One of the last American combat units stationed in Europe is asking the government for bigger guns amid rising tensions over Russia’s involvement in the Ukraine conflict. The 2nd Cavalry Regiment is requesting that 81 of its 8-wheel-drive Stryker infantry carrier vehicles be equipped with 30-mm. automatic cannons -- double the caliber of the 12.7-mm. guns they already carry, the military news website Breaking Defense reports. The House Armed Services committee is already setting aside money for the upgrade, which the Army approved Wednesday, according to a memo obtained by the website.