I have the .308 and the the barrel measures 1-1/8" diameter in front of the nut and uses the large Savage wrench, but the barrel has a shoulder and the threaded diameter is 1-1/16" and 20 TPI, which fits the Savage SA small ring receiver. The head space on the barrel was 0.134", which was 0.007" clearance on the Marlin bolt nose and 0.022" clearance on the Savage bolt nose and required using the Marlin barrel nut. Savage recommends 0.130" or less head space. The Marlin X7VH would benefit from a heavier after-market Varmint/Tactical prone stock. The EGW Winchester 70 SA 20 MOA rail fits the Marlin X7VH action, but I had to shim the rear end 0.010". - nhk