I have Lyman manuals #37 (2-50) & #38 (Jan 51). Neither of these manuals list any Alcan powders at all. A Lyman manual I purchased new back around '57 has lost portions of its front pages & cover over the years, but I think was maybe 41, just not sure now, has only Al-5 & AL-7 listed. Powder charges from this manual are close to those given for the AL-6, "BUT" only with 1¼oz shot charges in both 10 & 12 gauges. Heavier shot wts in this later manual were for AL-7, but also with heavier powder wts. It might seem that the AL-6 was for the heavy shot wts, but not suitable for full velocities that were obtainable with AL-7. I do seem to recall AL-8 being introduced in the late 50's prior to the introduction of Remington's first plastic loads in the SP (Steel/Polyethylene) cases around the early 60's. I believe this was the firsat venture into plastics by a Major Ammunition Co on a production basis. Herter's had offered some plastic cases for loading prior to this, made of a harder plastic which used a top wad & were to be slightly turned in to hold the wad, not a full roll crimp as such. I tried a few of these but they were prone to splitting at the mouth after a couple of loadings & no longer held the top wad reliably, so not very successful.
