I've had a first gen P85 for about 20 years now, and it's always digested everything I've fed it. The list includes:
- American Eagle
- Federal HydraShok
- Glaser Safety Slugs
- Cheap range ammo
- Etc., etc.
I'm using the stock magazines, and just last month replaced the springs in the mags and the recoil spring. In probably 5,000 rounds through the gun, I've never had a misfire, FTF or FTE.
I'm not familiar with the mag you referenced, but could it be that the mag spring is not stiff enough? Have you ever had an issue with the Ruger mags?
If you bought the gun used (or if you've put a lot of rounds through it), you may need to replace the recoil spring. Wolff makes a package with the recoil spring and the firing pin spring, and the kit is only $8.00 or so.
If it were me, I'd start with replacing the mag springs and recoil springs, then head back to the range. I seriously doubt that the WWB ammo is causing any trouble.