Questions about Fracap Boot Sizing

Hello MFA. I'm generally skeptical of most footwear size charts, especially when it comes to converting EU and UK to US sizes. Does anyone have any advice on Fracap boots? I'm normally a size US 10 in most sneakers (US 11 in Nike though) and somewhere between a UK 10 and UK 9.5 in Solovair depending on the type of last the shoes or boots are made on. Any advice would be greatly appreciated.