I normally shoot a Vudoo in my competitions and have been placing well. It's out at Lapua for testing right now so for yesterday's NRL22 match I shot my friend's base class RPRR with a Vortex Diamondback Tactical 6-24... this is compared to my other rig which is a 360 in an Envy Pro and a ZCO 5-27.
I spent the previous day zeroing to get my dope, using my own Center-X lot that I use in my other rifles. The RPRR groups okay, .5" at 50, 1.5" at 100, 3.25" at 150, and 6" at 200. The group sizes for 50 and 100 will work for any of the NRL22 Option 1 distances perfectly fine. I think the biggest thing people leave out is that regardless of what rifle you're going to shoot, consistent ammo that matches your rifle is really important. So if you stay Tikka or CZ or B14R, you're going to need to find the ammo that you can count on and you know how it behaves in the rifle.
The RPRR performed perfectly fine. The trigger broke crisp enough that I didn't have any issues, this was a 2.5lb trigger, but it was predictable. I never had an issue pulling too early or having my shot off due to needing some sort of 8oz trigger. I noticed that since I knew the rifle would group a little bigger, I was paying a lot more attention to my fundamentals to limit the wobble zone and have a much better follow through to have the highest chances of success. With a Vudoo I can flick the trigger and get away with it, but with the RPRR I did pay more attention. With the Vudoo I was able to do the 10 shot KYL stage in 40s, with the RPRR I took a little more time to make sure I was super steady and did it in 67s. Other stages were all similar in that I just took a little more time and paid more attention to detail, but nothing near timing out. The extra attention to detail actually made me do better overall.
Comparing scopes... I was very surprised at how much I enjoyed shooting the DBT 6-24. Once setup for me correctly (eye relief, cheek height, etc.) I had no problems getting behind it. I actually got behind it easier than my Vudoo, I think because my Vudoo is sitting at 50moa rail, and the RPRR is 30moa, that little extra decline I probably need a little more adjustment on my Vudoo's setup to get it more in tune. I might also just drop my Vudoo back down to a 30moa. Out to 200y I had no problems finding steel, holding over. Never blamed any shots saying if only I had my ZCO, the DBT worked very well. Now the turrets suck, only 6mils a revolution is lame, no zero stop, etc... finicky parallax, etc.. but optics wise I could see the targets, and ran the match around 12-16x. There was some heavy fog that rolled in, and yes it got trickier, and the ZCO definitely made it easier to see some targets through the fog just because of the additional clarity of shot out gray targets on a gray background, but honestly I don't think the scope is the limiting factor either unless you're really counting 1-2 shots off the podium. Vortex's thick reticle is really nice, allowing you to use it down at 10x. So I'd highly recommend somewhere in the Strike Eagle kind of glass would be good enough for a long time.
So rifle / ammo combo I think any of these rifles are going to be good enough for 100y and in competitions. When you're talking about 200y+ yes there's going to be a lot more reliability in a very tuned match barrel. 6" group at 200 vs a 3" group at 200 gives me an additional .4 mils of wobble, but in general competitions are created to be able to be shot by a 6" 200y rifle.
The Tikka T1X is also a much more accurate rifle than the RPRR. The Tikka T1X matched with a good lot of Eley Match/ Eley Tenex has been some of my smallest 6x5's at 50 and 100y.
Anyhow what all this boils down to is just do a lot of practice. You can do majority of dry firing. Use good, reliable, consistent ammo in matches, and don't keep swapping ammo. You should be confident that you know the exact dope of your ammo at distance. For the RPRR, I created a new profile in my Kestrel, set the correct bore height, chose the center-X AB custom curve profile, plugged in the velocity, and it just worked.