MP5 feeding issue?

[Tenn870]

So I took my zenith ZF-5 to the range yesterday and shot about 100 rounds of blazer 115 grain, I had a dead air ghost 45 on it. I had 3 failures where the round would jam and the bullet was pushed into the case (see photos). I did not switch ammo and only had 1 mag on me. Any thoughts on what could be causing the issue?

 

[outrider58]

I'm not fluent in things MP5, but there definitely appears to be deformation on the tip of that bullet.

 

[Tenn870]

I'm not fluent in things MP5, but there definitely appears to be deformation on the tip of that bullet.

All of the rounds that did this had a slight deformation from where the bolt jammed it into the feed ramp (I think)

 

[outrider58]

All of the rounds that did this had a slight deformation from where the bolt jammed it into the feed ramp (I think)

Someone will probably ask what mag you were using.

 

[Squaregrouper]

Someone will probably ask what mag you were using.

Until 2020, Zenith "MP5's" were made by MKE in Turkey. The MKE's are now imported by Century Arms as the AP5, which I have. (Zeniths prior to 2020 are the same as an AP5, just different importers)
My AP5 does something similar with hollow points- especially wide face HP's like a HST or GD. Others here haven't had the issue and it has been stated multiple times to try an actual H&K factory mag to make the problem go away. I have not gotten my hands on an actual H&K mag to confirm or deny this.

 

[guzma393]

My century arms ap5 runs reliably with 124 grain and 147 grain subs, can or no can. It hiccups a bit on 115, even after doing the "1000 round break in with 124 grain 9mm" century arms recommends. Myns absolutely hates fp's and hp's therefore just run strictly round nosed ammo.

 

[ken792]

Try an FMJ. I wonder if the plated bullet on the Blazer is soft enough to deform against the chamber and stick rather than skid past on the way in.

But yes, try it with H&K mags to eliminate a variable. Another variable to try would be to swap in an H&K Action 3 or F bolt.

 

[Hoons]

My zenith mp5 does this with hollow points. FMJ works fine

 

[4g64loser]

Assuming that your gun is in spec, this is probably a magazine and/or weak ammo issue. As other posters have said this weapon design doesn't usually like wide meplats. I have never used plated bullets in an mp5 but I can say that bare lead is a no go both in my personal sbr and several post 86 dealer samples. Bullet weight has been less relevant in A2/A3 guns. Have run tens of thousands of wolf 115 out of dealer samples and it's great. Almost any of the Czech or Serbian stuff runs well. It's all full CIP spec, whether 115 or 124. Winchester white box is a no go, typically loaded weaker than bud light I'll dig up the chrono data if anyone really cares.

The projectile is a part of the feed cycle and needs to be close to the correct profile for proper feed. They contact the trunnion coming out of the magazine.

If you guys want to try real mags and don't mind a drive, pm me. I have SD marked crenelated front straight bodies and a couple of the curved bodies. Straights seem best across all the mp5 variants that I have access to but ymmv.

 

[pistolsnipe]

Worth checking the extractor spring just to make sure, those have been known to cause issues.

 

[Rockzilla]

Try "HK" mags, it may prevent the issues, as 4g64loser mention also if the ammo is not consistent, you will have issues, loads too light and is the gun in "Spec", the MP5 built here on a HK parts kit (LSC flat) has had none of these issues, now, using HK mags, haven't tried any others so don't know and can not comment

-Rock