The Crown may get $400 for the first few hundred but by the time #19,000 is sold it will be part of a large lot (individual sales having run their course) and they would be lucky to $50 per pistol.
As a collector, I could care less about DND destroying these. The law of supply & demand doesn't count when the guns on the supply side are unavailable to the demand side so the destruction will have no effect on current values. Further, the pistols in DND possession are, for the most part, multiples of the same variants so of little interest to the average collector.
Nobody should be surprised at DND's stance. Trudeau, during his tenure, established a policy of not selling small arms on the open market. This announcement of smelting the surplus pistols is in line with that policy.
Terry, I like your idea of a HP shoot. I have about 40 in the safe and can find a decent shooter if pressed.
