Currently there are a few things with aimed shots that seem a bit out of place (at least to me):
Chance to cripple It's kind of stupid to get your leg broken with a BB gun while wearing BA
So my suggestion is to make to chance cripple based on damage that was dealt. For example, you get hit in the leg for no damage - no chance to get crippled. If you take damage above some predefined value (for example 20 dmg) you roll normally. That value could be fixed or could be a percentage of your total HP.
Armor bypasses Lets compare MA and BA. The only differences that matter are: better defense against plasma and explode and slightly better defense against normal. For me there's no point in wearing BA when I can get almost the same for much cheaper price (that's my point of view, some people will always wear BA). I suggest the following - chance to get your armor bypassed should depend on the armor you are wearing . Here's a little example:
You are shooting at Bob's head. He is wearing MA. You hit him and it's a crit. You roll, the result is > 40 (add +20 if you have better crits) and Bob get's his armor bypassed. If Bob was wearing BA then you have to roll, let's say > 80 to get his armor ignored. This should be different for different body parts and different armors.I don't pretend to have much PVP experience (mostly trolling with a hunting rifle) so please critique