From the 16ga. reloading group:
Cheddite/Imperial 2 ¾” 6 pt. 1 oz. SR-7625 21.5 Win. 209 SG-16 1154 7300 Armbrust Pressure/Velocity Tests 3-31-03 Nice consistent load. Little deviation.
Cheddite/Imperial 2 ¾” 6 pt. 1 oz. SR-7625 23.0 Cheddite 209 SG-16 1237 8633 Armbrust Pressure/Velocity Tests 3-31-03
I bought the Canadian Cheddite hulls preprimed with the Cheddite primer, loaded once, loaded subsequently with the W209 but with the 1 1/2 gr. less powder. I don't get any suggestion from the chart that the primers can be directly substituted in the same loading but perhaps I haven't been paying attention.
jack