If your RAW is capable of shooting 1/4 groups at 50 yards then in the same conditions with the same shooter it should continue to shoot 1/4 groups.
what you need to do is explore the reason why something’s the groups open out, any loose components on the gun, any inconsistencies over the chrono, faulty magazine, dirty barrel, pellet selection, bottle securely fitted to the gun etc. Once you have ruled out everything gun/pellet related, start to look at the shooter.
when you are aiming for perfection then the smallest thing can make a difference, keep a log of when the gun is shooting well and not so well, temperature and atmospheric pressure can affect the flight of the pellet, cold air is more dense so pellets move more slowly through it, low pressure and high humidity have the same effect. Warm , dry air high pressure have the pellet moving faster. Temperature also changes the way the internals of the gun react with each other, cold will make oils more viscous, components shrink in size alternating the fit be
tween part. A difference in the speed of the pellet by only a few fps can have a noticeable difference in accuracy.
What speed are you shooting at? Often guns are pushing pellets too fast, yes a fast pellet gets there quicker and has less of a trajectory arch to contend with but I find that in the smaller calibres, .177 - .22 then speeds of 780 -850 fps seem to be the optimal for precision.
My advice, stick with what you have and stick at it.
Bb
PS
This target was shot at 45 yards, outdoors moderate tail wind. Theoben rapid .177 AA Diablo fields at 780fps
the top group (on the 6) is 8 shots single loaded
the middle group is 17 shots magazine loaded, notice the slight change of poi with the mag or it could be a slight lull in wind speed?
the pellet below the target is a .177 pellet that I pushed into the hole of a 4 shot group single loaded.