''swiss cheezing'' a piston, good or bad idea?

[yan101]

I've seen a couple of youtube video about it,
is it something worth doing?
if yes, what to expect +10fps?

is it gone reduce the ''life expectancy'' of the internal?

[MaciekA]

I'm guessing you watched ASTKilo23's video, or someone who was inspired by him. If so, you should go to YouTube right now and click unsubscribe. That guy has some bizarre ideas about gearboxes and such.

Just to get this out of the way: Swiss cheesing a piston in no way, shape or form can increase your gun's velocity. If anything, you may lose some velocity if you manage to reduce the momentum of the piston due to weight loss.

Swiss cheesing is useful in AEGs where the piston return time is not fast enough to get home before the sector gear has completed a rotation. If the sector gear can rotate faster than your piston's return time, you get something called pre-engagement. This is where the sector gear interrupts the piston on its way back to the front of the cylinder and shreds through the teeth on the piston's rack.

Pre-engagement generally only happens if the piston is somehow artificially slowed down (because of binding, i.e. the piston is having trouble moving through its range of motion due to friction) or if the rate of fire of your AEG is extraordinarily high, or if the spring isn't strong enough to move the piston very fast, etc. You get the idea.

Unless you are building a very high speed build with a relatively low velocity (fps), I don't swiss cheesing your piston will not bring any benefits. It is merely a fix for pre-engagement, and if you are using a strong spring you can usually avoid pre-engagement anyway.

edit: Also note that pre-engagement generally only reduces the weight of pistons by mere grams. Most people who are cheesing their pistons are trying to fix improper feeding at rates of fire north of 35rps. Unless you are building CQB guns that are in this range of RoF or higher, you can safely avoid drilling holes in your pistons. They'll last longer.

[Schoolboy]

Works for me man, Heck you can even buy pistons with air-ports already pre made.

[Styrak]

It will have no effect on your FPS.

[ThunderCactus]

eh, unnecessary really