I use a 14lb recoil spring in my Para P16. If the case falls more than 10 feet away I'd use a heavier recoil spring. If the case falls within two feet I'd go lighter.
G-Man Have you checked the dot module for movement/looseness? Would'nt hurt to try to change it out to see if it may help. Looks like you covered everything else!
Yes, I like it. I use it in my 9mm & 40 Check their website for load data. The only advise I would give you is that if you load it light(slow) the powders dirty! If loaded hot, it burns clean. Go figure?