As mentioned before, the screws don't actually need to be that long, it's only so you can start them against the springs/outer ring plate. This is not normally too difficult to do even when the screws are cut a bit shorter. Once you start to reassemble the outer parts you will wish the screws were only about 3 threads long, as the procedure for setting up the outer plate so it runs with minimal wobble can be somewhat "time consuming". I gave up swapping springs around in favor of placing shim washers in the right spot to minimize this problem. But there are actually many hidden things that can cause this, and some of them are not that obvious.