HK MP7A1 Body Cracked
 

Gents, I've got a crack at the back of HK MP7A1. Having hard time finding HK body, so I was curious where can I get a replacement or what are the brands that are compatible with this model and/or require least modifications done?

GBB? Then that's likely a KWA. HK is a real steel brand, not an airsoft brand (stuff is just branded/marked with real markings by some companies)

You can jbweld it to prevent future cracks.

I've heard stories where if you call Kwausa they can ship it, but not responsible if seized. (Replacement body)

Can you post pics of the breakage? I'm testing some experimental repair methods and would love to see what it can do on a polymer body. Allegedly much stronger than JB weld. Since it's experimental it would be for free of course ;)

If it's the kwa version and the crack is near the pinhole - does it affect function or performance at all? I have the same issue

yep, this is exactly where the crack. Going through one pin hole at the back.
It cracked after I've been shooting this gun outside at a +30 temperature. Mags were pretty hot as well. I could even hear that shots were extremely loud, which probably kicked the bolt back too hard, or something along those lines. I'll post a picture later tonight.
It does effects the performance as the bolt got stuck occasionally when I tried to play it.

Yes, it's GBB. You are probably right about KWA, I just can't find the original box after moving to verify the manufacturer.

I can definitely work with that but it depends on how comfortable you are with repairs. I'm not saying you can't get a replacement body but in a last resort effort to keep the gun it can definitely be worked on.

I've got nothing against repairs, if you want to test out your technique. I'd still want to get a replacement body, since this is my favorite CQC gun and it takes a lot of beating due to crazy game style. LOL, I'd love to get a steel body if I could for it.

Well since the real one isn't made out of steel you may have quite the wait.

LOL, ya I know. This is just a naive wish list :)

So i've just finished trying to repair Sash's MP7. I'm 1/2 for repairs with weldon-16.

The thing snapped off like it was nothing after 2 magazines; doesn't seem like it is holding up well against the recoil vibrations. It seems that the bolt is pushing up extremely hard against the pin that holds on that corner.

I'm still experimenting weldon-16 which is methyl chloride; a solvent used to fuse acrylic sheets and polycarbonate. So far it's proven effective at fixing the hinge on a kriss vector stock but not so much on a high stress point like that of the mp7. There's someone else selling an mp7 right now that has the exact same break on the exact same point so i don't think it's a material defect so much as a design on KWA's part.

I'm going to keep trying but right now i believe that weldon-16 or weldon-3/4 might be better at fixing these cracks than JB-weld.

Sorry i couldn't fix it this time, Sash but i appreciate you giving me a shot.

My KWA MP7 cracked pretty much the exact same place. Super glue actually seems to be holding up pretty well. I don't game it anymore but it's holding up to the basement commando-ing for the most part.

Yes it held when we first put the bolt in along with the pins. But after 2 mags of fill auto it ended up cracking when we tried taking the pin out. I'm sure it's fixable with the right preparation band maybe I didn't so it properly the first time.

Lately I've just been experimenting a lot with different solvents and epoxies and adhesives because I think there has to be a better substitute for jb-weld when it comes to plastic on plastic welding.

I've seen the exact same break on at least 3 different threads on the forums so it must be a design defect.

if you are interested in having a completely custom steel body made, message me. I have a contact who would likely be willing to do it (but it would cost quite a pretty penny as it would be custom machined).

Check your recoil buffer (a rubber part inside your gun that softens the recoil impact of the bolt).
A friend of mine had the recoil buffer pad of his mp7 beaten up from use, then the pad get loose and falls out of the gun. He shot a few rounds without the buffer pad and cracked his receiver.
If your pad is lost or damage, it could cause the crack or worsen the crack.