Barrel wall thickness

[OLD GEEZER]

Jay: I thank you for a very informative response to my question. I for one wish you would chime in more often. I have learned alot in the time that I have been a PGCA member and having your knowledge is very helpful.Thanks Thomas L. Benson Sr.

[jay shachter]

Thanks everyone for the encouragement. And Dean, I did mean from the breech, not the muzzle. It was Sherman Bell's article, likely in the DGJ. I will do a search as it is something I need for my customers and friends alike. By the way, most are one and the same.

[jay shachter]

Bill M.

Tell me about the Manson gauge, and where can I see one? The problem I had with less expensive gauges was the ability to use them in the field and measure all the way rib to rib. I would like to see if this one would be useful outside the shop.

The reason I like the Hosford gauge compared to the big desk top gauge I had like Galazan sells, or the $150 gauge that I bought from Brownells, is that it is both portable and accurate. 4 different people could use a big desk top gauge we have all seen somewhere, and depending if they tilt the barrel or not, would likely come up with meaningful differences in measurement. Likewise, the only way I could get the little Brownells gauge to be consistent and usable was to hang it stationary from the ceiling and bring the barrels up from below. It was very touchy and difficult to get a good reading.

The Hosford gauge is simple and repeatable, and very portable. With 5 minutes of instruction and practice, 10 out of 10 would get the same measurement within a thou or so.

I hope the Manton is different, as I would like to have another tool!

Thanks again,

The Brow

[OH Osthaus]

the Manson gauge

http://www.brownells.com/.aspx/pid=2...HICKNESS-GAUGE

there is a brace that is not shown in the picture that prevents twist

I have practised with it in several modes until I know I can get consistant measurements in different settings.

along with a Skeets bore gauge, a scale, a tape and a caliper (not in the pic) you have a compact set of tools that will give you some level of confidence when you consider a gun.

[Dean Romig]

Originally Posted by jay shachter

Hello Guys,

Unless you are shooting guns with obstructions in the barrels, there is no measurable risk shooting reasonable loads in guns with 20 thou wall thickness at least 15" from the muzzle, provided all other issues are sound, like tight ribs, no serious dents, etc. This is not opinion, but data collected for decades under controlled testing.

From the muzzle Jay or did you mean from the breech?

Thanks for the very knowledgable post. Information like yours is very valuable for everyone who shoots these old doubles.

Was the curve you are referring to printed in Parker Pages or on the forum here someplace?

Dean

[Drew Hause]

This? By DuPont in the mid-30s

[Bill Murphy]

I believe that Sherman Bell may have done the "inch by inch" pressure graph for black and smokeless loads. I don't know which one of his articles may have included this information.

[John D.]

Originally Posted by jay shachter

Hello Guys,

I don't chime in on these conversations often,...Sorry for the long post. It is my reason for not writing. I can't say things in a few words while typing!

Jay, I really wish you WOULD chime in more often - excellent post - thank you..!

As a few of you know - I've been following this thread closely for a while, but more recently - hanging on every word for personal reasons. You see...

Recently I put up my DH 20 DAM Parker Show gun for sale (click here if you are a PGCA Member) and the potential buyer asked me what the barrel wall thickness was? I told him, honestly - I'd never had it checked - and after firing hundreds of RST and my own low pressure rounds through it - never thought to? So, Monday - I did..

To Jay's point about light barrels small bores that left the factory that way, I would agree. Well said! You see, this 26" DAM had an UNSTRUCK weight of 3 pounds exactly (no ounces stamped). Today - after striking and whoever refinished them - they weigh in at exactly 2 lbs - 8.2 ozs, a difference of only 3.8 ozs..

Now - on to the other measurements - bore size (L) is .618 and .619 (R) with constrictions of 0.16 (L) and 0.11 (R). The barrel wall thickness is 0.019 (L) and 0.015 (R) - BUT those are 7.75" from the MUZZLE, not the BREECH..??

So, anyway - I'm wrestling a bit with what to do with this little DH beauty based both on this thread and the collective wisdom posted in this thread regarding wall thickness... Leave it, TIG sleeve, shoot it with removable 28GA tubes - leave the original BBLS as is, etc...???

Hope this helps with the data from my little DH bbls..

John

[Smoothebore]

Sorry to tell you, John, but there are 12 inches in a foot, but 16 ounces in a pound. Your difference is 7.8 ounces.

Dave

[John D.]

Originally Posted by Dave Purnell

Sorry to tell you, John, but there are 12 inches in a foot, but 16 ounces in a pound. Your difference is 7.8 ounces.

Dave

Thanks Dave!! That's OK - I also messed up the MUZZLE and BREECH, and had to go in and correct that as well..??!! I should learn to type less - or proof read longer

Best to you - and thanks again!

John