In larger calibers, fmj's will work fine because of the added weight & sectional density
Look up sectional density. You must mean diameter. In any case, strongly disagree, especially with the idea of two holes being better. Sounds wildly irresponsible and like a manslaughter trial in the making when you dust the wanna be gangbanger and kill grandma behind him.
As a side note about why I strongly disagree, larger calibers are less disadvantaged as a FMJ because of their inherently larger wound channel with non expanding ammunition, but that's still suboptimal when you compare it to the outcome you'd get with hollowpoints. Just get the hollowpoints.