Legacy Manufacturing, not to be confused with Legacy Woodworking, claims their MEGABOOST grease gun is the most powerful pistol-style grease gun out there. If you set the gun for boost, it’s able to deliver 10,000 PSI — or, if you set if for volume, it’ll pump out more grease per stroke than other similar grease guns.
Their claims may be something to shout about, but pushing grease into a fitting at 10,000 PSI probably isn’t a good idea unless you really know what you’re doing. If you need that kind of pressure to get grease into a joint, it could be clogged, and forcing grease into it might make things worse.
The gun’s dual-piston design allows the choice between high volume or pressure. Other benefits and features include extreme cold-weather performance, ergonomic MegaGrip handle, a bleeder valve for purging air, and a flex extension. Legacy makes the housing from cast aluminum, and the gun is fully repairable with a modular repair kit.
Expect to pay somewhere between $75 and $100 for the MEGABOOST.