I have to agree with Mike, mine is .177 cal I’m only testing at 20’ with all groups less that 1/2" so far it likes Miesterkuglens best but not by much.
i got swamp fox liberator ll On the Rex, I had it laying around but really like it,, CVlife makes a pretty good red dot that I have on 3 of my other pistols , at about $$135 or so a pop it works pretty good, I ALSO TOOK MY GRIPS OFF AND Greased the springs down with Moly, Helped a little . I know some said the Rex felt like a P 16 but not as a fine fit ,, I say the Rex feels like a upgraded lightened PP 750,,, Mike
Got the Reximex RP in .177 from Krale first week in 2025. Has only filled it twice, but so far it is holding air, and it shoots well. Yes, one have to use some force to get the mag in place, but I believe the fit will become better after some use (plain plastic meeting aluminum........ something has to give in over time). For me, this is an excellent setup (small, and under 1.5 kg fully rigged), and will fit perfectly in any backpack.
Today I sanded (very slightly), the two lifted lines at the backside of the magazines. That helped a lot, and the mags now goes far better into place. Do not take much off! By the way, the pistol shoots fine, and for the money - and the plastic finish - I am impressed.