Ian,
If that 1.47" puts one hole through the paper at the 1K it sure will start a lot of head scratching.

Personally I think it will get the job done.
I don't have one that long but I would use my 1.42"
I have one DD at 1.4" , my first mould that gave me problems on and off, but gave very good accuracy if I breach seated the bullet because of the long freebore my chamber has I would let you use to cast a bunch to try. if yours gives you a problem.