Paper Hull Imperial Slug Age?

[hbar2]

Does anyone have an idea when Imperial would have ceased production of 12 gauge slugs in paper hulls? I cannot find anything definitive online. Thanks a lot

 

[Ganderite]

Early 60's, I think

 

[badgreenbird]

I would have figured early 70's

There are some CIL experts on here, hopefully they will chime in

 

[hbar2]

I put my money on it being 60s vintage. Headstamp is "Imperial-12-Canada". It turned up somewhere it never should have been, so I am hoping to get a rough age so I can drive a point home......

 

[nowarningshot]

Take look out your window...older than the hills, younger than the mountain,