Differential Cover Test - The Great Diff Cover Shootout

Cover: Extreme Metal Products
Construction: Formed, welded, and powdercoated 1/4-inch steel
Notes: The .357 produced some very slight warping and a hint of a dent. The .454 passed cleanly through, leaving nice holes.
Caliber rated: .454 Casull
Contact: Extreme Metal Products; 800/262-2768, www.extrememetalproducts.com

Cover: Riddler Manufacturing
Construction: Thick, ductile cast iron with raw finish
Notes: The .454 dented and cracked the inside of the cover, but didn't produce a hole that would weep oil. The .460 easily blew holes cleanly through.
Caliber rated: .460 S&W
Contact: Riddler Manufacturing; 303/651-7757, www.riddlermfg.com

Cover: Blue Torch Fab
Construction: Formed and welded, high-strength, 1/4-inch steel plate with raw finish
Notes: The .454 was able to dent the cover with no penetration. The .460 dented the cover and cratered the steel, but failed to penetrate. The 7.62 punched a clean hole straight through.
Caliber rated: 7.62 Soviet
Contact: Blue Torch Fab; 334/673-2755, www.bluetorchfab.com

Cover: Gear Tech Heavy Duty
Construction: Extraordinarily thick nodular cast iron with painted finish
Notes: Just heavy to lift. The .460 produced some cratering of the steel and slight cracking on the inside, but nothing that would cause a leak. The 7.62 cratered and dented the steel to a larger degree, but again caused nothing that would prevent the cover from functioning. The .303 easily passed through, punching a small hole on the outside and fracturing and shattering the inside with a conical wound channel.
Caliber rated: .303 British
Contact: Gear Tech Heavy Duty; 601/898-4552, www.geartechhd.com

Cover: Great Lake Extreme Offroad
Construction: Formed and welded, high-strength, 1/4-inch plate steel, 1/2-inch thick steel ring with raw finish
Notes: The .460 produced a dent and cratered the steel to a degree, but didn't penetrate. The 7.62 punched a clean hole.
Caliber rated: 7.62 Soviet
Contact: Great Lake Extreme Offroad; 260/387-1428, www.greatlakeoffroad.com

Cover: OX Offroad Products
Construction: Cast, high-strength steel with powdercoated finish.
Notes: Driver-side (from about "X" and over) is over 1-inch thick. Extraordinarily rugged cover. The .460 cratered the steel and put a slight dent inside. The 7.62 produced a similar dent with slightly more cratering. The .303 passed straight through the "O" for a bullseye. A similar impact of .303 in center of "X" produced only mushrooming crater of the steel.
Caliber rated: .303 British
Contact: OX Offroad Products; 877/694-7699, www.ox-usa.com

Cover: Great Lake Extreme Offroad (up-armored version)
Construction: Same formed and welded, high-strength, 1/4-inch plate steel, 1/2-inch thick steel ring with raw finish as other cover but with a 1/2-inch armor strap down center of diff. It's a legit option on the company's Web site, so we tested only the 3/4-inch thick up-armored part
Notes: The .454 Casull glanced off the side of the armor and cracked the weld where the cover meets the mounting ring. Regardless, we hit it with .460, 7.62, .303, .450, and finally 22-250. The only difference was the depth and size of the crater in the mushroomed steel. We did manage to create a big dent on the inside of the cover with the .450 and the 22-250, but it's nothing that would put the cover out of operation.
Caliber rated: Bulletproof
Contact: Great Lake Extreme Offroad; 260/387-1428, www.greatlakeoffroad.com