I am wanting to put another barrel on a dpms panther oracle . Is this difficult ? Can I do it myself ? 18 to 20 inch with 1 to 7 twist . Any recommendations ?
Not too hard. But invest in a good shop vise and an upper receiver vise block. And get some red locktite for your gas block screws. If they're already loctited on by the factory, you might need a propane torch to heat the block and take them off.
Review the cost of needed parts and tools to perform the swap and see if it is worth it to you.
Palmetto State Armory has 18" and 20" 1:7" twist barreled uppers for $219.99 shipped to your door.
a gunsmith once told me the AR15 is very forgiving to incorrect procedure.
that said, if you want to do it the right way and not risk damaging your upper receiver, get a Geissele Reaction Rod. A vice block will work, but you could warp the receiver or damage the pin index slot when torquing the new barrel.
Also, if using gas block with set screws, use Rocksett instead of red locktite. Rocksett is a ceramic threadlocker with a much higher heat resistance than red and a torque resistance similar to blue. That way if you ever have to remove it, you can.
If you only plan to do this once, just buy another upper already assembled as others have said.