How to lower FPS on a G&G M4 RIS MAX?

[Neurotrauma]

I recently purchased a G&G m4 RIS MAX for use in outdoor field play, I have been reading up on a way to make it useable indoors as I would like to play in some of the local toronto fields, what can I do to lower the FPS on this gun so that I can play? I heard velocity reducers are not allowed in many fields?

[Steven]

You'll have to install a new spring. Velocity reducers are horribly inefficient, and are usually not allowed like you said.

[Neurotrauma]

what kind of spring should I be looking at? is this a simple process I'm new to airsoft never opened up one of them before?

[Slow]

M100 or m90 if you want to be really safe.

[Deadpool]

Then find a gun doc and have it changed professionally.

[Steven]

M90 or M100 should be under, or very close to 350 FPS. If you are uncomfortable opening your mechbox (www.mechbox.com ) give it to a Gundoc.

[Snowstorm45]

I don't think this needs a new thread, as it's pretty much the same question, but I have the M16A4 from the Max lineup (now a C7A2), and its specs on the site say its 480 (!) fps, which is way to high for, well, anything. An extra spring is included which I read is an M100. I'm not sure what "M" the stock spring is, but what fps should I expect when I put the M100 in, or would I need to know what the stock one is to know that?

[L473ncy]

It actually depends on brand. You're not going to get the same power from a SystemA M100 as you would from a Madbull M100 or a Deepfire M100, or a Prommy M100, or a Modify SP100. They're general guides only to be used to compare within the brand itself. That said an M90 should be good enough (and after breaking in the spring should be perfectly fine).

Generally though you can kind of guess what FPS range you'll be shooting at by installing X brand spring. For example with an M120 you'll usually get 380-410-ish FPS. M110 350-380-ish. etc.

Also airseal in the compression unit plays a part. If your piston leaks a lot of air then you're not going to get the full power from an M120 spring. If your compression is as perfect as it can be on the other hand you'll take advantage of all the power from the spring that possibly could be applied to the BB (accounting for inefficiencies and energy losses).

Note that ported cylinders also play a part in this. But that's a bit of a more advanced topic (truth be told I'm a bit lazy right now and don't want to type up a whole essay).

[B.O.P.E.]

the G&G web site has videos on how to dismantel mech box