KWA M4 CQBR - Problem Opening Upper

[safx]

Fibre S-system? I thought the front
was completely a metal build?

[The Saint]

Since we're going into review mode now...

I don't trust stock AEG hopup sleeve, except maybe TM.

Anyways, I've come across one strange case with a KWA M4A1's inner barrel. The gun was maybe a couple thousand rounds old at the most, shooting quality BBs. For some reason, it developed a layer of BB residues around the mouth of the inner barrel, making hitting someone at 30' difficult. It was scraped off with a little effort and the gun performed normally afterwards.

[safx]

Originally Posted by The Saint

For some reason, it developed a layer of BB residues around the mouth of the inner barrel, making hitting someone at 30' difficult. It was scraped off with a little effort and the gun performed normally afterwards.

Well when some say they really "love" their gun
I guess they've expressed that in a fluid exchange
kind of way. Get your friend a lady for his bday
and not another gun

[m102404]

bad bio-bbs?

On one JG tha passed my way...the houp rubber was "fused" to the barrel...it left a black scummy residue and "peeled off", like a sticker. I suppose some petroleum based oil was in there.

I scrubbed down the barrel but there was still a black "stain" in the brass...the guy ended up switching to a tightbore later anyways.

[lowflyjet]

Thanks all. I've read about the hop-up unit and bucking and trying to replace them, which is why I'm trying to crack open the receiver. While trying to crack it open, it felt like there was another catch grabbing onto the upper. Guess I'll just have to try harder.

Agreed about the 4 outer barrel pins, outer barrel slid off while trying to install a new rail system (I don't like the old-style handguards either, plus like using a shorty VFG). Thank goodness the barrel's pretty solid.

Cheers all.