CM16 not feeding BBs after bucking change.

[Reef]

I know there’s a few threads on this kind of issue but I can’t find one with my specific issue.

 

I took my CM16 apart to replace the bucking rubber (same green rubber). When I put it back together it worked perfectly and felt really nice. When getting the rifle crono’d on Saturday the magazine wouldn’t lock in. I tried 3-4 different mags, mid, high caps with the same result. I took it apart, checked everything about 15 times with no improvement. 
When I got home I took it apart and this time managed to get the mag to lock, but now it only feeds one or two BB’s before nothing.

Inside the CM16 it’s simple, so it’s really bugging me that I can’t see what’s wrong. Any ideas?

it must be an alignment issue but I can’t see from where, what have I done wrong?

 

thanks in advance.

 

Dave

[The_Lord_Poncho]

If you have installed a like for like replacement G&G green bucking, then that rules that one out. But in my view the fact that the mags are no longer locking in place indicates that the failure to feed is unlikely to be down to the bucking lips being e.g. longer, but rather that the hop unit isn't sitting where it was previously - which you have probably worked out already. I presume that you are confident that the spring that was either around the inner barrel in front of the hop unit or the little bendy spring that is attached to the front top part of the hop unit were reinstalled (I’m not sure which design your hop unit has, but I presume that it is one of those two options)? This keeps the hop unit pushed back onto the front face of the gear box. The upper receiver is fully located as far back as it should be on the lower receiver, and the front retaining pin was able to be inserted with the similar level of friction as when it was first removed? You didn't take the opportunity to do a few wraps of tape around the inner barrel, which if overdone might somehow be preventing the inner barrel and hop unit sitting where they previously were inside the outer barrel? If it's none of those, then I’m out of ideas!

[Reef]

Ohh, that's a really good point. The clip that goes around the hop up unit to hold the barrel is sitting a little bit higher than it was before. Its only a miniscule amount but I wonder if that's enough friction to work against the barrel spring to stop the unit seating in the exact same place. I didn't make any changes like adding tape so can rule that out. 

I'll try again when I get back from work tonight.

Thanks for responding.