Greg, I don't know what the "minimum" is but I agree many of our guns are much thinner than we'd like to think. Or, perhaps we'd rather not think about it at all--out of sight, out of mind. And it's sure not limited to English guns. I shoot a couple of Parkers and Lefevers with original bores and outside that appear to be stout in all respects. However, when the truth gauge (wall thickness) is run in it gets scary. Both of the damascus Parkers I'm thinking of are about .090 in front of the chambers and the Lefevers are around .025 a foot in front of the breech. But, you know, they've handled about every type of ammunition over the past 100 years and continue banging away today (with low pressure loads). So, I say go ahead and enjoy your guns but don't feed them Wally World bullets.
