Greetings!  First time posting here, I bought a Daniel Defense DDM4 PDW which is chambered in 300 blackout pistol.  I have a limited supply of rounds to play around with, but its so unbelievably expensive I don't even want to shoot it until I can replace it for a decent price.

I'm looking for some input regarding whether I should do a barrel swap, or if I should put together a dedicated upper to provide some options since 223/556 is more available.

Option 1. ) buy a barrel and just stick it out with that caliber until ammo loosens up and I can rip the 300 blackout (without getting another job)
Option 2.) put together a new upper for a quick change out

Questions I have:

Does the buffer tube need to be swapped if I go from 300 blackout to 223/556?  I know the spring most likely does because it ships with a spring meant to be used with suppressed rounds.  

What else would I need to do if I'm ready to "pull the trigger" on running 223/556 out of this new piece?

Thanks in advance for your help.

Your question would be better answered in the Daniel Defense forum. Joe Marler is the DD rep there.

Danien Defense Forum

I have a PDW.

Option 2.

You will most likely have to change the tube and spring, but you can get away with using the same castle nut.

Thanks, Appreciate it!