Nothing but problems with my Custom G&P M4

[Sitting Duck]

Okay so when firing, it:

A: Jams

B: Makes a weird soft thump noise

C: Fires very slowly

a - jams - gonna guess that is likely hop area

b - soft thump noise - didn't quite hear it but that clicky bit in 2nd vid where it stops firing then works again

sounds like a dead zone

c - fires slowly - you gotta be kidding in that first vid link

I presume you are running on 11.1v still which is still pushing that mofo especially if the 11.1v is a 25c burst

if you have a 7.4v and turn off active braking on 7.4v

Get the gun working first - feeding and chrono on 7.4v which should give you a rof at about 25-27rps on bearings

if you can turn off AB etc....

It is a case of NOT trying to run before you can walk

eg: 25rps say on 7.4v, mags should feed no problem chamber bb's test on semi & chrono & full auto

you need to know what the gun is shooting at roughly too - heck roll a bb down barrel from the other end

yes this bb will sit other side of bucking and therfore nigh on no hop on so it will be higher than usual

but if you are really out on fps and low/high

I'm gonna do a VERY VERY rough guess and say with hop off or a bb down the end of barrel rolled back to bucking you should get about 375fps

but this is just a guess

if that bb - and you may have to do this a few times

if that bb comes out at 300fps then you got a problem

run the gun at MODERATE speed first to test it

you may have feed problems above 30rps - could be mags/bucking

the faster a gun cycles the closer to perfection everything has to be - and I mean everything

stock guns will feed a lot better at 15rps unless it really is f*cked

30rps things have to pretty good - not all mags feed above this

45rps yeah you will need it absolutely perfect and deffo not all mags will feed well

seriously - a sweet mag that feeds great on a 25rps means jack $hit when you start going faster n faster

same goes for bucking/nozzle chambering etc.....

The gun should be tested on 7.4v first see how it runs

then get an idea of how fast she shoots and what fps

Trust me above 35rps which you might hit you can still smash f*ck out of that gun getting close to PE etc....

Your shs torque should be pulling that thing very well - you shouldn't need too much AB on semi

but AB will not save your gun from smashing PE on full auto @ 40+rps

the brake only kicks in when you release trigger - yes it will stop the semi asap but not be braking until you release trigger on full auto like the clappers

However - I think but don't know if there are any special features or delay on each cycle to keep the rof at say a max 35rps

but that is getting ahead of things for now........

What you need to do is ease up a sec - test the gun on 7.4v 25c aprox

13:1 should get you about 26rps on bearings @ say 340fps - rough estimation btw..... but with a shs torque

(speed motor - 30rps but that can get hot)

so test the gun is mild modest stages

believe me I've done a couple of same gun model's upgrades and the first one was a nightmare or very least a learning curve

a d-boys one & a china gun - jeez the first ones were a major throw it against the wall bastid

but the second time I did it - it was a breeze working as it should or better

There is still an element of luck as well as skill/care & attention

just go easy on the juice for now and get her working on 7.4v first before you crank up the juice

see if you can get the feeding issue solved first and go from there in small stages

 

[Katana]

It was the hop up.

The ProWin just doesn't like the body of my gun or the nozzle

Throw the G&P inside and it works like a charm.

Feeding is perfect, even on automatic

Hop up is working fine

Haven't tested to see if I still have that problem where I fill a mag and fire and it fires badly on the first 30ish shots

Ill look tomorrow because it was dark out

BB's are getting hopped fine and all

I teflon taped the hop up lock and where the barrel comes out from the hop up

I threw an O-ring over the teflon to lock that mother down for good measure

I am getting into more of a sprint aren't I :lol:

The ROF is ridiculous

It's definitely over 30rps when I compare it to Youtube videos (Bad comparison I know)

I think it's about 35 because looking at the 40rps videos it's just a hair under that

c - fires slowly - you gotta be kidding in that first vid link

Sorry I meant that when I fired with the ProWin, the fps of the bb's was insanely low. :lol: :lol: :lol:

I'm quite contempt with the speed hahaha

I never really use auto much anyway besides suppressing

The trigger response is what I was after more than anything because I practically rape semi-auto

I do use 11.1v 25C batteriesand about that

Quick question: I switched from a 7.4v 20c to a 25c and noticed an increase in ROF and Trigger response

If I raise my c rating higher, will it raise my ROF or will the amount of current reach a point where it will stop increasing ROF because it has reached its "current potential"?

Anyway, I can program the MOSFET to reduce the ROF to whatever I want it set to.

Not exact but it is percentage based varying in increments of 10%.

Is it wise for me to reduce ROF then?

The soft thump noise I was hearing was referring to the strawberry JAM

I should of clarified on that rather than randomly saying a soft thump :blink:

ATM the gun is...working.

Now the question is...what is the FPS when chrono'd?

I can pray below 350fps, I mean I guess it's possible but something tells me that it's gonna be over

You say 375fps...I hope not :lol: :lol:

 

[Sitting Duck]

I said 375 if you rolled a bb from the end of barrel as you was having feed problems....

the bb will roll down to nub but sit the other side of it

so when you fire there will be no drag or backspin being created so no reduction in fps

eg: normally a hop wound on/off can be a 30-40fps difference depending on hop & bb weight used

so a 375 with no hop will drp to 340fps on a normal bb with hop so to speak.....

again a rough guide but you was getting jams you said so was only suggesting this to get a bb shooting out and maybe to get a rough reading....

so once you got your hop set - tilt gun to its side and bb should curve left/right on its side a bit to easily prove hop working

set ya hop to your weight - 0.25 say

then chron on 0.20's or hopefully 310-ish on 0.25's "should" be under 350fps on 0.20's

YES the C or burst rating makes a difference

normally 15c is well lame for tweaked guns - ok for stock but I wouldn't suggest buying a 15c to anybody unless you have no choice on a tight battery space gun - stock tube lipo's don't give you many options for choice but at LEAST go for a 20c or 25c if you can

30c maybe but as the C rate increases you get more punch and the response/rps creeps up a bit too

However - please be careful when upping the juice - trust me SS 3 teeth doesn't mean a 350fps gun will deffo like 40rps

You are sailing close to the wind and even when I have swiss cheesed like hell keeping weight below 20gms on a full complete piston

It doesn't mean a lightened piston will return in plenty of time to avoid PE

Well it has smashed on a 30sec auto burst nudging 40rps

(I'd rather smash it at home than on the field even though I wouldn't go that nutz - if it is likely to bust I'd rather know now that at weekend)

Yes you may be ok on semi with AB n stuff but all the same be careful going too nutz is what I'm trying to say

Most of us on here settle for a modest 25rps which can be easily achieved on 7.4v or 9.6v

The difference once you go past 30rps isn't really that noticable and tbh no response/rof past that will make up for a player/teams skill or gun's/players's accuracy

Plus there is a trade off where reliability in feeding with present mid range mags & reliability of the gun or durability

unless you wanna buy better more expensive mags and that one iffy component failing quicker etc......

RPS is only ever a guide - this is effected by motor - gears - spring as well as the volts/burst (I just refer to this a juice and be done with it)

You would be wise in getting gun to fire at around 24rps on 7.4v 25c and then around 36rps on a 11.1v 25c

you can set the delay a little lower to ensure you don't go past 35rps

I'd advise keeping to 30-35 no more - ffs would you really notice that 5rps off of 40rps ???

metal racks don't give you any weak point in drivechain like a half+half piston rack does

if PE takes place then everything is metal and so anything or numerous things can crunch

at pinion-bevel/spur can go as well as piston - so really consider this before going too nutz

11.1v's can only drop to 9v = 3v per cell

on a 7.4v you really really notice the juice dropping to 6v

on 11.1v not quite so much so change batteries at lunchtime

do not use 30c - I've used a titchy 33c block 11.1v lipo to test and jeez she really ramps up - whixh is why I break a fair few guns

normally I run 7.4v 25c on a 25-27rps gun

yeah weird the hop units - some work great and some are just crap for some people......

if you are over the fps then I guess you can remove spring guide or piston bearings

or try the old spring as your fps was quite low so could have been an old spring or mis-labelled one ?

also a shorter spring say 150mm in length is very easy to install

compared to a newer spring say 180mm in length

but I have noticed them shorter springs that install easy can overspin more even at mild 22rps on a m100/105 rated spring

(probably something to do with little initial resistance on milder springs like m100)

so yup - it is a good thing I feel to have a spring of a decent length than an easy to fit one if you are going to want a responsive/snappy gun

you still ain't out the woods yet, get her firing, chrono'd, feeding great, tidy wiring etc....

then you still got to get her shooting straight with some accuracy - this area I'm not so experienced

breaking guns - yup I've done plenty....

improving accuracy - ah yeah I still use cheapo guns so I can blame the gun still than my lack of hop/bucking skills

 

[Katana]

I use a mixture of mid caps but will be switching to mag brand mid caps because...they're awesome.

They completely empty rather than a few left behind like the G&P ones

No follower that sticks out of the magazine meaning you can break it really easily

Their design is so basic

They are made of really light yet rock hard plastic. I can drop these things all day on concrete honestly.

I'll stick to 11.1v 25c batteries because I love the snap to em.

However, I will reduce my rps to around 28? Somewhere around there

There is no point in my eyes in having an rps where I have it, especially if it's gonna start snapping all kinds of shit up

I'll pop in to my local shop soon and get chrono'd

See if I'm rocking close to the limit

It's weird how my opinions of fps have changed drastically

Started airsoft thinking fps = range like everyone

Learnt that the hop up assembly is most important for range and accuracy

But then you eventually go back to fps = range once that's fully upgraded

I used to run my gun at around 280fps with a 0.2 and fuck me I'm never doing that again

A squad was in column about 25metres away from me and I was using 0.25g bbs.

They literally heard the shot, saw me and moved before my bb's even reached them

I couldn't hit any of them

It was ridiculous

Now I aim for about 335-340 just incase of variations like weather and such that do some weird fps things to me

I've tried absolutely loads of barrels and absolutely loads of buckings. I mean like 10+ of each for the bucking

and at least 8 different brands of barrels

Settled on what I have now: Prommy TB, G&G green (flathopped) and flat prommy nub

I even tried the RHOP but holy crap that thing is delicate

No luck after 3 attempts...because it was the sand papers fault and the clamps fault and the....

The gun itself is actually half of the noise it was before

I'm still having counselling over that shimming job

It was like they didn't even try

They literally went faaak it and threw on some random shims. It sounds so smooth and soft now.

i sanded down the pistol grip so it fit the receiver a bit better because there was a massive gap, like quite substantial

As I said before, I definitely got a lemon but there is still some of the gearbox showing in the upper corner of the pistol grip

Need to shave some more.

 

[Katana]

So finally after some time I get around to playing a game day. Gun shoots insane. Amazing range and accuracy and I was overjoyed until I touched the chrono.

Shots read:

370

369

371

369

370

370

371

So very very consistent and no problems where about 30 rounds would lose compression which is good.

Site limit is 350.....oh shit me.

It's okay though because I now know what I'm doing somewhat with a gearbox so I open her up on site and trim the spring about 3 coils ish or maybe 2 and a half and bent the spring back flat as someone told me that not doing so may turn the piston on its side when firing (Sort of makes sense I guess)

In the process I lose the anti-reversal latch spring (MOTHER******) but I have active breaking so I can get through the day without an anti-reversal latch but the motor might not like it too much.

Go to fire and realise the trigger trolley spring slipped off. (MOTHER******)

Open her up again and put it back on and all that and she shoots.

Chrono.....

349

350

351

350

349

348

And eventually settled just under the 350fps mark. NOICE Played from after lunch til the end of the day no problems.....besides the battery setup.

Literally ran ghetto wires and mosfet on the outside of my stock

Duct taped it all to avoid the rain because the extension cord someone made so I could run an external battery pack was shockingly badly made and worn to hell but didn't think it looked that bad because the shrink was all nicely done. Nice on the outside, in bits on the inside.

I then remembered something. Clipping the spring now has put it at a lower power of course but that leaves me open to pre-engagement of the piston if I run it at 35rps and I did because I wanted to see the accuracy and range of the bb's when running such a high rps (Not that bad if I'm honest). I didn't use it during the games that much at all because I never really touch semi but I'll be sure to set it back to the 20ish rps mark when I next use it.

I am without a doubt getting the new spectre mosfet when it hits consumers by the end of this year. I'll run the gate mosfet setup in a separate gearbox in a separate lower body so that if my main goes down...I have a backup lower rather than a whole other gun.

Thanks for everyone's input and help...much appreciated.

Something I did change because I noticed my wiring chewing on the motor insert again was route both wires down the same side....works absolutely fine and no hungry motor wanting to eat red things.