Questions...
 

Ok... I have a G36C and I got some questions about it.

1. What will having a gear box to use 7mm or 8mm ball bearing bushing do for the gun?

2. What will a new gearbox do for the gun, and how will it affect it?

1. Ball bearing bushings allow you to increase rate of fire, reduce battery consumption and reduce gearbox whine. However, due to all the small moving parts, they have a much lower load limit than sintered or CNC bushings. As a result, you need to get the proper sized bearings for your spring weight. 6mm bearings are good to PDI 120% / Systema M100 / Prometheus MS100SP / Guarder SP90 levels.

7mm bearings are good up to around PDI 190% / Systema M130 / Prometheus MS120SP / Guarder SP120.

No idea about 8mm, as nobody in Canada has a need to push their gun to shoot so high. But if you want better reliability for lower rated springs, there's nothing wrong with using 8mm bearings.

2. That depends on what the gearbox advertises... if it's called a "reinforced gearbox"... then it's reinforced. Surprise! If you had a link to what you're referring to, that could be answered easier.

what about guns that come stock with 7mm bearings

Guns that come with stock 7mm gears would be the same as listed. Systema M130 and equiv. will enjoy 7mm ball bearing gears for many moons.

What about? If it comes with it, then it's been tested to handle okay.