Classic Army M249 parts questions.

[SharmanAJUSMC]

I am getting a CA M249 mkII here pretty soon, i have read online that one of the problems people seem to have is the piston stripping, and the piston head breaking. i am going to replace these parts first thing wheni get it. however i am not sure what kind of piston/head i should get. can anyone give me some ideas on the best (and not horribly expensive) way to upgrade this weapon.

also did i miss any major problems, is there anything else i should change out ??

[Ganef]

The one I rock has been going strong for many games with no problems. The only issues that I have had with it is battery and mag feeding problems.

[SharmanAJUSMC]

what where the problems with feeding and your battery?? are they serious problems?

[Ganef]

I have used 2 different box mags the first, a classic army one never missed a beat untill the whole thing self destructed during LCV. Because it is so large you tend to rest the gun on the box mag and that cracks up all the internals so when you take it apart to clear a jam the winder crumbles away. I have been currently using a mag mag and it works great though the loading port needed a bit of widening and the bb tube inside the mag needed to be shortened a few rings to make a smoother transition upward to the gun. It also has a port where the winders battery allows bbs that inadertinly find their way down under the battery and into the internals of the mag jamming it. I repaired most of the problems today and took out the staple that was jamming the mag and now it runs flawlessly. make sure you keep your bbs clean and free of debris so that stuff dosent get into the box mag and jamm it. I had a tiny leaf jamming my bbs at LCV.
As for battery problems, I run 9.6V 2500mah batts and I have gone through as many as 3 batteries in the course of a days fighting, I have a peq box mounted to the side for quick access and changing of the batts and cary upwards of 4 with me at all times. So you need a lot of good batteries to keep a saw running. All in all you realy have to be a keen airsoft armorer to keep the saw in top condition at all times.

[SharmanAJUSMC]

hmm, ok so, 1 i shouldnt rest the weapon on the box mag, is there anythingi can do to reinforce it so that it will not  do the same thing yours did?

have you replaced any of the internals?


I'm not the greatest airsoft armorer, if it was the real saw i could fix anything that happens to be wrong with it. so i guess ill have to just do the ol' trial and error thing i guess, can you give me any pointers on taking apart the gearbox?

[Ganef]

I wouldnt even touch the gearbox. It is rock solid and dosent need tinkering like other airsoft guns. The armoring I was referring to was mostly concerning fixing mag, battery, hopup and jamming issues in the field. I also carry 4 M4 standard mags with me in case of box mag failure. As for the box mag problem, there realy isnt anything that you can do except treat it nice and dont bang it around like I did. I originally didnt like the mag mag but it is small and with modification is just as fast at loading as the CA box mag was.
It wasnt in my posession when the upgrades were done but as far as I know nothing was done except a different spring and a tight bore TN barrel that I just put in.

[SharmanAJUSMC]

hey thanks for the great info man, i appreciate it.  

what kind of spring do you use? what does it chrono?

i have read many times on the internet that the stock piston and piston head arent that great, and they recommend puting in a better piston at least, are you sure that someone didnt already do that when you got yours? did you get it new?

sorry for all the questions but i like to be well informed if im bothering you just let me know

[Panzer]

When CA first shipped the M249 almost all of the Pistons broke due to an issue with the way the hop was set. if you do replace the Piston & head i'd recommend the Deepfire I have tried a couple in mine and it seems to work the best. One thing I would recommend is do not operate the CA 249 at over 8.4Volts. Ca does not recommend it and I had misc problems with mine when i used both a 10.8 & a 9.6 batt.

The seals in the CA 249 are really good. I actually am using a stock spring and it shoots around 320-340 depending on the chrono. With a 120 it was over 420fps go figure. You can change out the spring in under 3 minutes so it is not hard to try a few out on a chrono before deciding which to go with.

[taz]

I haven't had any problems with my CA249. I installed a systema m120 spring and chronoed at 380 fps with .20's

[Ganef]

Just did an overhaul on the bone saw too see how the inerts are and it seems as though the first set of upgrades were just a new piston. All of the rest is stock including the spring. The gearbox is so easy to work on and comes out so fast. The cool part about working on it versus a version 2 gearbox is that the main spring is already out of it so you realy dont have to worry about breaking anything when you take it apart.

[Ganef]

Here are some pics for reference:

The bone saw as it stands now, almost a Mk48 mod 0.


The inerts:

[SharmanAJUSMC]

alright, so i should replace my piston, i was thinking deepfire or a prometheus hard piston.  im kinda bummed that a 9.6 battery isnt recommended since the 249 i am getting comes with a 9.6v 3300 mah nimh battery. so which kind of battery should i use then?

[Ganef]

I was informed last night that this saw has a hurricane full tune up kit, so I guess that you would need to replace the piston. Either of those should be fine, and as for batteries I run all 9.6V in this saw and havent had a problem, though I do trust panzer's opinion.

[SharmanAJUSMC]

ok, so basically, if i replace my piston i can use the 9.6? im not sure exactly what a hurricane full tune up kit has in it, anything other than a new piston that i should concider gettting in order to fun the 9.6v batt? i really want to have a killer rof with an an m120 my target fps is just slightly above or below 400fps. do you think its possible to reliably obtain this, anyone have any suggestions?

also do you think its possible to replace the ca box mag outter case with the outter case from real saw boxes?

[Ganef]

I would worry more about reliability than rate of fire. Panzer has high speed gears in his and it humms like a powerline but I have never felt underwhelmed by the output of the bone saw. Get a new piston, get an m120 to try out and a 9.6Vbatt and you should be gtg. It is not realy worth your while to fit a real box mag on the CA one, too much hassle for not being that much better. Mag mags are great but need a bit of modification and TLC to keep them in peak form, i can help you out if you get one. Just get it and bring it by and I can give you a good overview of how it all works.