If it shoot's jacketed well it should shoot cast, If you are concerned about the "rough spot" you might look into fire lapping the bore. The bottom driving band along with the lube should form a good seal as long as you keep the pressures low.
Size them .225 if that's the H&I die you have, if it's .224 then look into hand lubing or pan lubing and shooting them unsized.
also consider a pinch of "dacron" AKS poly filler, the stuff thats in stuffed toys, or some dryer lint , just something to seperate the powder from the bullet base which might have some lube on it
I tried three 55 + gn boolits in my T/C Contender Hornet, 5.0 gn of Unique was just a stouter that a simular equipped 22 LR