Upgrades for Classic army m249 SAW
 

I have a classic army m249 saw mk2, i used it for the first time yesterday and i was very happy with the performance. It was around 390-395 FPS and ROF was around 20 RPS.I am using a 4000 MaH 9.6v battery with a 40amp discharge rate. I want to put some upgrades on the gun. I don't need more fps or higher rof. The reason i would put in upgrades is to make to gun last longer and be more durable. So what upgrades would increase the health of the gun and make it last longer?

Honestly, if you're happy with the performance as it is, run it till it dies.
Just bust the box right out. You *can* gut and replace everything in there, but there's really no sense doing it if you're happy with it as is.

You should probably modify or replace that hopup unit though.

Edit:
Here's why;
Nearly any upgrade part will be better than stock, but aftermarket parts don't make a good gun. Aftermarket parts where conscientiously and correctly applied make a good gun. A lot of upgrades (especially it seems within LMGs) are chasing dragons. Tilting at windmills even.
If your gun runs well enough out of the box, and/ or you adpt your play style to what it can accomplish, your gun is already a good gun.
Your stock parts may fail sooner than fancy ones, but if they haven't failed yet, they go into the tickle trunk and are never used again. That's a net waste of your money and materials.

You can benefit from taking your existing parts and correctly applying them. Gut the gearbox back to the outer walls. Get everything clean to an eye-rollingly anal standard. Re-shim and re-lube everything with fancypants lubricant (not too much!). Correct for angle of engagement. Reassemble everything and lubricate the charging handle, spring, and guide rod for it if you want to feel through.

With this done, the stock gun you're already happy with could last years and years without a failure.
Start a swear jar for the day it goes "GRRRRNK", and replace the innards top to bottom with the finest snake oil, happy in the knowledge that you earned it.

Thank you so much, that really helped!!

You should make it a kill jar. A quarter for every kill the gun gets at a game. If by the time it breaks you don't have enough money to fix/upgrade it, she stays dead.

Have it earn it's keep.

Daytona Kit.

/Thread

Lol +1 to what EOD Steve & Cliffradical said. Check out my build threads for my CA MK46 (M249 SOPMOD) and A&K MK 43 Mod 0 (Modern M60). Both gearboxes are nearly identical, honestly just read it, there is a load of info I won't even get into in this post.

Threads:
http://www.airsoftcanada.com/showthread.php?t=175310
http://www.airsoftcanada.com/showthread.php?t=168879

As for a general overview...

First and foremost upgrades should be selected for their reliability. Above ALL else. Period. End of story. Why...? Well you're shooting WAY more than other guns. At 20 RPS, that's 1 midcap every 5-6 seconds of continual fire. Realistically, in heavy engagements, you could go through 50,000 bbs in a game, vs 50,000-100,000 in a season with a rifle or SMG.

So with that said, if you're opening the gearbox:
1. Clean the gearbox of that 'gunk' that's supposed to lube the gears efficiently. Remove and clean all parts.
2. Shim the gears and dial in the motor height.
3. Lube the gears adequately and cycle them by hand without the motor to spread the lube out through the teeth without it flying off under power.
4. Lube all moving parts (non compression parts) like the tappet plate, and piston rails with the same, or similar, grease as the gears.
5. Lube all compression parts with silicone oil. (piston head, nozzle) This is what I use, seems to work very well. Not saying "buy this!", but something like it will be adequate --> http://www.evike.com/products/44392/
6. Replace the bearings on your gears for bushings. This will mean a mandatory re shim, but it will increase the life of your gearbox immensely. See this post: http://www.airsoftcanada.com/showpos...11&postcount=6


Do the above if you plan on running the stock gearbox until it dies. If you don't know how to shim, Youtube is your friend as is your local, or not so local online, airsoft retailer to purchase shims.

Either modify or just replace the hop up all together. The factory M249 and M60 design is super strange. If retaining, at least remove the nub and replace it with a piece of pen tube sized to the same length. Consider doing either the Teflon Tape or Dental Floss mods to the end of the barrel to increase consistency and reduce air loss/bump FPS. This is more of a consistency/range/accuracy mod though unless you have a major air leak which I doubt.

Consider disassembling the box mag and lubing it as they have little to no lube from the factory. Plastic on plastic + high useage probably won't fair super well long term without it.

Finally, be prepared for things to break. Expect it even... (For example I carry spare gearbox parts to games in the event something fails). Start a log for your gun which contains the date, weather conditions (ie dry/dusty, wet, drizzle, cold, etc), and rounds fired. Eventually you'll see a pattern if the same parts keep failing, and be able to predict a failure and change said part out before a failure occurs. Since LMG's when used a lot will burn so many more rounds, wear is accelerated greatly and parts will fail much sooner than they would on a rifle or SMG. The best mod you can do is learn your gun, your gearbox, and how to properly tech it when it fails. Clean and re lube it regularily and it will last much longer.

Thanks Magwell!! I will definitely do that.

Ran mine at 25rps for a long damn time. There's a lot of bush tonpunch through in manitoba. The volume of fire also increases its ability to suppress people, even if you're only firing 5-10 round bursts.

Also, step 1 to making a ca249 more reliable: buy a g&p249 lol