CA M249 Upgrade Guide

[Bravo One-Six]

So.. I couldn't find one to help me through the process. Result is that I make my own. I should also note that I've gone through various websites and the upgrades/mods section here with no solid conclusive results.

The Situation:
Purchased a CA M249MkII about 4 months ago. Got it out to it's first event and was 'satisfied' with it's general performance. However, I feel a support weapon should be able to spit tons of fire down range and not just act like an average AEG. The goal here is to mainly increase RoF, and with a secondary objective of increasing FPS up to about 350-370 (enough to kick out .28's with enough juice to get them where they're going). Accuracy is no concern.

Current Setup:
Classic Army M249MkII
Stock Gears
Stock Spring
Stock Motor
Stock Piston
8.4 1700mah Battery

Proposed Solution:
I'm not an internals whizz. Never have been. But I know my way around a box enough to do what needs to be done.. I think.
Battery: 8.4 1700mah
Spring: Guarder SP110 (or equivalant)
Gears: Something more durable.. systema stuff?
Piston: Totally lost here.. something that will stand up to the wear.
Motor: I hear systema and guarder have highspeed/hightorque motors but not sure what I should be looking at.

Obviously I could up the voltage on my battery, but I imagine that would cause more wear than securing the internals first and improving the motor. Any suggestions would be more than helpful, and I'll be sure to update the first post with the info provided.

[Renegade)]

haha, i heard there was someone running around FR last weekend with an M249 lol, never would have thought it was you Sean:

To pump up your ROF comfortably and punch out more power, you might consider a 10.8V Very large battery, 4000mah+. Combine that with obvious upgraded bushings, torque up gears, MS110 spring would work fine, full upgrade reinforced cylinder/piston kit, and some other goodies Im sure some other people would sugest to you. I may not be 100% accurate on all that, but its fairly simple common stuff that would do what you wanna do.

[Spa]

I own a M249 and after actually working on it more then playing with it I learnt that when you do upgrade it make sure you have the right grease and lots of it. apperently with CAM249 theres alot of blowback in the cylinder with airloss and if you dont have the right seal it will cause fps loss.

A strong spring could also put to much pressure on the gearbox eventhough its reinforced. so using a modified boreup kit can help (using a caliper to shave the nozzle to the exact size of the M249 nozzle).

The M249 loves to eat through piston teeth and its normal so dont bother getting deep fire titanium pistons it will just mess up your gears.

If you do get a systema spring upgrade makesure to get a psring guide and a piston head with ballbearings espically if you are upping the rof.

I saw soemoen post about upgraded bushings...lol...no such thing for the M249 as they use 8mm flanged bearings (which are very very difficult to find, so dont break them).

Systema M110 with the spring guide, piston head, (boreupkit is optional), will put your fps up. You dont really need to spend 80-100 bucks on gears. just 20$ srping, 15$ guide and 20$ piston head are the recommended upgrades. and use proper grease, if theres not enough grease, the piston will have static friction which will make the piston harder to move in the cylinder which can cause the first tooth to be ripped off. grease gresae grease!!

good luck

[Zekk05]

CA stock gears are just fine, like Spa said. dont bother with new ones. But if youre putting a 10.4v battery in there... hellical gears may be required. Personally, i think you shouldnt be using more than an 8.4v battery, cuz anything more will cause some serious issues long term.

The 2 best things you can get are a SILENT piston head and an advanced trigger assembly. By far the two smartest upgrades Ive made, as they increase Durability, and in a 249 that should be your first concern.

In going with the durability theme... Id suggest a bore up kit over the spring. yah, 10$ vs 100$... but in the long run its MUCH healthier on your gun.

Remember, your gun will be putting more ammo through it in a month than most guns will see in a season, so your first priority for ugprades is what will be best for the guns health, rather than the cheap way out for performance.

I cant stress that point enough... otherwise youll find the gun spending more time on the work bench than out at the games.


IMO, you dont need an insane rate of fire. Real machine guns dont have a much higher ROF thanan assault rifle, its not their purpose. If you use it the way MGs are meant to be used, you dont need a high rate of fire. In fact, a higher ROF would be a handicap, as youll be running out of ammo a lot quicker with the same results as if you had a lowwer ROF.

[Gryphon]

Originally Posted by Bravo One-Six

I should also note that I've gone through various websites and the upgrades/mods section here with no solid conclusive results.

Dude. Seventy-seven pages worth of discussion on the CA M249.

http://www.arniesairsoft.co.uk/forum...howtopic=24379

[Bravo One-Six]

Ok. So I've been through 20 of the pages so far, starting from the last one and working my way towards the beginning. I've gleamed the following information:

1) If I'm upgrading the piston, I should use a TM stock one (because they get abused so completely anyways) or the Red polycarbonate one.
2) Apparently stock gears are acceptable for most of the stuff I want to do.
3) A lot of battery talk, but again, I'm hesitant to up the voltage unless it's necessary.

So far, it hasn't really answered too much regarding my RoF goal though. It seems to me most people thing the machine spits fire at a rapid pace, but maybe they're using high voltage batteries. Again, trying to find the right combo here for RoF and FPS... and something that won't self destruct. If I've missed something, let me know. I'll have to continue my slog through the rest of the 50 pages tomorrow.

In addition, I appreciate the input regarding durability/reliability in this thread. It's definitely a major concern and will be the first thing I address before I add any other internal upgrades.

[Spa]

are the onyl epople who know thier M249's from winnipeg? lol

[Zekk05]

Gauging by this guys "suggestion":
'10.8V Very large battery, 4000mah+. Combine that with obvious upgraded bushings, torque up gears'
I would have to agree with you on that Spa.

In my time here, Ive gathered that Manitoba / Winnipeg has the highest number of full out LMGs. Its in lieu with our hardcore mil-sim community.

[Gryphon]

Yep. At least 11 or 12 that can be identified right off the top of my head, although another source puts the number at double or even triple that.

And who was the first in the province with a CA M249?

Oh yeah, that's right baby. Trendsetter.

[Spa]

oh gryphon! always on top of things

[Fox Hound]

any news on this bravo six? i just purchased a CA m249 MK II and i want mine to go like this zzzzzzzzzzzzzzzzzzz.... something like a chain saw

[ThunderCactus]

Originally Posted by Bravo One-Six

1) If I'm upgrading the piston, I should use a TM stock one (because they get abused so completely anyways) or the Red polycarbonate one.
2) Apparently stock gears are acceptable for most of the stuff I want to do.
3) A lot of battery talk, but again, I'm hesitant to up the voltage unless it's necessary.

Well I'm using a G&P 249, internals parts are all the same it's just in a standard V2 shell instead of the brick CA uses.
I suggest either the systema polycarb piston, or if you want to spend a bit of extra money, the prometheus piston (things still scares me).
CA gears are good, they'll last no problem.
I use a 7.2v 4200 mah battery in my 249 and that gets me to about 840rpm, the 8.4v 4200mah (as it comes normally) gets me to 1020rpm which is a real good ROF. Now we're not using the same motor, and you want a bit higher FPS than I do, but the wiring in the CA249 is fairly fat so you should get similar results.

[Fox Hound]

would anyone recommend the promethius up gear sets? i want to know if this is reliable stuff to pump over 50K rounds.

what makes the CA m249(stock) faster than most stock aeg's? could it be the placement of the gears?

[ThunderCactus]

You can run 400fps on standard gears if your using a large battery. If you want your gears to last and don't mind losing just a little ROF, get helical torque up gears (not super, just regular torque up). This will be easier on your motor as well. If you never want your gears to ever break, get prometheus helical torque ups. It's as if they used actual STEEL in their construction or something lol

[Fox Hound]

i dont understand why spa recommends the Bore up kit, wouldn't that reduce my FPS being that my spring is probably going to be too weak to begin with?

and what about the box mag? using a larger battery would the box mag lag behind since the gun is firing so quickly?