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

[pug]

Brian one of the main things with subsonics is you want to get away from the possibility of having a secondary detonation which becomes more of a possiblity (so said) when using less than a 50% case charge. Also it is said the burn inside the case is not consistant when using a low charge leading to inaccuracy. With 6mm bullets you will probably be under 10gr of powder and that is a definite under charge in a 223 case. That is also one of the reasons for using 221 brass in addition to bullets length, the 221 is the right case capacity for subsonics. It should not be a problem to push the shoulder back on a 223, trim it and then expand to 6mm and seat a bullet. You can either make a dummy round up and have a reamer ground to its specs or find someone who has already done it. Have fun.

After posting I did some checking on reamers and dies and you may want to get info on the 6mm Mach IV. It is a 6mm based on the 221 case and both reamers and dies are available from standard sources.

[demonslayer]

anyone know a sutible twist for the 6mm wisper?? brian