Thread: Re-barrel decision - need a nudge

Wanting to re-barrel the Model 7 .223.

Have come down to a few ideas but before dumping a bit of coin I am after some opinions. Prefer not to have to faff with replacing bottom metal/ having detachable mags or modifying bolt face. FWIW it's my 0 - 200m-ish bush rig.
So far I am thinking either:

1. Faster twist .223.
Already have dies, brass etc, but may be hamstrung by mag length somewhat.

2. 300blk.
Retain bolt size, gain a bit of diameter and choice in projectiles.
Easy to find dies, lee trimmer etc.

3. 6x45 (6mm .223)
I guess kind of best of both, but hard to find dies it seems.
Can share projectiles with the.243.

Thoughts?