“3000 mph at sea level with a turbine engine”
Back in 1967 the original engine for Granit was designed for M4 speed,later with the use of KR-93 engine redused to M2,2.But all this speeds are in medium cruise altitude,in sea level with KR-93 the speed is M1,5.

Spot on that man. This looks a lot like a vague hotchpotch of facts muddled together for flashy journalistic copy. RATTLRS was originally being designed as a hypersonic areoballistic profile weapon intended to hit short-duration ground targets before they could move off i.e it was pure land attack and fixed target.

Now because it looks like a P700 there seems to be an assumption that it is one?

The LockMart article suggests no such thing it says:

As a component of the hypersonic “pillar,” RATTLRS has an initial goal of testing a flight demonstration vehicle at Mach 3, and plans call for a second flight demonstration that will reach speeds greater than Mach 4 — or more than 3,000 m.p.h. at sea level.

…which means that M4 IS about 3000mph at sea level NOT that the missile will DO 3000mph at sea level. Have to read closely guys!

It seems an interesting capability to have. Certainly a short transit precision land-attack missile with 600nm of range is going to be useful in certain conditions but I dont see it as replacing the SSN/Mk48 combination as the USN’s premier shipkillers in anyway!!!!