Getting accuarcy out of Winchester Z (zimmer) ammo. 29gns 700 fps

[RDavies]

I would like to build up a rifle for accurate plinking with the very quiet rounds such as the Winchester Z. (will try other ammo if it is also super quiet). Do people get chambers specialy cut to suit these cases? Are there any barrel twist, goove, size combinations which people use to get these 29gn bullets working well at the lower velocities?
I cant use a silencer, so I will need a longer barrel to keep noise down.

 

[mitch_04]

A lot of people use Aguila SSS(SubSonicSniper) rounds. 60gn bullet powered with powder, but it's weight keeps it subsonic. They use a 1:9 twist barrel, but from what I've read it usually doesn't seem to need it, alot of decent shooters with factory barrels.

 

[maxpower]

I would love to try the Aguila ammo, but unfortunately, we cant get it in Australia. I have had a good run with winchester subsonics and will continue to use them, but was after something even quieter for some occaisions.