OP, others have said most of what needs to be said on this thread.
The 6.5 CM is a fine round and you can have a lot of fun with it, but, as with everything, it has its limitations.
I will make some predictions:
- You will be shooting out to a mile with your 6.5 on a calm day and get some hits and be happy.
- You will go out on a day where the wind is gusty and unpredictable, and be lucky to walk away with a couple hits out of 50.
- You will say to yourself, "well, I want something bigger for just this type of condition... so I can shoot in the wind better."
- You go build a rifle with a bigger caliber.
- You are happier at a mile, but say to yourself, "I can shoot farther now! I want to try 2000 yards."
- You will go out on a calm day and get some hits at 2000 yards and be happy.
- You will go out on a day where the wind is gusty and unpredictable, and be lucky to walk away with a couple hits out of 50.
- You will say to yourself, "well, I want something bigger for just this type of condition... so I can shoot in the wind better."
- You go build... well, you get the picture.
It's an addiction.
Bottom line is to decide where and what ranges you want to shoot at and build a rifle that best matches those conditions. Can a 6.5 shoot a mile and a half or farther? Yes. Is it practical? No. Can a big 30 cal shoot a couple miles? Yes. Is it practical? No.
For me, I like to be challenged, but I prefer not to be gimped. I want to be challenged by the conditions, not by the equipment. I don't want to go out and shoot a bunch of rounds for which I can see neither the hits nor misses and I'm just shooting blind.
As an example, I'll take my 6 BRA with me when I go to do some ELR. If the conditions are right (and there's dry ground around the target for the splash), I might take shots with it at 1500 or a mile. If not, it's a fool's errand and a waste of components. Instead, I'll set closer targets and shoot unsupported, off a fence post, or do something else to make it challenging - and leave the longer range stuff for my 300 PRC.