Cocker blowback

[Seejay]

Hey guys, how do i stop blowback on a cocker? it's an E1 frame with:

SON = 3
CDEL = 3
CON = 60
CTO = 255
COFF = 28

Anything i need to lower/raise to eliminate blowback?

if not the electronics, then what is it?

Thanks, Chris

 

[Gyroscope]

Your CDEL is likely too low.

Do this:

Stretch a piece of balloon over your feedneck. With the gun gassed up, try raising the CDEL one millisecond at a time until the balloon stops raising up like a little bubble. You don't want it too tight, or the air won't bulge the balloon. You can also place over the feedneck a piece of thin paper, a bit of plastic grocery bag (if you have those in the EU), or if you are samurai, a piece of the finest silk. When the blowback stops, the membrane should not pop up anymore.

There is a semi mystical quality to some cockers around 6-9 CDEL where the membrane will actually suck down into the feedneck. If you can tune it like that, feeding should be infinitesimally more reliable. I did, but I am a nerd like that.

 

[Skeet]

If you have QEV's and a 44 or Nexus ram, you need to have teh CDEL at around 006 milliseconds.
Reason you get blowback, is that when you fire the gun, with a short CDEL, the bolt starts moving back, before the gun has finished cycling and firing teh ball..so excess gas pops up teh feedtube.

It could of course just be bolt o-rings.
Try the test as Gyroscope said, but hold teh back block in (drop your CON time loads).

 

[Gyroscope]

Teh point Skeet raises is a good one- I didn't think of teh bolt o-rings.

 

[Seejay]

hey guys, it's been fixed now, i just heightened the CDEL to something like 8, now it has a slight suction

Thanks for the help Guys,

Chris

 

[Skeet]

See...we knows best.

 

[Seejay]

and that Just could be the reason i asked you guys

Chris

 

[Seejay]

Whilst mildly on the subject of re-timing, i have a question about the E1 'noid. What the hell is that little orange button inder the 'noid for? it's bugged me ever since i noticed it there.....

Chris

 

[Skeet]

You can use it to manually cycle the noid...you have to push hard tho.
If you suspect an electrical problem, you can use that to prove teh noid fucnctions, which means the wiring to it is faulty..

 

[Seejay]

ah, thanks