Purpose of Hard Cast Hollow Base Wadcutters?

First topic message reminder :

I have come into some older 0.357" Dillon Hard Cast HBWC.  Test as BHN=16 using an artist's pencil set to scratch the lead.

Thought there was chance of the base breaking off if you push HBWC too fast and the purpose of the hollow base was to expand to seal the barrel better at lower pressures.  So what is the purpose of casting them BHN=16?  Should these be pushed faster than soft lead? 

The Hornady HBWC I typically use are 0.358" and much softer lead and go 725fps in my Colt Officers 2nd issue (7.5" barrel) using 2.8gr. Bullseye.  Really don't want to push the old revolver any more than that.  I suppose I could shoot them faster in my S&W 586, but I already have a 158gr SWC load and 2000 bullets for it.  Big question is what to do with these Dillon bullets??  I already have plenty of Hornady HBWCs on hand.

Perhaps Dillon Hard Cast bullets is the name of the division of Dillon that made bullets.

It may not have anything to do with them being cast.

What if SNS Casting or Laser Cast decided to market a swaged bullet? Would everyone assume that it had to have been cast?

DA/SA wrote:Perhaps Dillon Hard Cast bullets is the name of the division of Dillon that made bullets.

It may not have anything to do with them being cast.

What if SNS Casting or Laser Cast decided to market a swaged bullet? Would everyone assume that it had to have been cast?

If you look at the photo, these bullets were made by Meister Cast for Dillon, back when they were local to Dillon in AZ. They have since moved to the midwest, and I couldn't tell you if/how many ownership changes there may have been in the meantime.

There are a few companies that swage bullets for sale. I always thought it was due to the startup expense of a cold header press, conversion, dies, labor, materials, etc., as opposed to a Magma machine and some fondary bar lead, which while not inexpensive, it probably a little more forgiving of new business entrants. WAG on my part, tho.