, but the consistent repeatability gives me some confidence.

I think your comment on using an alternative approach (two finger gauge) for measuring the wall thickness of the chambers makes eminent sense.

Finally, I am always in awe of the creativity of creating new ways of advancing the craft. Congratulations to David.

Berrien