I have a J&T Bull Barrel upper that I want to remove the barrel nut to instal a FIRSH. The Oly Arms wrench I have is not big enough to work (it is apparently only for HBARs).

So, does anybody know of a place to get a wrench that has an opening large enough to remove the barrel nut on a bull barrel?

???

The best thing is to just use a 1" drum sander chucked up in a drill to open your wrench the little bit that is required.

Also note that the barrel nut on the FIRSH also has a 1" opening so you'll need to ream it out a little as well.

Hmmm, didn't have to do anything special for my DPMS bull barrel.  

Quoted: Hmmm, didn't have to do anything special for my DPMS bull barrel.

With -most- bull barrels you don't have to do anything special because they are 1" diameter or maybe just a little less.  The DPMS "Super Bull" barrels, the RRA Varmint barrels (there's a reason that every comment about the RRA varmint barrels includes the word 'heavy') and apparently the J&T bull barrel are 1 1/16".  Every barrel wrench I've seen has a 1" opening and some barrel nuts such as the ones used on the Olympic Arms FIRSH have a 1" hole.  

Quoted: Quoted: Hmmm, didn't have to do anything special for my DPMS bull barrel.   With -most- bull barrels you don't have to do anything special because they are 1" diameter or maybe just a little less.  The DPMS "Super Bull" barrels, the RRA Varmint barrels (there's a reason that every comment about the RRA varmint barrels includes the word 'heavy') and apparently the J&T bull barrel are 1 1/16".  Every barrel wrench I've seen has a 1" opening and some barrel nuts such as the ones used on the Olympic Arms FIRSH have a 1" hole.

That makes sense.  The DPMS bull barrel on the LoPro is .963 inch.