Many thanks Schuetzendave for your fine reply and tutorial. I don't profess to have the ultimate experience in bench shooting skills, but I keep working at it. I purposely made a bench stock for the CPA, and it does help over the schuetzen style. I do very much like the CPA rifle.
Your advice on the both the bullet alloy, and powder charge are well taken, and I will try both starting this week.
I use Paul's plugged case as my breech seater, but with a harder alloy that may prove to be problematic. A seater where the bullet is directely held by the case, and then inserted into the barrel I would think is the best of all worlds to eliminate concentricity of seating errors. That I will have to look into more closely.
I have tried using cork, foam, and PVC (all .062" thk) as wads, but only at the case mouth to keep from dumping powder into the action.
My findings are that they all work for the purpose intended, and didn't bring much to the accuracy equation. Except for the PVC, which may afford protection of the bullet base at higher velocities. The other two disentigrate upon firing. I use no filler of any kind.
As far as lube, I find that it is very important for consistant accuracy, and that SPG and Improved Emmerets are both good in that department. Alox and others did not fare well at all.
I'll keep you posted with results of alloy and powder charges.