M24 upgrade path
 

Greetings,

Just read through a lot of material, still trying to figure it out...

1. APS2 upgrades are pretty much what I have to use, right?
2. A zero trigger assembly will help with an upgraded spring, since the stock trigger will be much harder to pull, right?
3. A 170% PDI spring should yield about 450 fps, right?

Anyone have suggested reading material for this project?

Thanks!