Based on my attempts to break a Rock Chucker getting steel-coated Horny's to pass thru a mere 3-4 thousandths of smaller hole, this seems like a good idea.

My questions about it have always including a wondering about the ACTUAL dimensions of the barrel, both groove and land vis a vis the bullet. I mean, from what I've read, the internal bore/groove diameters can be all over the map on old British guns, so I suppose one could run into a combination of bullet diameter, hardness and barrel specs that would result in trouble, whereas other guns being shot with the exact same bullet may exhibit no damage at all, tho I still don't see how a mono bullet could create an evenly distributed expansion of the barrel to produce the tell-tale shadow lines for all the reasons we discussed in the past.

Another thing I've often wondered about is the actual reduction in barrel wall thickness that might occur on a gun that has seen numerous rebluings, with barrel striking before bluing reducing the wall thickness over time to a dimension susceptible to stretching. Is THAT the cause of the elusive OSR?

It seems like all these theories were fronted with no proof ever being found of what combination of dimensions, jacket/type of bullet or modification of barrel ever being found that DEFINITIVELY proved the cause {-es} of "OSR".

Thus the generic "Don't use monos" approach, which when one is dealing with guns of the values represented with many of the old Brit doubles, certainly is understandable.