A&K M4 Sight & Barrel Problems

[Liam Porter]

Edit: Didn't notice the AEG section, sorry. Any chance this could be moved?

Thanks.

I have the A&K M4 CQB-R, and since I got it, the barrel's been easy to twist, just a few degrees or so, but this makes it so I either have a perfectly lined up front & rear sight, but the hop up is slightly twisted, so the mag doesn't fit and the BBs go far left.. or, if I line up the hop up, then the front and rear sights are completely out, so I can't actually aim at anything..

I've managed to get the whole thing apart (finally, took some force just now, and I smacked myself in the face with it), and I noticed that the front sight doesn't quite sit on the barrel straight. If the barrel's lined up with the upper receiver, then the front sight's out, and if the front sight's lined up, then the barrel's not straight, so neither is the hop up.

I think it's the grooves on the barrel that aren't level from manufacturing. The two where the sight goes aren't quite level with where the barrel fits into the receiver or the hop-up. I've put the sight on perfectly level with the grooves and tightened it so it stays in place, and then put the barrel into the receiver, perfectly level here too, and tightened that. Then compared the sights and they're still not level!

Pictures; sorry it's hard to see the sights, but they're really bad when trying to aim.

Sights not aligned.

But the barrel is aligned properly.

So I line up the sights.

So now the barrel's about 1mm out. Excuse my yellow hand..

Which puts the hop-up 2mm out. It's hard to see, but it's quite far to the left.

This stops the magazine going in when the gun's together, and causes the BBs to fly off to the side quite badly.

Is there anything else it could be or I could try before I give up on this and put it back together?

And if not, will a new outer barrel solve the problem? And will any M4/M16 outer barrel fit the receiver, or does it have to be A&K specific?

Thanks.