REDUCING FPS with a ported cylinder?

[Jimski]

Hello,
I have an AEG that's a bit too powerful ( ~415 fps ) and I want to field it next sunday.

I don't have a spare spring, however I do have a ported cylinder somewhere close at hand.

my question is: if I mount it, is it gonna reduce the FPS enough to make it OK with the field rules ( 400 fps ) ?

thanks!

[Dawnbringer]

It would reduce yes, most likely below the 400, how far depends on where the porting is, different cylinders are ported at different spots depending of the inner barrel length they are meant for. It may reduce it too much though. I know if I flip the cylinder around in my 36c the bbs barely make it across the room, I would suggest putting it in and trying it out, assuming you've dealt with the inner workings of a mech box before.

[Whozat]

Trim your spring.

[Jimski]

It'll be a mp5k cylinder, so I guess the hole is big enough
it's just a temporary solution before I get the exact spring I want.

anyway thanks !

edit: trimming the spring, yeah I thought about it. but what length shoud I cut?
I'm basically hesitating between both, though I must admit I'd rather mount another cylinder than wreck a good spring...I dunno...

[ILLusion]

An MP5k cylinder will probably get you to about 320fps. If you fire in full auto, you'll probably get 290fps for successive shots.

[Jimski]

ah crapz that suckz !! it's way too low.
I need a spring

thankz !

[ILLusion]

Really? Because I have springs for sale...

In any case, put in that cylinder first and see what velocity you get - just chrony it. It doesn't hurt to try. You may be surprised us and get as high as 340fps in semi-auto. But it will almost be guaranteed that successive follow-up shots in full auto will suffer due to suckback. The MP5K's port allows less than half the volume of air that an unported cylinder provides.

What are you basing your velocities on? Do you have a chronograph?

[CDN_Stalker]

You can reduce your fps by reversing your cylinder so the port is closer to the front.

Am not kidding (ok, I'm kidding about you doing it only), as it'll drop your fps by quite a bit.

[Jimski]

at the moment it's got an unported cylinder, but I think I won't put a ported one anyway...
i'll changhe the spring instead, it's cleaner

[Spa]

put in a .25 BB when they chrono it and say you are using .20's so it will drop it below 400 fps:P i heard ppl do it before games just incase they are 10-30 fps over.

[Jimski]

Originally Posted by Spa

put in a .25 BB when they chrono it and say you are using .20's so it will drop it below 400 fps:P i heard ppl do it before games just incase they are 10-30 fps over.

that is not considered a solution in the present thread, sorry.

[testtube]

Originally Posted by Spa

put in a .25 BB when they chrono it and say you are using .20's so it will drop it below 400 fps:P i heard ppl do it before games just incase they are 10-30 fps over.

Hmm and where do you play.

[Nova316]

Always can borrow a TM velocity reducer?

[ILLusion]

Originally Posted by Spa

put in a .25 BB when they chrono it and say you are using .20's so it will drop it below 400 fps:P i heard ppl do it before games just incase they are 10-30 fps over.

That's a great way to cheat and break the trust that this game is based on.

Smart game hosts will force a test BB on you.

Also note, that if you're hitting 415fps with your hop up completely off, your velocity should drop to around 400-405fps once you adjust your hop up to the proper level.

[CDN_Stalker]

Originally Posted by ILLusion

That's a great way to cheat and break the trust that this game is based on.

Smart game hosts will force a test BB on you.

Also note, that if you're hitting 415fps with your hop up completely off, your velocity should drop to around 400-405fps once you adjust your hop up to the proper level.

Yes, and very few places I've played at force player to go full hop up off, it's time consuing to get it back to where it was after you wasted many rounds and time setting it properly (easy with an AEG, damn hard with a bolt action). Besides, we tend not to play with hop up full off anyways, and there are cases (such as both my MP5s) where the hop up rubber has swollen from a lot of use and oil maintainance that the hop up is set full off yet still rests at the prime amount of hop up. Both mine easily get past 200ft with 0.25g and 0.28g BBs, hop up lever bottomed out completely.

What AEG is it exactly you have upgraded here? We know you put an MP5K cylinder into it, but what gun? And what chrony was used and what type of ammo? There are times cheap 0.20g (because few smart players use it outdoors, so if it's only for chronying, hosts can afford to go cheap........... saw it recently where the chrony ammo was just that, and because they were cheap BBs a lot of AEGs that had tightbores plugged up repeatedly) can cause bad readings in gun because of lousy tolerances and such. Smaller sized BBs will read lower, better quality ones can read higher since less air passes the BB as it goes down the barrel.