[Ersatzz]

I'm looking to get a set of bushings or bearings for my Retro Arms 8mm gearbox that I will be putting into an A&K SR25. From what I've read, bushings are much stronger than bearings, but perform a bit worse. I've seen people have problems with higher power springs crushing even ceramic bearings, so I'm wondering which I should get. Bearings or bushings, and of which brand.

I plan on using either a m140 or m150, shooting for about 500 FPS with an A&K SR25 (V2.5 gearbox).

 

[Zero Roaster]

Definitely bushings. You most likely won't be firing full auto anyways and rate of fire is a moot point on a DMR, but you'll need the strength of the bushing to handle those big springs.

 

[Airborne101]

Bearings are good if you are chasing efficiency, whether that's squeezing out every tenth of a RPS, or milking every possible shot out of your battery.

If you're not chasing either of those, then there really isn't a need to us bearings. And as said, bushings are more durable.

That being said, you can combine them. Lots of people run bearings on the bevel and step gear, while using bushings on the sector gear which is under the most load.