Nothing special fitting the bolt head, it swapped right out. The barrel on this one came off pretty easy, make sure it's gripped tight, use heat and strike the wrench with sharp blows. I've done all three of my older a-bolts and two of my buddies, I have had to make relief cuts on a couple of them to get them off..... seems like the 32TPI tennons stick more to me while the 20TPI break free easier..... I've heard the horror stories about ruining actions myself but all 5 of the ones I've done came out without damaging the actions.
Get a good external action wrench, I use the wheeler with browning heads.