Low FPS

[sam_G]

When i tried using my G&P MRP last night it would only manage 190 odd FPS. Then wouldn't feed very well.

Would this be down to a badly charged battery? It uses a 7.4 Lipo in the stock tube.

It worked fine the last time it was used and was hitting 300FPS with same battery.

Any advice would be great.

[johnnyj]

Re: Low FPS

sorry to say if the battery turned the gun over something is wrong , since it was not feeding I would look at the hop rubber for damage , if the hops fine while the upper is off just fire the gun and make sure the nozzle moves all correct and see if the piston goes all the way back.

[JOE90]

Re: Low FPS

Snapped nozzle? Spring missing from hop unit? Badly torn rubber? Spring from tappet plate come off?
Could be a host of things so it needs a good look over mate.

[sam_G]

Re: Low FPS

GREAT! I have no idea when it comes to working on these things.

[julesbloke]

Re: Low FPS

As the others have said, the battery has nothing to do with FPS.

I had a similar drop in FPS on one of my guns and it turned out the piston o-ring had snapped. So it could be anything from internals (piston, compression, tappet plate, nozzle) to hop and rubber etc. The easiest way is to start at the hop, take it apart and reassemble. Make sure the rubber and nub are OK. If that doesn't sort it then you're probably going to need to open the gearbox.

[sam_G]

Re: Low FPS

Just had a very limited look. This being the second time i have taken a gun apart was a very basic look. everything seems to be in place.

I will have a proper strip tonight once i dont have a very interested daughter trying to "assist" me!

Cheers for the help!

[sam_G]

Re: Low FPS

Now i have put it all together it feeds perfectly from the G&P mag i have but has issues with the others i have but seem to fire as strong as it did before. I backed the hop up off abit as i remembered i had moved it 2 clicks forward.

Will an air rifle chrono work on an airsoft rifle?

[JOE90]

Re: Low FPS

Yes mate it will, what one do you have? Run it throught the chrono and post results

[sam_G]

Re: Low FPS

I don't have one but my dad does in his armory.

Will be tested on Saturday.

[sam_G]

Re: Low FPS

Right had it all apart today with dads help. he has all manner of gun cleaning bits. Oiled, greased and cleaned everything. wound the hop back loads. put it all back together and tested it with the chrono and got results ranging from 230FPS to 305FPS and fed fine from the G&P midcap. forgot to take any of the others with me but will test it later.

Quite happy with result!

[sam_G]

Re: Low FPS

Have just used the plastic mids and put 900 rounds through it without a single miss feed!! fired flawlessly!

Am happy bunny about that but pissed off i sold my belt rig in haste to fund new mags i now don't need!

Must invest in some decent cleaning gear!

[spoon987]

Quite a bit of variance in those reading mate. Might be an idea, now that your familiar with your gun internals, to make sure you got a good air seal every where. From the piston head, cylinder head though to the hop unit. PTFE the shiz out of that thing!!!

[sam_G]

Re: Low FPS

305 was prior to adjusting the hop. it was constant around 258FPS.