6mm whisper, or 6mm vertarg

[demonslayer]

i am wanting to build a whisper cartridge in this caliber, but i can t seem to find any info on either of these rounds. also, wanted to know if the 6x45 or (otherwise known as the 6mm/223) can be loaded with longer 105 grn bergers and a powder charge that would allow to be thromn at sub-sonic velocities.

i have a 6ppc barrel that i am going to use to do this change. i just need some info on the cartridges.

i like the whisper using to .221 fireball case because it alittle shorter. thus.. would fit better into the AR-15.

but, the 6x45, if possible.. can have a longer bullet pushed farther into the case because of the fact that i would be using a smaller charge anyways. onlt problem is making sure there is enough bearing space on the bullet so that it dosent slipp right inside the case. thanks guys, brian