I'm new to the Glock world and have a few questions. First, How much does a reduced power recoil spring help with recoil? Secound, I'm not reloading yet for 9mm (just need to bye the dyes) so I will be shooting factory ammo so what # spring will I need to work properly? Last, do I just need the spring or do I need to buy the rod too? I will be shooting this in IDPA so I want to keep my G17 in the SSP division. Any advice on what would work and where to buy it would be greatly apprecated.