Bowling/lowering weight on next ball
Background--male 62yrs using Hammer Onyx Vibe 14lb ball 192avg normal target about 8bd @ the arrows mostly down & in shot with hook. Lane conditions--typical house pattern on synthetic lanes. Pretty accurate for bowling in one league friday night & sunday afternoon practice. btw I'm 6ft 225lbs. 30yr bowler, started with 16lb balls. 10yrs ago changed to 15lb balls; 3yrs ago switched to 14lb ball and moved avg upward from mid-170s to 190s.
Issue--considering moving inside next season btw 12bd-15bd at the arrows &use breakpoint about 7bd @ 45ft for better reaction using the lane conditions. I would like to buy the same ball but 13lbs.
Questions-- will i get more reaction by rolling lighter ball?  will I lose hitting power/get more deflections & less carry?  is there a tendency to overthrow a lighter ball when switching down in weight?
What do you think?
Thanks for your response!
-- will i get more reaction by rolling lighter ball? No, lighter balls has lesser weightblocks. Unless you have strong skills and know you can put enough hand in your shots to get the reaction you're looking for.
I suspect a fit issue. No reason a big guy like yourself should need a ball that light, unless you have some physical issues you haven't mentioned.
A ball should just hang in your hand, with little or no grip pressure needed to control it. When you move deeper, there is more oil in the middle of the lane. Dropping down in weight will have you probably throw harder, on more oil with a weaker (overall) ball reaction. Without a substantial change in your game to allow for the above, you'll encounter too much hook (depending too much on the dry outside boards for reaction) or too little hook (keeping the shot tighter and skidding too far down the lane with a difficult breakpoint to control).
 will I lose hitting power/get more deflections & less carry? Yes/Yes/Yes. Lesser core is less help downlane with ball reaction. Less weight is less dynamic effect from the momentum and energy imparted by the bowler. Carry is about angle of entry into the pocket. With your desire to try a bigger attack angle, you'll need better precision getting the ball to the right breakpoint, because your giving up what I mentioned above.
 is there a tendency to overthrow a lighter ball when switching down in weight? Yes. Footwork gets faster and you accelerate your swing to try to get your timing back.
Have you had your equipment refit when you changed the ball weights?
Thanks for the questions. Let me know what you do.