I need one to accomplish a little home brewed AR repair (loose barrel). I've looked at both the Bushmaster offering, and the 'Delrin' block sold by Brownell's. Aside from the lack of an action insert on the Bushy model (or at least they don't show one on the website), is one any better than the other? The Brownell's unit is about 6 or 7 bucks more than the Bushmaster.

I would have preferred to have a qualified gunsmith do the work, so I asked a local gun shop owner for some help (he was recommended by an aquaintance as having extensive armorer experience in the Marine Corps). He made kind of a goofy statement after I explained my problem. "...if it's not a Colt, I can't touch it....it's a liability issue...If I did any work on it, it'd be considered manufacturing a Class 3 machine gun..."

I'm still scratchin' my head over that one.

both blocks will do the trick.  id go with the cheaper one myself.  if you need any help or have any questions on your repair u can reach me on aol at millerharley76  or u can email me at [email protected]

I use the old style block that completely wraps around the receiver, and has an insert that goes into the action to the block from crushing the receiver.  The only downfall to the old style is that it can leave pressure marks on the receiver. To solve this, I spray rubberized tool grip spray on the inside of the block to cushion the block against the upper receiver.

P.S. The only time it marks the upper (untreated) is when I turn the unit over (vised wrong) to index a DCM tube (sling) to the centerline of the receiver.  My guess is that the new style block has resolved this problem, and is the reason that is being currently sold.

I have one of the new style blocks from bushmaster and it works great.  It may be possible to crush the receiver with it, but you would have to be a complete idiot and way over-torque the vice handle to do it.

If you get the vice pretty tight you will notice that removing or installing the barrel in the receiver will become a little difficult since it does pinch the reciever some.  If you are really worried about over tightening the vice block, you could just leave the bolt carrier and charging handle in the receiver when you tighten it down to prevent you from over-doing it.