Cast Lead Thread ?

[Oldbloke]

I was given about 300 GC'd 224 lubed bullets. 54gr IIRC.

I tried them in my 223 with 7.0gr AS50n. 7.5gr works well with jacketed bullets for close work. But these cast ones were all over the target. I figure it's because they are fairly soft.

So, thinking try again with abt 5gr AS50n to slow them down.
I figure will be about 1600fps.

But will I need a filler?
If so, any suggestions?
Any other suggestions?