RR, the difference between shooting long factory shells in short factory chambers and doing it in lengthened chambers is that at least in the first case, metal hasn't been removed--which process cannot possibly make the gun stronger.
Larry, that's obvious, I didn't state anything to the contrary.
I have a 1939 Nimrod drilling that has 70mm chambers but is not stamped as such. I had the gun checked thoroughly, was told it had no damage. I only shoot 2-1/2" in it to keep it that way. I have no idea how much the gun was shot after the chambers were lengthened (my guess is not much at all) or what shells were used. Very few buyers can be sure what a gun in question was fed before they owned it. My point being that just because a gun has lengthened chambers , by and of itself, is not a reason to condemn it. What needs to be taken into account is the result of actually being shot and what was shot.
Now, how chamber length originality affects collector value and price is another story. If they're not original I use it every chance I get to lower the price on a gun I'm buying. If they are original it's definitely a point to bring up if I'm selling.
