WETTI/AWSS - M4/SCAR/HK416 - Technical Summary Thread

[Shirley]

lol that spacer aligns your nozzle to the cyinder.. Maybe that's why it mushed?

[Thenooblord]

dont see how it would do that, it doesnt touch the cylinder, it just keeps the nozzle away from the bolt a bit further...

[Thenooblord]

I now just put the spare valve spring on the rod where the spacer went, just to see what it does, maybe better airseal? ;p

[m102404]

Originally Posted by Mr.Hitman

lol that spacer aligns your nozzle to the cyinder.. Maybe that's why it mushed?

That's incorrect. That spacer "spaces" out the nozzle to the correct length so that it seats fully into the chamber and creates a seal. Without it the nozzle might not seat fully, or might blow back prematurely creating a leak.

If the spacer is too long...you will definitely crush your nozzle (that's why it's a bad ideal to keep shooting when you've got a bad jam as well).

If it's not there, it's unlikely that's the cause of the crushed nozzle.

The SCAR nozzle is aligned by the e-clip that secures it to the bolt. The flanges on the bolt are weak...and if they deform, the nozzle will go out of line and hit the cylinder with every shot. (I'd bet $1 that Noob's piston body is all deformed at the rear flange)

Yours was deformed too...but I wacked it back into shape when I swapped in the adjustable nozzle the other night.

Shelledpants was tweaked as well when I took his apart.

Originally Posted by Thenooblord

I now just put the spare valve spring on the rod where the spacer went, just to see what it does, maybe better airseal? ;p

The weak little spring from the nozzle? That's too soft. Try a stiffer spring...the "crush" dimensions of the scar setup are very small (I think it's 2-3mm...can't remember off hand). If you put a spring in there, be sure that it "crushes" to that size or less while still exerting significant expansion force or you'll stress the other nozzle. If it's not exerting enough force...then it might give when you shoot a BB (when there's back pressure...there's no back pressure if you're dry firing) and the nozzle might set back, resulting in a leak.

Are you sure you should keep destroying this gun...it's not going to be worth anything by the time you're done with it.

[Thenooblord]

Originally Posted by m102404

Are you sure you should keep destroying this gun...it's not going to be worth anything by the time you're done with it.

ehhh, passes the time...

[Thenooblord]

I just smushed another nozzle.. guys, what do i gotta do to fix this? this is pissing me off, and nozzles are expensive
this one is still "useable" so Id like to save it

[808]

Firstly, step away from the gun. Don't hurt her any more.

Secondly, at this point, you should detail what your installation steps are in case you've missed anything.

[Thenooblord]

not sure what you mean by that
put nozzle in bolt, put bolt in gun, shoot a target, remove destroyed nozzle

[Shirley]

Have you even loctite the nozzle onto the rod? Maybe you're shooting it, it comes too loose and BAM, crushed.
It could be your magazine feed lip too. Check your inner barrel if it's on and not blocking the way?

[m102404]

There's obviously (now it's obvious...sorry for your luck) something wrong in the setup. Not necessarily a "trying to fit tab A into slot B" problem, but there's some kind of tolerance thing involved.

Another odd ball kind of thing that could be happening...
- the chamber that you're using may not allow the nozzle to seat properly...even if you've got the overall length ok.

If you let the bolt go forward slowly/gently by hand...does it seat fully?

Anyways...if you're just guessing at things, better off to get it to someone who might be able to make better sense of it.

Or ruin it completely...I'll buy it cheap for parts afterwards... (just kidding)

[Thenooblord]

the only binding i find is that the large oring never seems to get lube, so it gets frozen and sticks

the only thing that is different from stock now is the valve in the nozzle, its got stock nozzle, stock cylinder, and I didnt have these issues before

you fix it tyson!
lol

[m102404]

Break out a big handful of $$$ and book a time with me. I'm technically out of the gun doc stuff now...but these things are neat so it's at least interesting to work on.

[Thenooblord]

how big a handful, lol

[808]

If the "big o-ring" is sticking - then that's what's causing it to break the nozzle.

It's likely at this point that your cylinder is bent/damaged and will need to be re-aligned or replaced.

But again - take this info with a grain of salt, as I'm just trying to do this with a mental picture.

[Thenooblord]

any1 got spare nozzle assermbly?