I shoot the RMR 69 bthp mostly out of 18\” 1:8 upper, 24.24 grains imr 4046 at col of 2.255.
I also have a heavy barrel bolt gun I use with a couple higher priced bullets . I decided to load up some rmr 69s, 23.5 grains imr 4064 with a little longer col of 2.315 to use as fowlers and they shot amazingly well, my 1st 3 shots had a spread of .292\”, the 4th was off so stretched that group to .568…thats pretty decent for a bullet which cost 15 cents