Nozzle position and fps consistency

[AlphaBear]

Model, TM recoil AEG, M4 variant, V2 gearbox.

Chaps, just a wee question. With regards to the air nozzle, when you fire the gun what position in the hop chamber should the nozzle return to. I'm looking at my hop unit and I see the front end of my nozzle protruding half way into it. I guess this makes sense else if the nozzle was fully retracted then bbs would just spill into the chamber right? Or have I screwed up my gearbox rebuild?

Second question, It's firing about 335-345 (yeah a 10 fps variation). Is that type of variation normal or should it only be a few fps between each shot?

 

[Adolf Hamster]

halfway sounds like just the point it's landing on the timing of semi, if you try bursts of full auto you should see it drop at different positions each time.

10fps is what i'd call borderline, ideally it's a value you want to be as low as you can physically get it to be. but there are a few factors that will cause it so it can be a tricky thing to get really low. it should be fieldable at that but could definately be better.

 

[AlphaBear]

I can confirm that my half way dropping is in semi for sure.... 

With regards to the fps, I'll check it again for leaks. I know my cylinder is the wrong one that's for sure as I accidentally bought a type A when I should have got a type C as my barrel length is 363mm.  Maybe the cylinder could be the culprit or perhaps I need teflon tape on my hop rubber? Mind you it's a firefly on a stainless steel pommy barrel snd I'm sure it was a tight fit when I last got it on... I'll do the usual checks again...I'm using Abbey silicon grease for my cylinder and the tub is about 6 yrs old. I don't think silicon grease goes off does it? Or shall I buy new stuff?

 

[Sitting Duck]

Hate the Type A, B, C etc... BS crap on cylinders....

if you can measure the damn thing, where the port starts from front of cylinder







but cylinder types & stating is a Type A or B for example varies a bit I have found

some call it a type B when it looks like what others might call a type C blah x 3

plus I've seen cylinder charts give out info on barrel suggestions that imho is wrong

measure the damn thing, take off a bit for cylinder head & a bit for compression to seal & build

then see if it looks about right - check it yourself than go by a letter assigned by somebody

 

[Rogerborg]

perhaps I need teflon tape on my hop rubber?

<Screams in Negative Airsoft>

If you've been lubing the cylinder, have you given it a blast to blow any gloop out (barrel off), and thoroughly cleaned the hop rubber and barrel?

 

[AlphaBear]

The barrel has been cleaned and firefly hop is fine (famous last words)... I was getting some odd readings earlier where the odd bb went as low as 310 but then back to 333 - 345.... I must be losing compression somewhere...? Here's a thought, could the spring be dodgy? Maybe it's not compressing and decompressing within the same tolerances? 

 

[AlphaBear]

So I took it apart yesterday, cleaned up the cylinder assembly and re-greased the whole lot... checked for leaks and zero! Took the hop apart, cleaned the buking and reseated it (firefly) oh and cleaned the barrel at the same time....

Then I got the chrono out...

F#ck me! it's doing 347-350 fps on 0.2 with hop off... Just the odd one doing 351fps. I'll stick another few hundred rounds through it to bed the hop back in. Oh on full hop it dropped to about 330 is that about right?