Can someone help me out? The "locking lug" on the buffer tube is different than the ones on my Bushy and Colt. Damn thing doesn't want to budge. Any help would be greatly appreciated.

Thanks,
John

You mean the castle nut?  Do you have the right wrench for it?

I wasn't sure what that part was called, but I'm sure we're talking about the same thing. The nut on my other two AR's have the notches at the end of the nut, but the KAC one only has a small hole in the center of the nut located at the 9 o'clock position. The wrench I tried was basically a handle with a "C" hook at the end. I've used it several times on my other ARs, but this time no budge...

Thanks for the reply,
John

F' it, get out the channel locks.

Hell, I tried the vice grips and beat on it with a hammer with no freakin luick.

A little heat on the nut might help in anycase.  The wrench I use is just a head that attaches to a standard square drive.  It has one replaceable tooth which is round stock and fits the KAC hole perfectly.  It's taken off more than one Colt staked nut with ease and no assistance other than a bit more pressure.

In anycase, the nuts are cheap - just use some channel locks and some heat if need be, then replace it.

ETA: pic of the tool I use.  Cool things are that it easy to use with a torque wrench if that's your bag, and the tooth is not only easily replaceable, it can be custom ground/profiled as it's just a pin held in with a set screw.

Here is a link showing two types of castle nut wrenches.

www.rockriverarms.com/item-detail.cfm?ID=AR0150&storeid=1&image=tools.gif&CFID=4207994&CFTOKEN=44661674&jsessionid=0630697a0e96$ED$BF$D

Heat was the trick. Thanks for all the help.

John