The Red team uses Glocks. It's common knowledge that NCIS standard issue side arm is the SIG-Sauer which is the case for the regular cast members of NCIS: Los Angeles (with the exception of Deeks who is still an LAPD officer and has used a Beretta 92F which is the standard issue side arm for LAPD) and in the original NCIS.
In the segment with the starting transport air plane at the beginning, the sound is clearly that of a landing plane.