Um, nope, the wad jams against he sides of the hull as the tapered diameter reduces and stops leaving a HUGE chamber below the gas seal, and using more pressure in an attempt to get it to go deeper just folds the WAA 12L wad legs pushing the cup and slug deeper but leaving the gas seal were it jams, and I'd need much more powder to fill that chamber.
And I am following the manual as far as hull, wad, powder, primer and projectile are concerned.