still apples to oranges 139 is lighter for a 7mm and a different design with the sst compare it to a similar bc in 7mm like the 162 eldx to let the true differences show between the caliber and if you remember the polymer on the sst will start melting at the distance where the eldx polymer will...
The 6.5 prc is more of a short action magnum than anything, similar to what others are stating better comparison is 6.5 prc vs 7mm wsm both are short action magnums or 7mm08 vs 6.5 creedmoor or why don’t you do a combo with a 7mm creedmoor alittle bit of a wildcat if you are into reloading and...