Being stuck here in California I have been loading and shooting mono bullets for the past 6 or 7 years. My experience with them is that the mainstream brands, Hornady, Barnes etc. all shoot very well for accuracy but for game hunting they are limited. The reason being is that they go through and mushroom ok but most of their energy is expelled after the exit. This deep penetration is great for class 3 game but has issues with deer and other smaller game animals. Without the weight and energy disbursement while passing through most deer etc. are able to bolt and run long distances even with good hits through vitals. There have been a few exceptions but if you take some time and read the tests done by Ballisiticstudies.com they show the same results that my research has. Their recommendation is to aim forward so as to break shoulder bone to help with internal energy damage. In speaking with numerous hunting guides they all have come to the same conclusion as well. A perfect mushroom that goes through like a dart will many times lead to hours of tracking, often with sparse blood trails. There are a few mono bullets that have been addressing the energy issues. The bullets from Lehigh Defense and Cutting Edge are designed to break off several smaller projectiles after penetration so as to expel more energy internally and open larger wound channels. I also see that Hammer has begun to offer a similar bullet design as well but they have not been readily available to order from their website so I have not personally tested them yet. Once they are listed I will give them a try in a few calibers and see how they will do. On class 3 game where deep penetration is necessary the mainstream mono bullets do well as they offer deep penetration.
Some interesting reading and videos are available here:
https://www.ballisticstudies.com/Knowledgebase/Homogenous+copper+bullets+can+be+inhumane.html Be aware that there will be some graphic iomages and videos that show their research.