Hi this is the Published data by ADI that devolped Retumbo especialy for the 300 RUM i shoot with one of the balastitions that works at ADI the data is as follows.
ADI AR2225 (Retumbo)
300 Remington Ultra Mag
Start, Vel, Pres, Max, Vel, Pres
190gr
90.0gr 3069fps, 56500psi, 96.0gr, 3204fps, 62500psi
200gr
81.0gr 2852fps, 56200psi, 86.0gr, 2988fps, 62800psi
220gr
84.0gr 2800fps, 56600psi, 89.0gr, 2905fps, 61900fps.
all data in a 24" test barrel
Hope it helps
Cheers Bill
Australia