Problem is I don't know how to test results without shooting deer and I don't shoot but one or two a year. Will take me 20 years to find the right one
HaHa!! You can do some internet research and I bet you'll find some good recommendations for a more reliable 280 load. If you want to have a project during the off season, you can do your own testing for bullet penetration and bullet integrity. Over a 4 year span, I did a science fair project w/ my son where we tested 30 caliber ballistic tip bullets of varying wts (125, 150, 165 and 180 gr) by shooting them into bundles of newspaper that had been soaked in water for 6 hours. Granted, a deer is not made of wet newspaper, but you can find out a lot by comparing the results of different bullets. IIRC, the 125 gr BT penetrated something like 14"? Even the lowly 22LR penetrated 8". Save a couple of your 150 gr CLs. After doing your research, buy a box or two of the best 280 loads. Shoot a few rounds each of the CL, the new bullets and your trusty 30-06. Shoot at close range as that'll put more stress on the bullet. A bullet that holds together at close range will also do so at further distances. Be prepared for the 180 gr '06 to penetrate deeper than the others. Measure the penetration, retained wt of each bullets and examine each bullet. I bet you can find a load that penetrates deeper, and retains its jacket better. than the CL, but probably not quite as deep as the '06. Won't take long to do the test and you'll find out a LOT about your bullets.
In addition, when you skin a deer, open the chest (assuming it was shot in the chest) and examine the wound itself, especially the entrance/exit holes.
The key to killing deer is not so much the cartridge that's used, but the bullet that's used.