I'm a newbie building my first upper. I read somewhere that it's best to have dedicated bolt carrier assemblies for different uppers.  For right now I'd like to avoid buying a new bolt carrier assembly to save some cash. Is it ok to use my old b/c assembly in the new upper? I don't plan on burning thousands of rounds through this upper (building a varmint rig with a SS HBAR barrel and FF tube). Also, does anyone know the cheapest place to get an armorers wrench and upper receiver vise block? Thanks, Whipper

As a general rule you want to use new to new then/or new to used.  If you need to use used to used then you need to check the head space.

It is recommended that you keep bolts with their respective barrels. You could save a little money by having a separate bolt for each barrel, but only ONE bolt carrier that is swapped around.

As for action blocks and armorer's wrenches, you might as well use what many consider to be the best:

www.bushmaster.com
Bushmaster action clamp -- #OM-003

www.olyarms.com
Olympic Arms armorer's wrench -- #H28B

i keep the bolts with the bbls they came with.


but its your money so do as you please

I agree with keeping the bolts with the barrels. As for the carriers, I dont think that would have any effects at all.

I was kind of wondering this as well.  I have a complete factory bushmaster that I am changing out the barrel on for another factory bushmaster barrel.  Just a different twist rate.  The origional complete rifle probably has about 400 rounds through it.

Do you think it is safe to keep the origional bolt with the new barrel?  I wasn't planning on getting a new bolt.  Trying to save some cash in this project.  Would only 400 rounds wear a bolt that much that I would need to get a new one to match the new barrel?