Barrel wall thickness - a new toy!
 

Having heard various stories about thinned walled "reworked" guns I decided to purchase a barrel thickness guage. Bought the one from Brownells, and with a little practice quite satisfied.
In any event it has yielded some interesting data I thought I would share. For ease I will leave the 0 off the front of the numbers. I have measured starting from muzzle then at 4, 8, 12, 16" back. I then measured starting at the chamber - 4" in, then 8, 12, 16

First gun - a 12ga. GH w/28" Damascus - 2 3/4" chambers (I was surprised by that). IC & M -This gun was in very good condition metal wise, stock badly abused, now repaired.
L - 50, 35, 41, 40, 42
R - 45, 42, 36, 35, 36 , interesting it seems the tighter choke barrel (L) is bored tighter all the way through.
CL - 110, 58, 40
R - 113, 56, 38

Second gun - a 12ga. VH w/30" fluid steel - 2 7/8" chambers. M & F/M - This gun was a train wreck, with a crack in the left barrel about 7" back from the muzzle at a large dent. Major repair on it, with many new action parts, sear springs, etc. Restock. A family heirloom, 3 generations. The bores had been "polished" so I was actually concerned. But there is still much metal left.
L - 52, 36, 35, 33, 29 - at the location of the repaired crack it was 23
R - 48, 41, 33, 33, 32
CL - 104, 59, 40
R - 110, 66, 40

Third gun - 16ga. VH w/28" fluid steel- 2 1/2" chambers. IC & M. A recent aqquisition, and the barrels look like they have been polished, but not abused.
L - 35, 28, 28, 30, 30
R - 25, 30, 27, 30, 32
CL - 92, 43, 30, 28
R - 108, 49, 39, 30

So what can we might conclude - in another string on the site, someone was referencing 20 thou as a suggested minimum. That would suggest a gun that has had a lot of bore work, or outside polishing or both. Even with the different barrel make up and spread of age of the first two guns, the wall thickness hasn't changed much. I should have mentioned they both were size 2 frames. With the 16ga. having 2 1/2" chambers, is there enough metal ahead of the chambers to lengthen them to 2 3/4". Further study is in order on that one I think.

Hope this hasn't been too dry, but nothing like a little actual measurement when considering a subject like this. :):):):)

I wouldn't jump to the conclusion that a gun with .020" barrel wall thickness has had a lot of bore work - not necessarily so. Some guns might well have been finished that way from the factory if they were filed to be lightweight guns. We have seen such guns but they are not common by any means. Caution is key on guns that have these kinds of minimal wall thickness.

I would be concerned with the VH that has 2 7/8" chambers.

Does CL mean Chamber Length?

Dean,
it is 2 5/8", so I think it is ok.

The C was my way to note they were the measurements taken from the chamber end. The first measurement is 4" into the barrel from the chamber end.

Okay Keavin, so that 2 7/8" was a typo.

The critical measurement at the breech end of the barrels isn't so much at the 4" mark but rather at the precise juncture of where the chamber enters the forcing cone. Generally, that is where the barrel walls will be thinnest in the rear 10" or so.

Dean,
yes a typo. Ok, we will take a look at that location and see what they measure. But what should they measure?
I have a GH that I bought for parts, that was sleeved down from a 10ga to 12ga. The right barrel failed with the blow out starting right at the sleeve joint (at the end of the chamber) and peeling a strip out of the barrel for about 2'. Don't know the history, maybe a plugged barrel, ???? But it definitely makes an impression.

I think I've read that .090" at that juncture is about the minimum acceptable thickness for a 12 ga. gun. But please do some research on your own on that - please don't take my word as final.

Barrel wall thickness
 

Keavin: The attached show measurements on some of mine. Do not know if they are within minimum but I use them all with RST shells. Bob

Thank you Bob.
Lots of information here
http://parkerguns.org/pages/faq/BarrelThickness.htm
http://parkerguns.org/forums/showthread.php?t=1565

Thanks Bob.