Fusions leave a good trail for me.None further than 40 yards with the majority looking like you slung it out a bucket with a big paint brush…
I do not shoot a 6.5 CM, but Federal Fusions do very well for me out of my 270 and 308. I have only had 2 cases over the past 12 years or so where I did not get a complete pass through and both were on big bodied bucks shot through both front shoulders. In both cases, the bullet was found just under the skin on the opposite side.
You need a good pass through shot to get a blood trail. If you hit them high in the ribs, it sometimes takes a while to get a blood trail because the body cavity must fill up before blood can exit the entry/exit holes. If you are patient, place an accurate shot in the high shoulder - the deer will drop in their tracks most of the time and there is no blood trail.
If you shoot one through the heart, the deer will have about 8 seconds before they fall over due to lack of blood/oxygen to the brain. They seldom go 40 yards with a good heart shot. Double lung, you will get a good frothy bright red blood trail and find the deer within 100 yards. Only hit one lung, they may go 200 yards.
Gut shot - will typically give a complete pass through regardless of bullet. Blood trailing can be difficult - back out at least 4 hours and then kick yourself for making a poor shot.