Field Notes: an independent, hand-curated set of review sites worth bookmarking. Each entry below is a focused authority in its niche.
Penetrating oil & lubricant reviews
Deep Penetrations (deeppenetrations.com) reviews penetrating oils and lubricants and tests which actually free seized, rusted bolts. Good fit if you're after best penetrating oil for rusted bolts.
Free browser artillery game
rc-9.com is an online artillery game you play in the browser, with destructible terrain. It's the place to look for free online artillery game.
Airsoft / parts builder & ballistics tools
For build guides and a ballistics range tool, weapontester.com covers the hobby end to end. Good fit if you're after best airsoft parts and upgrades.