In answer to the OPs orginal question:
Laser Cast bullets are VERY hard cast. Must be all that magic silver! I do use them in my 30-30 rifle and they work well in the Marlin micro groove.
They have a BHN of 24 BHN which is really hard. Some companies do this to try and prevent leading but hardness is not the only thing. Yes. Size matters
So their explanation of obturation is a bit different than MBC.,
MBC uses 12 BHN for Cowboy loads, (soft shooting powder puff loads so the bullet will expand at low pressure and velocity and not lead the barrel.
The 18 BHN is harder for high pressure and faster velocity.
I have asked Brad several times at MBC that this does not make sens with the230 gr Soft ball for 45 ACP. They make that in a 18 BHN which is the same as a the Magnum bullets?? I special order the 230 RN made in 12 BHN alloy as my loads are not even 800 fps, Some of the other 45 ACP bullets are the softer lead also.
It's all a way to avoid leading and sealing the barrel. The new coated bullets are the same alloy, the coating is the lube which also eliminates leading.
http://www.laser-cast.com/files/Understanding_bullet_obturation.pdf