A&K M249 hopup repair / replacement

[Crunchmeister]

It seems that everyone agrees on 2 things about this gun - it's a pretty badass piece of kit for the price, and has a shit hopup. I only briefly had a chance to shoot it at a longer range this past weekend, and beyond 75 feet, the BBs just drop to the ground. Anyone who knows this gun will agree that out of the box, the hopup is shit and basically has no effect on the BB trajectory, regardless how much it's adjusted.

So that being said, what is the best suitable replacement hopup for this gun? Does it involve just replacing the rubber and bucking, or the entire hopup unit itself? I've heard that installing the bucking sideways is a quick fix that yeilds alright results, but I'd rather either do a proper mod to the existing hopup, or just replace it altogether with a good working unit.

[DENZILDON]

What's up crunchy?!

What I did was I changed the hop-up rubber and I used a piece of 16 gauge wire strip (no wires inside) as a bucking. (very responsive). Trial and error on how long you need to cut the strip.

You can also place a material in between the original bucking and the cap to close the gap and get the bucking to push further. In Arnie's review he used a piece of plastic packaging.

I also did the glass sealant airtight mod. Currently mine is shooting an average of 390 to 400fps with an m120 spring. No other upgrades and stock batt.

[jtf2-phalanx]

Originally Posted by DENZILDON

What's up crunchy?!

What I did was I changed the hop-up rubber and I used a piece of 16 gauge wire strip (no wires inside) as a bucking. (very responsive). Trial and error on how long you need to cut the strip.

You can also place a material in between the original bucking and the cap to close the gap and get the bucking to push further. In Arnie's review he used a piece of plastic packaging.

I also did the glass sealant airtight mod. Currently mine is shooting an average of 390 to 400fps with an m120 spring. No other upgrades and stock batt.

+1, I did the same thing and it works like a charm. Using the wire makes for a stiffer bucking so I'm sure it will last longer and generally be more responsive as Denzildon mentioned.

Also, you might want to replace the switch too as mentioned before in a lot of the reviews. It makes the gun shoot when you want it to rather than whenever it wants to.

[Crunchmeister]

Thanks for the info guys. I'll give that a try and see how it works out. As for a tighter air seal, mine is shooting pretty consistently at 395-400 fps as it stands, so I don't think that will be required.

The only other mod I'd like to do is to bring up it's rate of fire. It just doesn't feel tight to have a support weapon that shoots 13 bb/s when my 2 main rifles (CA M15 and JG416) shoot about 22 bb/s.... The battery I got with my (used) M249 is a 9.6V 1500 mAh and it doesn't quite seem to push it even to the rof I've seen people in Youtube videos getting with a stock 8.4V. I'd like to get it up to about 20-ish and make it as intimidating as it looks...

[ex]

Another option for a stiffer bucking is to just put a wood (round) toothpick into a standard bucking and nip off the ends. This works great for a very responsive bucking.

[Crunchmeister]

Hey, that doesn't sound like a bad idea either. I love hearing the creative things people come up with.

Just a question on the gears here. Does this gearbox take the standard V2 / V3 gear set, or are different gears required? I'm considering installing a high speed gear set at some point.

[ex]

I should also have added to use a "Bamboo wood" toothpick so it doesnt swell when it's damp or humid out.

[DENZILDON]

Version 2 gears would work but for the most part a lot of A&k m249 users don't bother to upgrade since the stock gears are able to take an m130 spring with no problems. I say keep it stock until it breaks on you.

As for rate of fire, mg's are normally a slow firing gun. I personally don't want to increase my rate of fire even with an upgraded spring since it's already a bb eating monster when you are the fire support role for your team. But if bb's are not a problem I would suggest to start an upgrade with a 10.8 batt then a better motor if you want more action. Here is the other thread that we discussed about upgrades for this gun.

http://www.airsoftcanada.com/showthread.php?t=54355

Regarding the bamboo bucking, I you want to go this route, try to get a hard hop-up rubber. I softer ones might get damaged faster since the rubber will be pushing in to a much more solid object. That's the reason why buckings are made out of rubber, elasticity to avoid tearing of the hop up rubber.

[medhatboy]

anyone know a good place to get a re-placement o-ring that keeps the hop up dial in place, mine snapped, and this little town I live in has very limited resources for stuff like that.

[m102404]

Crunch,

I'm sure you might have come across this one already, but here's a great write-up (hopup part is way down in the review) in case you haven't.

http://www.arniesairsoft.co.uk/revie.../cat/16/page/1

In case the link doesn't work, it's in the review database of www.Arniesairsoft.co.uk

Best of luck!

[Crunchmeister]

Yeah, I read that review even before I received my SAW. That's how I knew right away what the issue was.

What I ended up doing was using the insulation from some 16 gauge wire and made a new hopup bucking out of it, and it now works great.

Thanks for the info anyway though. You're always so helpful when I have a question about something.

[m102404]

I was 99.999999% sure you had already read it....but I haven't seen the link posted here on ASC and thought it might be a good easy resource for the next guy.

For the nub you made...was it the same size as a regular hopup nub? Little longer/shorter?

Anyone want to sell me an A&K M249 Para...I'm freaking dying for one! :banghead:

[Crunchmeister]

I posted the info in my review thread. The original nub was so small that it didn't press down on the sleeve at all, even at the maximum setting. The wire insulation I used was significantly thicker than the original nub (and 16 gauge wire isn't that big, but it was bigger than the original nub. And it seemed to work fine. I laid it sideways like the original (vs the 'fix' of standing the original on end like that review states). I reassembled the barrel / hopup assembly, tightened the hopup, and I could easily see its effect on the sleeve. I tried it out, and it worked fine.

[six4]

Originally Posted by Swatt Five-Six

anyone know a good place to get a re-placement o-ring that keeps the hop up dial in place, mine snapped, and this little town I live in has very limited resources for stuff like that.

you should be able to find a suitable replacement from any auto parts store or rona. take your broken one with you and match up to a new one as best you can.


cant wait to get mine back from my gun doc. not one box mag of ammo through it and she broke down,,,frozen mechbox. been repaired with new shims,proper cylinder and better motor as mine was seized. saturday morning cant get here fast enough.

[killadude]

Originally Posted by Crunchmeister

Yeah, I read that review even before I received my SAW. That's how I knew right away what the issue was.

What I ended up doing was using the insulation from some 16 gauge wire and made a new hopup bucking out of it, and it now works great.

Thanks for the info anyway though. You're always so helpful when I have a question about something.

could you make a review, possibly with pics on how to do that? because i am probably going to get this for my soon coming b-day as a first airsoft gun, and i want it to last as long as possible, because noones gonna buy me another one for awhile. and also does that mod improve accuracy, and does it screw anything up? please respond!opcorn: