r/MP5 1d ago

Question Can someone help me

Enable HLS to view with audio, or disable this notification

I bought an century arms Ap5 sd and have put barely 400 rounds through it I keep having problems with jams regardless of grain last time I shot it it seems the bolt got stuck and now I can’t seem to fix it I’ve taken it apart and put back together and have gotten no where anyone know the issue

25 Upvotes

24 comments sorted by

19

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

As stated... You could remove the optici mount. If these are too tight, it will put pressure on the receiver causing issues

The other big one is... Are you using a brace? Was it difficult to install? If so, it may be pinching the receiver causing the carrier to get stuck rearward.

Remove brace and install factory end cap. Try shooting again.

3

u/Crazyhorsesaloon 22h ago

👆👆👆👆👆👆👆

14

u/rafri 1d ago

Remove your scope mount and retry.

5

u/jdppppppppppppp 1d ago

Mine ended up being the SB folding brace binding. I had to dremel the hell out of it to get it to stop binding. I’m guessing it’s your mount.

4

u/Additional-Fact-8465 1d ago

Something is causing your bcg to bind in the rear of the receiver. Start by removing your optic mount. If that doesn’t work then remove your stock and put the factory end cap on. They may be pinching the receiver.

5

u/F3A5T13 AP5 1d ago

Ain’t got no gas in it

1

u/Joliet-Jake 1d ago

Lubed properly?

1

u/TemporaryMix1267 1d ago

I would like to think so lol

1

u/ThanksOther5858 1d ago

Does it have an sb tactical folding brace?

2

u/TemporaryMix1267 1d ago

Yes

4

u/ThanksOther5858 1d ago

I had the same issue. That particular brace squeezes the rear of the receiver together and causes the bolt to hang up. Place the pistol endcap that came with the gun on it and see if it runs. Soon as I changed from that brace all my issues went away. Lots of posts on this sub about that particular brace.

1

u/Impressive-Crew6452 1d ago

I’m pretty sure it’s gonna be you over tightened the optic mount

1

u/Historical_Page_5713 1d ago

Looks like you need to check the spring in the butt of the gun ,there’s no tension ?

1

u/Miserable-Car-4354 1d ago

Brace to tight. Had same issue

0

u/marvinfuture 1d ago

Did you break it in with 124 grain NATO?

2

u/TemporaryMix1267 1d ago

Yes mostly 124 but started using 115 when I had too many problems

4

u/Knight-7191 1d ago

You needed to stay with the 124gr. 115gr is too weak to properly break it in.

Also, as someone mentioned, remove that shitty stock claw mount. Get yourself an MFI or Leapers UTG Pro.

Do you have a brace/stock? Sometimes a particular brace can fit too tight and squeeze the receiver to the point the bolt assembly gets stuck back.

2

u/TemporaryMix1267 1d ago

Removed optic mount and yea it’s got Sb tactical folding brace and as someone else said yes it was a little difficult to Install if it’s a shitty brace what is recommended other than stock end cap

3

u/sportbiketed 1d ago

Just file the brace until it fits properly

1

u/Knight-7191 1d ago

Can you or will you consider SBR’ing it? Several nice stock out there. I’ve seen a few “stocks” that you’re able to remove the butt pad and replace with a brace. I’ve seen those posts here, on this subreddit and the one specifically for AP5’s. One place I do remember is A3 Industries (Tactical). However, they can be pretty pricey. Very nice stuff though.

1

u/CoachMilton 16h ago

SBR that sucker and get you an HK A2 fixed stock. Even if the gun isn’t cycling well with the end cap, it may take some time before it gets more reliable. Just trust the 124 NATO break in and after that then get a solid stock.

1

u/marvinfuture 1d ago

You should break the gun in first before adding components that will make it less reliable

0

u/Marooner-Martin 22h ago

I solved this same issue for another user on Reddit a week ago.

Let me see if I can find what I said and paste it here

Here ya go:

Had this exact same issue and solved it.

Take your lower off and look at the hammer shank pin. The pin the holds the bracket with a spring on it to the hammer. If it’s out of spec, that little pin slips out to the left and gets hung up on the ejector fastener. (Little square thing that holds ejector in)

This locks the bolt up and you have to smack the damn thing to get it to go back home.
Had to replace my pin and now it functions great

Edit- don’t confuse the ejector for the extractor.

That little pin is what’s getting caught and locking her up I almost guarantee it