When we designed a .45acp HP for short barrel pistols (3.5") we used straight wheel weights. It was soft enough to get reliable expansion in beef at around 750fps. Yes, the final tests were done with a large beef roast with two layers of denim over it. It was over 10" penetration and expansion to almost 3/4". The bullets would also penetrate/break a 2" wet oak dowel. The mold used was the Lee 228RN. The key was the design of the HP. We went through 5 or 6 different designs to get one that worked and did not plug up with the cloth. Final bullet weight was just under 200gn. This was done 30 years ago. Since then better factory HPs became available so we dropped the project.
And, yes, one design did badly in the chambering process, deforming when it hit the ramp.
So, short answer is, you can just go with WW instead of pure lead. Whichever is easier for you will work.