Stealth identifying guns, Project Krypton’s strength

“The two soldiers facing St. George tensed and he saw one of the gun barrels shift off to his left. “U.S. Army,” said Stealth. She was a few steps behind him. “Their weapons appear to be M240Bs with a modified ammunition case and larger heat shields.”
“Yeah,” said St. George. He cleared his throat. “I thought they looked different.”
“It is classified as an infantry medium machine gun,” she said. “It is unusual for an entire squad to be armed with it because of its weight. Each one weighs over thirty pounds with ammunition.”

Excerpt From Ex-Patriots, pg 165-166
Peter Clines
https://books.apple.com/us/book/ex-patriots/id585738393