Can't swear to it, since all my bolts are Colt GI surplus, but if I recall correctly, the Bushie bolts I've seen coming out these days are not marked any more. I suspect that they ran out of the GI spec bolts left over from the M4 contract, and just went into the subcontractor market like everyone else.
Understand, the ONLY reason Bushmaster ever got that M4 contract was because of the owner's connections with the Bush family, or don't you remember where the Bush's summer home is?[:D] Except for the standard hard chrome lining on their barrels, and using GI spec steel for the barrels, their products are no better than any of the other top aftermarket producers. The Rock River lower I bought last Saturday makes my Bushmaster lower look sick by comparison, and I paid $50 LESS for it.
If you do, in fact, need a new bolt and/or carrier Bushie is a good aftermarket brand, but so is Rock River, DPMS, Armalite, and several others. If you're not going to use Colt innards, all the top aftermarket brands are about the same, and you should start shopping price.