FPS Problems

Hey guys I just had a quick question. I have a Mad Bull M140 in my gun but it is only shooting 415 FPS. Could it be a compression problem? I will list all the other internal parts so you might be able to see the problem. (Please note that everything was professionally installed.)
Mad Bull Ver. 2 Tight Bore
Steel Bushings
Systema Torque Up Gears
Aluminum Piston Head W/Bearings
G&P White Polycarb Piston
Metal Ver. 2 Spring Guide W/Bearings
9.6V 4400mah NiMH
Mad Bull M140 Spring
Systema Hop Up Bucking

Thanks for your help.

i dont know too much especially compared to seabass....but have you gone to a longer barrel? if so, you may need a bore up kit to prevent suction of the BB as it is in the longer portion of the barrel, which in turn would slow your fps down a lot....but that said, it would need to be a decent amount longer i would think to make much difference.

Also, if the air nozzle isnt fully sealing or something....that could be it....just trying to help

l8r

I had a similar problem with my Echo 1 M14... had an M140 in it for a while and didnt notice much of an FPS gain, then I put in an M150 and it still didnt shoot much over 400 fps. My guess is that you have either a damaged air nozzle or it is possible that the spring sat compressed for a while and made it slightly weaker than it should be. There are other possibilities, but those are pretty regular problems people experience.

Thanks for the help guys. I know it isn't barrel length so I will try a new air nozzle.

If that doesnt work... maybe try a new o - ring around your piston and re-lube the cylinder itself to make sure you are getting full compression from your piston.

Hey I just tried shooting a Coke can and(poor mans chrono here: http: https://airsoftforum.darkbb.com/general-airsoft-discussion-f3/poor-man-s-chrono-t38.htm ) it penetrated the sides (duh), the bottom anywere, and the top sides. If I shoot in the top center it rips the aluminum so I can see in but the BB won't go through. Do you think that mabey the chrono at the place isn't working properly?

Well it is possible that the chrono may have been wrong... or maybe the battery was low or something.

I guess the best thing you could do is shoot it and see if the range is good... if so then dont really worry about it.

I guess this may be a dumb sounding question... and I am sorry if it sounds like I am doubting your airsoft knowledge, but are you sure you were shooting .20's over the Chrono?? It would have a drastic effect if you were using .23's, .25's, etc...

Just thought about this a second after I posted the last message.

I don't know what they used. But for the pop can I used .2's. And my effective range is 185 ft. (yes I measured and yes it took a long time)

I like using .2 bb's they get good accuracy and are pretty cheap too .

i would check to make sure everything is sealing properly.

unfortunately ive noticed that alot of people are having a very hard time upgrading their E1's or JG guns over 400. i first noticed with seabass then on Arnies and now you are the second person to some to this forum with this issue. IDK maybe the mechbox is warped a little. not too much because then it wouldent work but a minor warp would make it loose some considerable compression.

if you buy a bore up kit you should be getting the FPS that you want with your current spring. i would take it down to a M120-M130 if you do buy a bore up.

good luck

sticks

I am assuming that you have an m4 variant since you mentioned V2 spring guide with bearing.

1. is your cylinder compatible with the barrel length.? btw, what is the brand and model of your aeg?

2. Install an Air seal nozzle (this has an 0-ring inside, the stock ones do not have this) this gives and increas of about 20-25fps.

3. Is your cylinder head properly installed and secured? this means, it does not move easily. using the teflon or silicone fix will seal this area. Is there proper compression? maybe you need to change the piston head 0-ring

4. Does your m4 have a one pc metal hop assembly or a two pc plastic hop assembly? If the aeg is a China made aeg then there is a possibilty that the metal hop is not good (leaks) If you have a two pc hop, there is a certain fps loss on this but negligable. In both variants, your hop assembly maybe moving forward/is pushed fwd when installed thus creating a gap between the air nozzle and the hop assembly. (note that there is a small spring which is supposed to push back the hop assebly back towards the ASN. Some diy remedy is to replace the spring or put some material inserts in that area (eg pc of tape etc)

btw, I am assuming that the madbull m140 has the same rating as the systema m140 or the guarder SP140.. ( i prefer the guarder since new springs are usually rated higher when new, meaning an SP130 will shoot like an sp140 for several game days till it settles down).