I had 2 loads that shot closely. 3- 21.5gr. 240 and 295gr. SWC's, spaced with 3-180gr. Sierra JHCavities with 26.0gr. 2400.

The 250s I found, would pen. the fender skirts of a 1956 Buick and break the water jacket and most times, crack the block.
The 180's would do the same and more damage to cylinder walls I finally found, as well as being best as penning the trunk, back seat cross support, then rear seat, front seat - 1/2" plywood human silhouette, pen the dash and kill the carburetor, all with one shot. The 250's gave me 5/6 hits on the ram silhouette at 300 meters from a sitting, back rest position. They could not be beat for long range work. We had (my bro and I) lots of penetration fun testing on wrecked demolition cars in the windshields and the silhouettes behind them were easy for straight line penetrations with either choice of ammo. Other car tests were done with an original .45/75 model 76 Winchester - dang - he should have kept that one, along with an original .45 2.4" Sharps model 74 in good shape. We use 525gr. RN's from my .45/70 mould in it and had a blast on cars - you guys gotta try that sometime - give you new faith in "heavy" cast bullets.