"someone tried telling me that they were just standard Remington 700's marked M24."
That person does not know of what they speak. The M24Rs (M24 Rebuilds) reportedly utilized all US Army take-off parts except for the following 3 items that are new:
1. New M24 contract barrel (after all, who wants a used barrel with unknown wear...BTW, these are M24 military barrels marked "7.62 NATO" - not "308W".)
2. New receiver correctly marked M24 (de-commissioned US military receivers are destroyed, and not re-sold to the public - except special programs via the CMP org).
3. New M24 trigger assembly (presumably too much liability to sell a "used" trigger assembly that might have been inappropriately modified by a service member)
The U.S. Army gave Remington permission to re-sell 2000 return stocks and all related M24 take-off parts that were serviceable for these M24R rifles. They are as close as one can get to an issued M24. I bought one of the rifles only in 2015 (already had take-off M3A Ultra scope and Leupold Ultra rings), and other than the serial # which is a RR prefix - its a true clone of the M24s in service circa 1988 to about 2010.