The M24 is still the standard U. S. Army sniper rifle as far as I know.
There is a lot of info available on it on the web.
The U. S. Marine Corp uses the M40A3 now I believe. The M40A1 is now or has been replaced.
SpecOps types use other "standard" sniper rifles.
Sniper Rifles of the World internet search.
Sniper rifles are not IMHO specifically designed for extreme accuracy, they're designed for a marraige of accuracy, durabilty and maintenance ease. A long range bechrest rifle should certainly be more accurate but you probably wouldn't want to literally drag it across the ground, over rocks and through streams and then rely upon it to make a one shot hit at long range... this is where sniper rifles excel, they're durable.