doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Wall thickness question, again please

How low is too low? I have the chance to get a deal on a Holland that is told to me that has 20th in one barrel. Not just a spot but a length near the muzzle end.
Advice needed

I would say it’s a deal because the barrel wall is thin. How far from muzzle end does it become 20 thou? I have a 16 gauge H&H that is 19 thou towards the end of the barrel and hunt with it regularly. I use RST loads and I’m not worried about the pressure. The problem becomes removing a dent or reblacking the barrel.

Ken

If it’s Damascus I would want to know thickness at forcing cone, in front of cone, 6in from breech, 9in and 12in. Don’t care much past that.

No matter the steel, IMHO the critical number is at the end of the chamber.
This is my scribbled upon chart from CIP (in mm), and you'll note, because the angle of the cone is sharper than the taper of the exterior of the barrel, the cone WT is usually the same or greater than the end of the chamber.
Otherwise I'm with JT

Also note Category 1 “Standard Steel” (Non-alloy AISI 1045) with tensile strength = 101,526-123,137 psi would fit the industry standards for 4140 Chrome Moly & 4340 Chrome Moly Nickel - both are “low alloy” steel. Vintage doubles may be AISI 1030 or 1035 with a tensile strength 85 - 90,000 psi, with Krupp and Winchester Nickel Steel, Poldi Antikorro, Böhler Antinit on higher grade guns, with a tensile strength of Category 1.
Pattern welded barrels average about 55,000 psi so I would favor greater MWT.



We have lots of measurements of believed to be original barrels in which the distal 1/3 is about .020". Don't worry, be happy

90 and 30 or bust...

more or less...

so to speak...

Like the others said

If its toward the end of the. Barrel not so bad
But what is it in front of the chamber and maybe and inch or so down

Ever think maybe that's why its a deal as you said?

What the rest of the wall thickness.

John

Arrieta

Information coming from the guy is the wall thickness is light. When I pressed I got that it was 20th down on one barrel near the muzzle

I had one with .020 and .018 both about 5 inches from the end of the barrel on a Parker with Damascus barrels. Gun was a 16 gauge. Crossed Chisels measured it and said shoot RST and you will be fine. It had not been honed. It was struck that thin in 1898. Sold it to Mr. Weber several years ago. PS. I have shot many Foxes with .025 about 8" from the barrel ends. They were original 4 weight barrels and had not be hones. Its like real estate. Its all about location, location, location.

And price point.

Even with the thinner tubes, it will likely outlast you and even the next guy. Only use good shells (such as RSTs) and keep it clean.

Good discussion of wall thickness and proof generally here:

https://www.vintageguns.co.uk/magazine/is-that-gun-in-proof-

Thanks Dan, I read the article