Hello, this is my first post. I have found many answers in these forums especially for teching my JG AUG but i cannot find a similar thread to this. I recently ordered a new ML bucking with its own ML nub and a 420fps spring. So I thought since the spring is around 420fps that i should get the 70 degrees hardness bucking because it is the recommended for those FPS (360 to 460). But then I remembered that all fps are measured with .20g BBs and since i use .25g BBs that means that my gun will shoot probably less than 420fps, around 370 i guess. So my question is: Is the bucking hardness fps recommendation for .20g BBs? So If i use heavier BBs with my AEG then should I get a softer bucking like 60 degrees (300 to 400 fps). I know that it also has to do with climate, it is hot where I live. Can someone experienced guide me through this process? Or i guess I can buy both 60d and 70d and test which one is better?