Urgent G&G GR25 DMR help

[desolation91]

Right guys i swapped my mint scar for a g&g gr25 and ive had nothing but problems, not going into that now i will once its fixed!

Anyway i have put a m130 in there and its only giving me 320 fps Something isnt right. It also doesnt sound right.

Ive replaced all the internals, gears, new nozzle, piston, piston head, motor etc

[emergencychimp]

Re: Urgent G&G GR25 DMR help

Have you changed the barrel? Do you have a ported or non ported cylinder? How long is the barrel? Have you check the seal on the piston head, cylinder and cylinder head?

Either, you have a terrible seal some where(or multiple places) and you're pissing air or you have the wrong ported cylinder for the length of barrel you have. Eg a ported cylinder and a massively long barrel or a standard cylinder for a short barrel.

[desolation91]

Re: Urgent G&G GR25 DMR help

I have a 509mm tight bore with a non ported barrel.

The seal on the cylender is ok its not solid to push the piston in there is some resistance

[sj_asc]

Re: Urgent G&G GR25 DMR help

Try the hop chamber leak test - you will be able to feel air leaking from feed nozzle, a small piece of paper usually helps.

What exactly have you changed? Do you have a list of parts?

[desolation91]

Re: Urgent G&G GR25 DMR help

How do i do that mate?

There is
Shs 32 gears
Hurricane aluminium piston
Plastic Vented piston head
M130
New g&g gr25 nozzle
Ultimate hard rubber
6.03 barrel
High torque motor
New cut off leaver

[colinjallen]

Re: Urgent G&G GR25 DMR help

Turn the gun upside down and put a small piece of paper covering the feed nozzle. Shoot the gun in semi and see what the piece of paper does; if it just flickers a tiny bit, your hop chamber has a tight seal with the air nozzle. If it is puffed around, there is a bad seal.

[desolation91]

Re: Urgent G&G GR25 DMR help

Little update... Ive had to. Order a cylinder head, piston, spring and sorbo lad..
Opened it up to Start checking compression and found this

[emergencychimp]

Re: Urgent G&G GR25 DMR help

yeah, that looks like it would do it!

Hope that sorts your issue

[call of legend]

Re: Urgent G&G GR25 DMR help

Not the first time I have seen that happen in a G&G sr25

[desolation91]

Re: Urgent G&G GR25 DMR help

Not the first time I have seen that happen in a G&G sr25

How did they fix it?

[call of legend]

Re: Urgent G&G GR25 DMR help

I believe they changed the piston to a reinforced one and improved the angle of engagement on the gears with the piston however it has been a good couple years since I talked with the owner of the gun about it so I might be incorrect on how he fixed it

[desolation91]

Re: Urgent G&G GR25 DMR help

im happy as long as its fixable haha, i just need to figure out how to.. hopefully the parts will be here tomorrow

[call of legend]

Re: Urgent G&G GR25 DMR help

I can ask the person tomorrow for ya and ask how they fixed it.

[desolation91]

Re: Urgent G&G GR25 DMR help

that would be really helpful thank you

[desolation91]

Re: Urgent G&G GR25 DMR help

ok so a little update, fitted new m130 spring, piston, cylinder head and corrected the aoe,

put the gun together and tested, 325 fps... WTF! so tried a few times and still the same,

i took the tight bore out and put original barrel and another hop rubber in.... still 325 fps.

so i took it apart again and noticed it was catching the last tooth on the piston again, so i took a bit of the spring guide off (it was a bearing one and had a part of the bearing left) and then fitted a new m140 spring. put the gun together and fired it at 325fps!!!!! the thing is i have had this gun shooting at 450 fps! but i cant seem to get it back up to that