If i were going to make a 6.5MM on a Howa 1500 action (no matter what stamping is on it's side) I'd do it in 6.5X55 not 6.5 CM.
The magazine is long enough for the Swede. The 6.5CM was invented to reproduce Swede ballistics, but fit in a short NATO length magazine. It comes very close, but it never beats the Swede in the same barrel lengths at the same pressures.
Howa even makes one as a factory option in 6.5X55.
I do have a high degree of respect for the 6.5Creedmoor, but frankly, the Howa is the wrong action to use for it. The Swede is a better fit and does all the CM will do, plus a little bit more.
If I were going to make a bolt action (or buy one) in 6.5 Creedmoor it would be a Ruger Precision Rifle, or a re-barreled Ruger Scout, or a re-barreled Mossberg MVP. These 3 have NATO length detachable magazines.
Any action that will take a 308 length cartridge with a little bit of room in the front of the box I'd barrel to a 260 Remington instead of a CM. If it's close---- then I'd go with the 6.5 CM
Any one that takes a 57MM length Mauser length cartridge (6MM Rem, 257 Roberts, 6.5X55, 6.5X57, 7X57 or 8X57 9X57 or 9.3X57) I'd barrel in 6.5x55 Swede. Of the 3 best 6.5MM cartridges (260, 6.5CM and 6.5X55)I think the old Swede is still the best of the bunch. By a very small margin I'll admit, but it still is on top. As accurate as any and a slight bit faster.
Any of the bolt actions available that takes a 30-06 length cartridge I'd barrel in 6.5-06,---------- or more likely I'd just go with a 270 Winchester.
Yes yes....I know. The BC of the 6.5 bullet is higher. But not high enough to overcome the extra 300 FPS velocity the 270 gives me with the same bullet weight, and the 270 is also available in heavier bullet weights at faster speeds, so that extra edge of the higher BC in the 6.5CM has to cover a LOT of ground before it catches up with the 270
But that's just me.
I have shot the throats out of two 270 barrels and I am working on the 3rd one now, so I know the trajectory pretty well. I can't see any reason (personally) for ME to re-learn a different trajectory curve, especially when the 2 don't match each other until I get farther ways than I'll shoot game anyway.
If I ever decide to make a CM for myself I will do it on an AR-10 size auto loader with a 1-8" twist. That would be interesting to me.