I understand you're bummed, but RRR has a threaded muzzle usually, so it ought to take an Ultradine and some kind of TechSight on pic rail at the receiver. At a significant additional expense, of course, but them's breaks.
https://ultradyneusa.com/product/c4-...-barrel-mount/
I also found a SeeAll to be a decent substitute for irons. It has basically the characteristics of irons: you must look through the sight and line it up with the target. It may also be more affordable than a set of irons, and being very small it clamps in the receiver rail. It is also surprisingly resistant to snow and rain (but not ice sadly).
https://www.seeallopensight.com/