Battle Bracket Round 2 set: Vote for your favorites

US soldiers (R bottom) hold position after exiting a US Army UH-60 Black Hawk helicopter during a combined arms live-fire drill at the Rodriquez Multi-Purpose Range Complex in Pocheon, north of Seoul, on March 25, 2015. The drill is part of the annual joint exercise Foal Eagle to enhance the combat readiness of the US and South Korea supporting forces in defense of the Korean Peninsula. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images)

An upset here and a buzzer-beater there, and your chances at winning the office pool are gone — especially if you’re in the Navy, in which case there was never an office pool and never has been.

But don’t give up hope: We’ve got you covered with Battle Bracket, where Round 2 voting for the best piece of military hardware will march on through the first weekend of college-hoops play. Check out some of the second-round showdowns below, and click here to cast your ballot on all the matchups.

Main event: Only two helicopters remain. Will the AH-64 Apache stand tall, or can the UH-60 Black Hawk move on? Get your fill of specs on this rotary showdown here and here.

Sleepers: The F/A-18 Hornet series will square off with the F-22 Raptor for aerial supremacy and some servicewide bragging rights. And the B-52 Stratofortress will hold a bit of a size advantage as it battles the MQ-9 Reaper.

Nimitz-class carrier vs. America-class amphib in Round 2, with the winner in position to run the table in the Sea region.

Photo Credit: Defense Department images

Sea region

Main event: It’s a flattop faceoff, as the Nimitz-class aircraft carrier takes on the America-class amphibious assault ship. Marines could cast the swing votes; their favorites have a strong track record in such contests.

Sleepers: The USS Constitution survived a strong challenge from the Freedom-class littoral combat ship to reach the second round, where it will face the Ohio-class submarine. Key stat: The depth charge was first used during World War I, more than a century after the Constitution’s commissioning. … The Aegis combat system will battle the Close-In Weapons System after fending off a late charge from an early favorite — shipboard coffee — in the first round.

Personal region

Main event: Basketball fans often discuss the “style clash” that can result from NCAA tournament matchups, but will anything come close to a poncho liner facing off with a shoulder-mounted AT4 rocket launcher? Not likely. Don’t underestimate the “Woobie,” which rolled past a bottle of Motrin in a lopsided first-round win.

Sleepers: Take aim as the M4 carbine battles the M1911 pistol, with the winner possibly facing the Ka-Bar knife in the third round. … The PT belt proved no match for the Marine “knife hand” in Round 1, but the sometimes-criticized, frequently memed gesture will face a bit more firepower this time, taking on the Mk 19 grenade machine gun.

Photo Credit: Courtesy photo Soldiers use the M777 howitzer to fire high explosive munitions in support of Operation Enduring Freedom in 2008.

M777 howitzer vs. Bradley Fighting Vehicle — the winner could see an Abrams tank in the next round.

Photo Credit: Defense Department images

Land region

Main event: The M777 howitzer takes on the Bradley Fighting Vehicle, with the winner possibly staring down the region’s presumptive favorite, the Abrams tank, in the next round. The Abrams pounded the Sherman tank in one of the most lopsided first-round bouts and will face the M270 Multiple Launch Rocket System in Round 2.

Sleepers: Not a fan of tracks? Tires more your thing? The Cougar MRAP will face the Humvee and the Stryker will square off with the M120 mortar system, which edged out the M119 howitzer in the first round.