Sample Modern released a nice pack of free marching snares samples for Classical, Orchestral, Ambient, Rock/Ballad and other music genres.
Free Marching Snares Samples
From Sample Modern:
Marching Snares pack is designed and created to fit the needs of any music producer and composer, who is searching high-quality snare drum samples for free. The pack comes in 2 formats: WAV and AIFF (Apple Loops). 35 snare drum loops, both solo and ensamble loops are available. The tempo is various, from 110 up to 180 bpm.
You can hear the pack in action in this video: