New to the Bushmaster Thumper 450

[TheHive]

Hi Fellow ODTers
I just found a 450 upper and I find the need to add a rail, but the nut used on these is strange to me and looks like it
would not fit a troy or any rail i find, has anybody got any experience with these that can point me in the right direction?
its a stock bushmaster 450 upper, I also could get by with a gas block mount rail as the real need is for a laser/light combo.
its 16" carbine.
Thanks for looking!

 

[Eglock86]

I had a .450BM that had a DD rail on it but I got it that way. They are badass rifles. You will love it. Dosn't take long to realize why they call it a thumper.

 

[opps]

Those are the older design tube hand guards. Also used by DPMS.
You need a light torch to heat the rail to unscrew it off the nut using a strap wrench. Then use the proper barrel nut wrench to remove the barrel nut.
You should be able to use any rail - would suggest calling Bushmaster to confirm but if a DD fits - most fit.
Not sure I'd the barrel is .920 or not. Any low profile gas block should work that has the proper diameter.