I'm not surprised that it didn't perform well for you. I can add two kernels of knowledge from my own testing of 'match bullets'. I spent some time with the 240 SMK (among others) and can share my direct experiences.
First on shot placement. AIM for the shoulder, hit bone, that really helps initiate expansion, once it starts expanding it transfers energy more reliably. You have enough mass that it will carry through and break down the animal. Otherwise the 240 SMK demonstrated tumbling after about 8-10" of penetration and carried on base first in every test I ran. I found that impact velocity of an un-modified 240 SMK needed to be >2,200fps in order to open with any consistency. Even when you hit bone.
Second, 240 SMK is not intended to expand, and they are tough to get reliable expansion. In un-modified form they did not test well at all. would try to soften the bullet through annealing. It will result in more consistent expansion, down to lower velocity. Here is a link to a video that demonstrates rudimentary bullet annealing. It plain works.
https://youtu.be/AEisehCPtdw
I saw limited expansion of the 240 SMK in testing down to around 2,000 by annealing the 240 SMK and hitting bone. It still had a tendency to demonstrate tumbling inconsistently IMO, the center if mass is too far aft in that particular bullet.
I settled in on the 230 Berger OTM tactical in two of my rifles. I anneal the bullet forward of the bearing surface and see expansion down to 1,500 fps when I shoot to hit bone, penetration of 15" -18" and retained mass of 120-130g in wet newspaper media and expanded diameters of ~3/4".
Exit wounds on deer at that velocity are between 1" to 1-1/4" and bleed very freely. I have taken 14 white tail with this modified bullet. All but three fell DRT and the farthest any deer has made it was 23 yards from my .30/06 at about 230 yards. Two others mule kicked and fell dead within five yards of where they were hit.