I can not get my KAC M5 rail on...period.

[Eurodriver]

This isn't my first rodeo, I've installed countless m5s, I even had our unit armorer help me out . (he seems to think the parts aren't milspec...and he wants to file everything) This is on a BCM upper.

It just won't go on. Its driving me nuts. The rear end with the screw won't slide underneath the delta ring no matter how much we mess with it. We've banged on it, twisted it, nothing.

What am I doing wrong?

[Iraqgunz]

Can we assume this is a true KAC rail? I only ask because there are Chicom knock offs out there. Being in Hawaii it is conceivable.

Other than that I would say that there could be an issue with the barrel nut. I would see if you can acquire on and swap it out.


This isn't my first rodeo, I've installed countless m5s, I even had our unit armorer help me out . (he seems to think the parts aren't milspec...and he wants to file everything) This is on a BCM upper.

It just won't go on. Its driving me nuts. The rear end with the screw won't slide underneath the delta ring no matter how much we mess with it. We've banged on it, twisted it, nothing.

What am I doing wrong?

[Eurodriver]

Yes, it is a legit KAC rail.

We got it. Only took 4 hours....I installed a KAC rail on my M4 and it took like 20 seconds. I have no idea why this was being such a PITA.

I wanted to get pics of my entire AR today but its already late and I got an early day. Here's the upper at least.

http://img26.imageshack.us/img26/2285/p8240031.jpg
http://img638.imageshack.us/img638/246/14322319.jpg

[Iraqgunz]

Did you figure out what the hang up was? Was it just because everything was new?


Yes, it is a legit KAC rail.

We got it. Only took 4 hours....I installed a KAC rail on my M4 and it took like 20 seconds. I have no idea why this was being such a PITA.

I wanted to get pics of my entire AR today but its already late and I got an early day. Here's the upper at least.

http://img26.imageshack.us/img26/2285/p8240031.jpg
http://img638.imageshack.us/img638/246/14322319.jpg

[Eurodriver]

I honestly couldn't tell you what it was. We just kept twisting and pulling and pushing and then it just snapped into place. :confused:

Maybe because that damn delta ring spring was so freaking tight

[Kilo 1-1]

I had the same issue with my KAC RAS (for carbine) when first installing. The delta ring spring was just too stiff....took me 2+ hours to get it in. Once the spring wore in, getting it on and off took only seconds.

[SHIVAN]

Long ago, when I was fitting an M5 to an AR-10, it took a long time due to the ring tension and angle of the interface piece that engages it.

Glad to see you got it!!!

[whiterabbit05]

Maybe a hand guard removal tool would have helped?

[TOrrock]

Sometimes you just gotta hold your mouth right.