Devgru spring change

[SimonDJXC]

Hi,

I am running 0/28s and was wandering if anyone knows what spring would get me to about 300fps. I am currently at 250. Any recomendations?

 

[Colin Allen]

There are so many variables that it is almost impossible to say.  What spring is currently fitted?

 

[SimonDJXC]

i believe it was called an M something.... looking i think its the m100. next question is then will the mofset need upgrading as well?

 

[Hudson]

You don't want to beat 300 on 0.28s.

The 1.14J limit will be approximately 295fps.

Rather than opening the gearbox and swapping the spring, you'll probably be better off ensuring you have a good air seal, as well as bucking & barrel which should get you to what you want.

 

[SimonDJXC]

how do you ensure a good seal?

 

[Hudson]

Good bucking and barrel and ensuring it's all in place properly and snugly in the hop unit to start with, after that it means opening the gearbox up and getting good air nozzle/cylinder etc. parts

 

[Colin Allen]

i believe it was called an M something.... looking i think its the m100. next question is then will the mofset need upgrading as well?

Click to shrink...

You need to get it up to about 280-290 fps (300 is hot!), which is a considerable increase and, if the current spring is an M100, is going to need at least an M110 spring.  However, assuming that the barrel and cylinder are properly matched, you may well have a poor air seal, which you would be well advised to sort out.  Give the inner barrel a good clean with isopropyl alcohol as well.

You don’t need to upgrade the mosfet just because you install a stronger spring.

 

[Galvatron]

next question is then will the mofset need upgrading as well?

Click to shrink...

What feature do you think your current one is lacking that you need to upgrade it? 

 

[SimonDJXC]

i dont, just watching dissasembly videos doesnt seem to hard. I will try .25s first. can you identify which barrel and cylinder we are talking about? definatly something i want to check. 

 

[Galvatron]

For the sake of clarity, can you confirm which gun you are talking about?

Are you talking about the TM 416 DEVGRU NGRS or another RIF that has DEVGRU in its name?

One troubleshooting tip is checking the compression in your cylinder - if you put your thumb over the nozzle while pressing the piston into the cylinder, a sign of good compression is that you will eventually get resistance against pushing the piston. If you get no resistance and you piston goes all the way down despite your thumb being in place over the nozzle, you've likely got a compromised seal, which would explain why your muzzle energy is much lower than expected with an M100 spring. Your piston head and/or its O-rings may be the culprit is your compression is poor.

 

[Colin Allen]

For the sake of clarity, can you confirm which gun you are talking about?

Are you talking about the TM 416 DEVGRU NGRS or another RIF that has DEVGRU in its name?

One troubleshooting tip is checking the compression in your cylinder - if you put your thumb over the nozzle while pressing the piston into the cylinder, a sign of good compression is that you will eventually get resistance against pushing the piston. If you get no resistance and you piston goes all the way down despite your thumb being in place over the nozzle, you've likely got a compromised seal, which would explain why your muzzle energy is much lower than expected with an M100 spring. Your piston head and/or its O-rings may be the culprit is your compression is poor.

Click to shrink...

And/or the cylinder head O ring(s) and the seal of the nozzle to the air tube.

 

[SimonDJXC]

Yes TM 416 Devgru. Ok thanks will give that a try!