Rings??

[Uchee creek gobblers]

I got the nwtf sx3 cantilever and havin a hard time finding rings to fit. Seems they don't wanna squeeze to the base. I'm putting a turkey pro on it. Anybody already have this setup? Or can help me with the rings?

[SCDieselDawg]

I've noticed this problem while working on other guns. I got lucky while trying another brand of rings that happened to fit.