VFC receiver bonding material
 

Does anyone know what type of glue, adhesive or cement VFC use to fasten the fake bolt assembly to the upper receiver of their M16/M4 type weapons? This would be laminating injected molded plastic to a metal surface. Hard to understand why an otherwise quality design would resort to gluing these parts together. Whatever they use doesn’t seem to hold up to well. I’ve run into several that are either almost falling off or close to it.

Can you post a picture? My 416 has a plasticy coating on the fake bolt that appears to be like a heat shrink type of material.

Have you tried contacting VFC? I've talked to them by email in the past, and they've sent parts out that were not available at places like WGC, Redwolf, Etc.

Danke,

you can see the fake bolt in M4ES_DRAWING.pdf under part number M4ESF-3

From the line drawing it seems exactly the same as the 416 one but since that's their economy line it's hard to say if they process them the same way.

Can you shoot a picture of the actual seperated part?

I have seen some parts from Taiwan where the bonding just let go, I don't know if the rushed the process or if they were out in the back of the factory doing the bonding on a day it was 98% humidity

I see you tweaked your original post. On what I have seen the fake bolt is connected to the charging handle and moves back so you can adjust the hopup dial.

On the E models it's just stuck inside the ejection port?

I haven't any picutes handy but I don't see how a picture could help in this case. The part that the spring connects to is glued to the upper receiver. The spring causes the fake bolt to slam forward when the bolt release is pressed. The fake bolt is comprised of three parts (a plastic part, a spring and the fake bolt itself). The plastic parts seems to not be glued very well to the recievers. If you have to change the upper receiver for any reason you have to remove the plastic part and reglue it to the upper receiver, I would just like some input on what type of glue or adhesive is to be used for this type of work? The pressure of the spring pulling forward on the fake bolt actually helps pull the pastic part away from the upper receiver adding to the failure rate that I'm trying to describe here.

If I was fixing something like that I'd think about tapping and putting in a grub screw to hold the spring. If there's' not enough meat to do that I'd use a 2 part epoxy.