I have three rifles in 6.5 Creedmoor. Two of the three shoot the 140 grain bullets very well using H4350 from Lapua SRP brass, using CCI450 primers. Five shot group size (aggregate) of around 0.35” from the Savage 12 and the MPA.
The Remington 700 ADL sadly was a dud and shoots 0.7” to 0.9” groups, had burrs in the chamber and had to send it back, it is now a dedicated 200 yard capable hog hunting farm implement with permanent night vision.
When the Savage factory barrel was still fresh (<2,000 rounds), it shot 120 SMKs and 130 TMKs very well, as well as 140 Berger Hybrids and 142 SMKs, often into 0.25” three shot groups. Outperformed the rifles of my buddies who shoot F class. It was funny to watch the expression on their faces when they shot my cheap rifle and their groups got 30% smaller than i was capable of at the time.... At 600 yards on steel, the Bergers performed the best, i guess the high BC starts to show its worth at that distance. A rather pricey bullet - but highly recommended!
The new Berger 144 grain projectile apparently has better BC consistency compared to most other hollow point bullets (it is factory pointed), so probably the natural heir to the Berger Hybrid crown. Have used it and it shot small groups, with no fliers, using Reloder-16 (compressed load, need to vibrate the case to settle the powder and prevent a crunch if you load to mag length).
My MPA is throated for the Hornady 140 ELD-M bullet. Have used only 140 ELDMs, 140 Berger Hybrid factory anmo, and 142 SMKs so far. All shot well (but i have the superb Kinetics Solutions barrel tuner on this rifle, which makes it quick and easy to tune a load at the range). You can accomplish the same with optimized bullet seating, but it takes many more range trips... unless you buy an arbor press and the LE Wilson seater die, and that combo costs more than the tuner.
The Savage is now past 3,600 rounds and the lands have moved forward significantly, and still shoots the 147 ELD-Ms very well. The 147 ELD-M does not fit in the MPA, not enough freebore. Once the lands erode enough i will switch to longer heavier projectiles.
Have once shot a series of remarkable groups with RL-16 and 135 Atips, it was almost a dot drill, 2 shots per group, and later on measuring distance from aim point and calculated what a 5 shot group would have been, it appeared capable of 0.22” (at least in theory). Too expensive for my (kid-in-college) budget restrictions, so stopped using it for now. With RL-16 the load was compressed. [Have posted elsewhere how to deal with that.]
The trouble is eveybody is trying to get their hands on H4350, so it is always hard to find. I have used IMR4350 (not temp stabilized), and as long as you develop a winter and summer load, it works just about the same as H4350. Always in stock! My loads are 0.3 grain different compared to H4350, but that number is probably lot dependent.
My two best 6.5 CM rifles are not bullet picky, and pretty much anything between 120 and 156 grains works remarkably well. The R700 does not like any bullet, flawed chamber i think.
Once you optimized powder load for the middle of a wide flat spot in the speed graph, and once bullet seating (or tuner setting) is optimized to achieve good solid positive compensation, they all work. Bullet selection is driven by budget and how far you intend to shoot (high BC is desirable, and ability to transition to sub-sonic if shooting ELR) and what you are shooting at (steel vs paper vs animal hide). Pick a bullet that is easy to find, with high enough BC, good consistency in weight (and BC) and consistent base to ogive measurement, and one that does not have a reputation for blowing up halfway to the target. Hornady is getting some bad press for that recently, affecting 140 and 147 ELDMs. Then select a powder that is easy to find, is not compressed, and then stick with it. Unlike me who has to try everything new, and having to order a new barrel every 12-18 months.