Short bursts on SA mode

[yuri]

Hi to all. New member here. It is nice to have an opportunity such as this. On the forum I've found info that I never new before, thanks.
Now, finally, after I took my new Vector full size to the range, I know I've got something special. Let me tell you what that special is and ask you to help diagnose the problem. On A it will shoot as it suppose to, i. e. untill I release the trigger. On SA it might do one, two or three shots with one pull of the trigger. Any ideas? I think it will be informative for all the members to know what went wrong. I will keep you informed about Vector's thoughts.
Regards,
Yuri

 

[ecross27]

under powered ammo will definately cause a similar problem.

 

[yuri]

Thanks for replies, keep them coming.
I was shooting Winchester Q4318 124 gr FMG NATO ammo. Should I change it?
Buffer (that piece of plastic made for semi and used to increase rate in auto?), there is no one installed yet on my uzi.
Spring seems to be reasonable, but it is very subjective and I have not compared it to similar one on properly functioning uzi.
Do all 3: underpowered ammo, hard return spring, long buffer have similar mechanism of not allowing the bolt to recoil back far enough so sear is not able to catch it at the front bents (C2 in my operation manual)? Is it possible for the bolt in sa (R) mode to travel back under recoil not far enough for the sear to catch it, but still far enough to strip new round from the magazine and fire again, essentially making it a mode?
Regards,
Yuri

 

[amphibian]

I haven't tried that ammo but it sounds like it should be fine.
In addition to what the others said,
I would like to add to check to see if the sear is worn but that is doubtful since your Uzi is new.
Another thing to check is topcover play. If there is too much play between the topcover and the bolt, the bolt will have room to "jump" off the sear.
Where the topcover mounts to the Uzi behind the front sight, can you move it up/down? If so, you may want to bend it a little.
Here is a little tip:
Get yourself a feeler gauge.
Use the .005" and .015" gauges as your "go" "no-go" gauges.
If you can stick that .015" feeler gauge between the top of your bolt and topcover through the ejection port then you need to bend the front of the topcover a little as the bolt is most likely jumping off the sear.
Amphibian (Robert)