The .22-250 is a necked down .250 Savage case, and both are shorter than a .308 Winchester.
I've necked .308s to make .22-250s. The purpose was to provide a very thick neck which could be neck-turned in order to produce a fitted neck condition in a factory style chamber. The rifle was quite accurate, and had relatively tight dimensions in all aspects except a very generous neck diameter. I was in my "benchrest" phase of this illness.
I necked the .308 to .260, then to .243, then to .22-250. It was a VERY tedious process and case losses were high. The .22-250 neck formed in this manner is actually a portion of the former .308's case wall/shoulder junction and is VERY thick. Trying to reform this area to meet the .22-250 shoulders often resulted in case collapse.
In retrospect, a .250 Savage F/L sizer would have helped, because I could have reformed the shoulder and neck in separate steps, thus with less pressure. It would have also suited my own purposes as well had I started with .243 brass, since the body thickness that ends up being the .22-250's neck is about that of a .308.
Realistically and even if the .308 brass was free, by the time one procures the several intermediate dies and neck turning/reaming equipment necessary to make this work, and pays even $1/hour for labor, it would be far cheaper to just buy brand new .22-250 brass.
After ruining about 30 cases, I did produce about 20 usable cases in about 30 hours that showed no accuracy improvement, so the ill-conceived idea was scrapped.