Help - Wall Thickness at the Muzzle ?

[jay shachter]

Hey Guys,

Regarding barrel wall thickness, I have measured literally thousands of them. If you are using 25 thou as your minimum, you will be retiring most of your 20ga. Parkers and "O" frame 16ga. Parkers, as well as many of your other fine lightweight doubles. Most light weight Parker 16's and 20's range between 20 and 25 thou as their minimum, usually 6-12"
back from the muzzle. I am talking factory original, unmolested, original blue and factory bore diameter barrels. I have measured a half dozen Parker ORIGINAL barrels that got down to 18 thou in the same areas, and they were not honed or reblued.

If you look at the Shooting Sportsman from last fall I believe, they had an article addressing concentricity in barrels. The article was mostly about Holland and Holland and their quest for perfection in barrel making. The first few paragraphs asks the question; how to quantify what constitutes a safe barrel when buying vintage guns? The stated industry standard as mentioned in that article is 20 thou, not 25. It is important to clarify that this measurement should be beyond the mid point of the barrel set.

In all the measuring I have done, there has never been an American made double that had barrels with concentric boring. They all are signifcantly thicker on one side of the barrel than the other. The thinnest point is usually found in about an area that would constitute 1/8 of the total circumference of the barrel and in a 8-10" longitudinal line. The rest of the barrels are substantially over the minimums.

Just an FYI