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Discussion Starter #1
I had numerous failures to eject with new MP5 (2-3 times per 30rd mag).
No obvious reason I can tell (ammo 124 FMJ Federal factory ammo); field stripping at the range revealed nothing apparently wrong - intact extractor, extractor spring etc. Brass was very crimpled - a photo of some casings is attached...
Any suggestions?
Thank you,
 

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Are you using a plastic lower? If so, check for play where it sits on the receiver shelf. It should fit tight on the receiver with no play. Any downward movement there can change the angle of ejection and cause those types of failures.
 

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Discussion Starter #3
I am using plastic SEF pack in MP5 N setup. SBR was built by Dyer on HK94 and sear is by Flemming. Appreciate the suggestion but there is no play between lower and receiver...
 

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Has it been doing this long, or just recently?
You may want to try different ammo brands and bullet weights. Double check that extractor and spring.
 

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Discussion Starter #5
First time to the range since the purchase (I have bought SBR and sear in plastic SEF separately)
In addition to Federal Eagle I have used Winchester 124 grain FMJ today with exactly same results (2-3 FTE per mag)
 

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First, I would check the bolt gap before you blow it up like I did with my first MP5. Do not assume it is correct. If it is wrong, the bolt or the carrier or both (as in my case) will break. If the gap is ok, proceed. Every Failure to Feed of Failure to Eject in my MP5 I ever had turned out to be an ammo problem. Mine runs on S&B 115g. or Remmington 147G. Subsonic. I have never found a 124g. that would run. I am not saying that they all won't. It just seems that MP5s and HK53s are more ammo sensitive that the long guns when you go full auto. Try a lighter bullet at at faster speed. On some of the ammo sites like outdoormarksman.com, they have specs on different factory ammo. Find one that it likes and stick with it. I think that Winchester White in 9MM/115g is pretty hot. Can you find out from the previous owner what ammo he ran in it or from Terry what he tests his MP5s with?
 

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Would check where the ejector is hitting the case.

Check if there is any movement with finger pressure of the extractor, then remove the extractor to clean (possible even needing careful use of a probe to clean the extractor grove) and at the same time check that the extractor spring double wire shaft is straight.

Would check the ejector face, make sure the ejector spring is there and of course have the correct ejector in place.

Plus as the previous poster recommended, check bolt gap.

After trying different ammo, one is nearing the point of swapping parts, getting the layout die out to see where everything is hitting or returning for professional help.

P.S. Have a couple MP5s from Terry and they run 124gr NATO nicely for many thousands of rounds.
 

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Discussion Starter #8
Thank you Guys,
Bolt gap was checked and within specs (40) before I proceeded with any shooting. At this point the gun went to gunsmith for further diagnostic check - I will keep you updated...
 

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Let the smith check it out. An MP5 is not ammo sensitive. I have yet to find any ammo that won't work in my MP5 in full auto....Most likely the trigger pack in relation to the upper that needs a little tune up. Maybe someone did not put the trigger pack together correctly also. Did you shoot the tirgger pack in any other gun?
 

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Discussion Starter #10
The only full auto host I have is MP5 in question. Hopefully more to come soon...
 

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My MP5 did the same thing with the cases looking like yours. I had changed the ejector to shoot it in my HK53. I had put another ejector in without looking. For some reason, it failed to work. I put the one that came in the pack back in and it has run ever since. When I compared the 2 ejectors, the one that came with the pack had a small hump on the top of it that seems to push it down further than the stock one from a 94 without one.
 

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Discussion Starter #12
Appreciate your info Spotter. At this point I am waiting for gunsmith opinion...
I suspect some adjustment either in the whole lower or may be in the triggerpack or ejector may be in order. Will share final results when available,
Sincerely,
 

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Discussion Starter #13
Problem was fixed by replacing extractor and extractor spring...
Not quite sure what was wrong with either one since they were looking normal to me...
Anyhow MP 5 ate 400 rounds today without a single hiccup!
Thank you again to all of you for looking,
 

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I'm surprised it took so long to find an answer. My class III dealer has been shooting MP5's for 25+ years ans he said the extractor spring is the only thing he's ever seen break. The only other issue was using crappy ammo, which I can attest to. My MP5 will FTE on that yellow box Remington UMC stuff. I've heard it's because it's "low impulse"
 
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