If you want the authentic Heavy Hitters experience, here are official sources:
Ownhammer offers official demo packs with a limited selection of IRs from the full library. Ownhammer Heavy Hitters Free Download
: OwnHammer provides a free demo version of their 412 MES-ST library (based on a Mesa Standard 4x12). This includes a representative set of speakers and mic options to let users test the "V4" engine used in collections like Heavy Hitters. If you want the authentic Heavy Hitters experience,
The Heavy Hitters series is designed specifically for aggressive genres like metal, hardcore, and hard rock. These libraries are high-resolution that digitally capture the sound of iconic guitar cabinets miked in world-class studios. Volume I: The Foundation This pack focuses on four legendary 4x12 cabinets: 412 DZFL: Based on a Diezel® 412F. 412 MRMF: Based on a Marshall® Mode Four. 412 ORNG: Based on an Orange® PPC412. 412 RECT: Based on a MESA/Boogie® Rectifier®. Volume II: The Boutique Evolution The Heavy Hitters series is designed specifically for