The last sniper rifle I fired was the
M21 Sniper Weapon System. Special Forces made design changes to it (after my time there) and it became the
M25 Sniper Weapon System for use by SF and SEALs. The M24 Sniper Weapon System replaced the M21 for the conventional military.
Have you been using any alpha-numeric combinations that can be associated with sniper systems; or, terms that can be associated with snipers in your searches for other things?