I have both,a 10FCP and a 12FLV.
The 10FCP has always shot better than the 12FLV. Shooting the same bullets in handloads taylored to each rifle,the 10 always shot around 1/4-1/2 moa better than the 12 at any range.
The model 10 has always shot great-moa or better,usually better.The model 12 shot good,but seemed to struggle getting sub-moa groups with most weights/types of bullets.
It may just be my experience,but I ended up using the 12FLV for my switch barrel gun,and use it for my 7mm/08 and 6.5 Creedmoor barrels now.
I also have an older 12FLVSS 223,it has always been an excellent shooting rifle,as have both of the 110FLP rifles I own in 25/06 and 300WM.