Compression Ring to tight in new Piston?

[walnut417]

I have just purchased a new Wiseco Piston kit for my KX450F and the compression ring is too tight to fit into the groove. I tested the ring on the old piston and it fits in fine. I also tried the old ring in the new piston with no success, suggesting that the ring groove is to small. It appears to be clean enough. Wondering if anyone has encountered a similar issue??

[Wiseco]

Recommend contacting Wiseco customer service. 800.321.1364.