So it didn't take me long to find this in the forums
But what worries me was this post
Originally Posted by DonKorleone
I have a Madbull JP frontend installed on my ICS m4.
I had to buy a Madbull re-threading tool and have my gun doc re-thread the body to make the frontend fit properly.
There was also a bit of wobble after it was installed, that was fixed by adding a rubber washer from a stock TM piston head to make it more of a snug fit.
Works great and looks slick as hell now!
Though, this was a year ago.. Any ideas? Thanks in advance guys, really appreciate it.