Springs! - M100 M110 M120 etc etc

[Furbloke]

Hello. I've got a question regarding springs.

My CM16 is only shooting 280 FPS as we speak. I would like to get it up to 340 FPS

Currently it has its stock 233mm inner barrel on it. I'm looking at getting a 505mm inner barrel (As well as a barrel extension and a heffer of a supressor)
Nothing within the gearbox is stock, its all aftermarket, besides the spring.
The Hop unit is after market too, and I'm using a prommy bucking.

What I've been told is that I need to upgrade my spring, but I'm confused as to what the M100, M110, M120 etc means


Can anyone explain it so I can know what to go for to achieve 340? And if you can, explain it like you were talking to a toddler who was semi literate and incredibly thick?

[Sitting Duck]

Re: Springs! - M100 M110 M120 etc etc

forget barrel - 510mm is probably pushing it and you would need full cylinder no ports
but still 510mm long would be at the absolute max
what was it shooting before and how old is it - presume 280fps is on .20's

try to establish if you got a crap air seal somewhere first but anyway....

M100 = 328fps as a ball park figure - with no air loss you might be a bit above that
M105 by Element will place you bang on 350fps - well 344.4 if you like

if you are much below that then you have an air leak/bad seal somewhere

M100 = 100 meters per sec or 328ft per sec

M105 = 328fps x 1.05 = 344.4fps

tbh I'd change spring, if possible have a bearing spring guide in there if still using stock spring guide
check for compression, don't settle for good - aim for GREAT compression on piston head o-ring & ptfe the cylinder head
chrono and go from there....
get box 100% sealing and if still down on fps then the leak is at hop unit/bucking/nozzle

expected fps values will vary for each build and usually you can expect a little more fps on longer tbb
than shorter wider/stock barrels - you should be close to those figures even on a short Raider or hitting those figures no problem on long raider
hope some of this helps

Do not use a much higher spring than required to compensate for a bad seal
using say a m120 to achieve 350fps is not wise placing more stress and slower rof/response than is needed
if you are losing fps - fix the leak not dodge the problem with higher springs

[Furbloke]

Re: Springs! - M100 M110 M120 etc etc

My cylinder isn't ported as is. I'm using ASG: piston head, piston and air nozzle. I'm quite confident in the air seal

I already have fine gauge PTFE tape wrapped around the cylinder head (perks of being a plumber, makes it easy to find). I have an SHS bearing spring guide too already.

The air seal is really quite nice actually. Theres little next to no, air loss whatsoever.

I digress


What I can gather from what you said is the "M" represents Meters and the number represents the M/s? Hmm.. Okay. Right. I'll look at an M105 spring then. I mean, I've spent over £200 in upgrades. I want a GREAT gun, not a GOOD gun.

Thanks for the help

[sj_asc]

Re: Springs! - M100 M110 M120 etc etc

The ratings of the springs are as Sitting Duck says, this is a ballpark figure though as it does depend greatly on the gun. If you have a better seal and or longer and or tighter inner barrel you will likely end up with more than the rating. If you opt for something lower end (SHS, ZCI etc) you are also more likely to end up with a mis labeled spring.

Remember when checking the compression assembly and nozzle that you are sealing the nozzle when its in its furthest forwards position as that's where it will be when making seal with the bucking lip. The biggest air leak will always be between the air nozzle and hop bucking - the chamber's position has a lot to do with this.

ASG gearbox parts are actually just a re-brand of Lonex, and for the most part their parts are mid to high end, depending what you are buying. In short, some of their parts are really decent and others there are better alternatives.

It also isn't simply a case of buying a bunch of half expensive parts and throwing them together and believing that they are doing their job, the art of airsoft teching is actually being able to identify and understand the parts that you are buying and being able to make them work correctly together which often involves careful modification.

Also it's worth nothing that if you are running a shorter barreled gun that you can actually gain FPS with common weights (.2 and .25g) if you switch from a non ported cylinder to a ported one as this allows the piston time to accelerate before hitting compression creating a higher pressure spike.

[Andy Mc]

Re: Springs! - M100 M110 M120 etc etc

Hi guys

Great thread, I've certainly learnt a lot myself just reading through this, I have a few questions myself if you don't mind me jumping in on this op
I have recently and still am turning an ARES G36 into a DMR setup, all parts bought from zeroin
I received my parts upgrades today, MERF mosfet v3, Guarder cylinder upgrade set, ICS hop to name but a few, and it also has a Prowin CNC hop unit already installed, and the stock 490mm inner barrel.
Now previously I acquired the gun as a non firing one, I stripped the GB and did all the lubrication etc..
1. I put PTFE paste underneath the o-ring of the piston head.
2. used silicon grease on the nozzle and inside the cylinder etc.. and since..
I am getting between 415-425 fps on my chrono, say 4 shots are at 422, then one shot at 415, then 1 at 425, then back to a few at 422 etc..
Now is that in anyway over working the internals? as they are all stock parts atm.

Questions I suppose I really need to know:
1. is putting ptfe grease underneath the o-ring of the piston head a bad thing?
2. When you guys have mentioned sealing the nozzle in the most forward position, what does that mean, is that just a case of ensuring there is silicon grease in that area of the nozzle?
3. I am looking at a 120 or 130 spring, can you advise which make would be the best option to get around 400fps (to make it legal for my site) I see the 120 should be around 394, but as mentioned in the thread with a longer barrel fps might go up slightly?
4. the Guarder upgrade set has a ported cylinder, do I need a non ported one with the barrel length of 490 and to achieve the 400fps?

Thanks
Andy

[colinjallen]

Re: Springs! - M100 M110 M120 etc etc

Andy Mc,

Regarding your first point, I cannot see why that would be a problem; however, I am slow not sure what good it would do.

Regarding your second point, it means that you should check the air nozzle/hop rubber seal when the nozzle is in its most forward position. Never ever get grease near the inside of the hop rubber.

Regarding your third point, trial and error; it all depends on your particular gun.

Regarding your fourth point, you probably do but, again, trial and error.