I am having a HHS Blaser pistol made , what caliber would you choose. I was looking at a 7MM STW but the short Barrel might hurt it .

My pick would be the 308.

I have both the 7 WSM and the 7 SAUM in HSPrecision handguns ( bolt action single shots) the short magnums work very well with the 15" barrels.
nmhunter

I went with 300 wsm. I can always switch Barrels easily. Going to put a brake on it.
can make it right or left hand just by changing the Bolt.

NOW WHAT SCOPE??????????????