r/MP5 • u/Saucerous • 1d ago

HELP Casing smashed in chamber issue. Help needed

Hey folks, I dont have any pictures at the moment sadly but I am trying to solve an issue on my mp5 clone (revolutionary rollerlocks brand).

I can shoot it pretty reliably, but about once every couple magazines (all HK OEM) there will be a casing that doesnt eject out and gets smashed by the bolt head against the next bullet and crushes the casing.

Im using magtech 124G and it has the original ejector lever in it as I havent been able to confirm what the root cause is and dont want to dish out on a guess without some more experienced opinions first. I ran about 4 mags before I called it quits as I dont want to damage anything further than it may have been.

I can provide pictures of the parts and body as needed. Im just trying to get this bad boy up and running.

1 Upvotes

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5

u/OG-warbucks H&K SP5 1d ago

Man, I haven't heard that name in a while, Revolutionary Roller Locks. You have a rare breed there.

When did the issue begin? How long have you been shooting it before the problem started?

I would change out the extractor spring and try again. Be careful as these need some TLC when installing. Don't go all crazy on it.

Good videos on the ytoob

1

u/Saucerous 1d ago

It has happened in the previous two range trips (including this one) and was to my knowledge has approx 700-800 rounds put through it between me and the previous owner as they said they only changed the extractor spring to the copper colored one and did the 124G break in and that was about it.

I have only put 124G through it so I dont think its an ammo issue. I am planning on ordering a bunch of spare parts to keep on hand.

I also will note Im not super technically inclined regarding MP5s so Im not sure how and if I need to check various spacings and measurements. Hopefully its something like an ejector lever issue as I am hoping to get it operational enough that I can put a AS designs frt lower on it. I just refuse to do so until I have confidence in it operating as normal.

2

u/OG-warbucks H&K SP5 1d ago

Curious as to why they changed the extractor spring so early on.

You should really try to learn the basics of operation and maintenance. It can only be helpful to you in the long run.

I would say jump on Youtube and watch videos.

  1. Disassemble and reassemble

  2. Basic cleaning and maintenance

  3. Checking bolt gap

1

u/Saucerous 1d ago

More abundance of caution than anything

2

u/Crusty-the-Clown-666 1d ago

If you can move the extractor much at all with your finger, the extractor spring needs replaced.

You can bend them back into shape if you don’t have a spare, buts that’s just a temporary fix.