This unit is compatible with common .308 Win loads as well as some .223 Rem hunting loads.
That depends on your needs and preferences. Please email us at techsales@opticsplanet.com and we can provide some recommendations.
The rifle scope is fog resistant because to be "fog proof" would mean that the rifle scope will not fog on any of the lenses and that is near impossible. Fog will not build on the inside of the optic because it is waterproof and nitrogen purged, but fog in some instances will collect on the outside of the lens. The only way to avoid that would be to apply some sort of coating that may degrade the optical clarity. The glass and rifle scope are manufactured in Japan, but we do not have information on the specific company manufacturing them.
The Primary Arms 6-30 x 56 mm Rifle Scope would be a great option for your Savage Rifle. Because you already have a picatinny top rail, I would recommend using the 1.44" NightForce UltraLight Unimount Rifle Scope Mount, found by using the link below:
https://www.opticsplanet.com/nightforce-uni-mount-one-piece-20moa-mounts.html?_iv_tube-diameter=34-mm&_iv_code=NF-MT-UNIMOUNT-A257
The Primary Arms 6-30 x 56 mm Rifle Scope will work well mounted to a rifle chambered in 6.5 Creedmoor. The rings you will need to mount it will depend on the rifle and scope bases you are using. The guide at the link below will help you determine what rings you will need.
https://www.opticsplanet.com/howto/how-to-how-to-measure-scope-height-scope-ring-height.html
To mount the Primary Arms 6-30 x 56 mm Rifle Scope on a Ruger Precision Rifle I recommend using a cantilever mount like the one listed below.
https://www.opticsplanet.com/scalarworks-qd-scope-mount.html
The ammunition used: 6.5 Creedmoor - Hornady: (140 grain / ELD), (143 grain / Precision Hunter ELD-X), & (120 grain / AMAX) | .224 Valkrie - Federal: (90 grain / SMK) & Hornady: (88 grain / ELD Match). For more detailed ballistic specifications please review the scopes manual.
If your general shooting range is 600 yrds and occasionally may extend out to 1000 yrds, I'd recommend going with a 20 MOA mount.
Please email us at techsales@opticsplanet.com so we can further answer your question.
This scope would be great for your Ruger Precision Rifle. For the Ruger Precision Rifle a short offset single piece mount similar to AR cantilever mounts are very popular or a set of extra high rings would also work.