I've read two or three articles about good choices for loads for the 6.5CM, but none of them seem to feature any of the powders I have on hand. Has anyone worked up any loads for RL-15,19,22 or H4831 or IMR 4350? Or are these too old fashioned for a new -fangled cartridge like the CM? Some of those seemed to work for my .250 Savage and 257 Rbts--how much different can a CM be?

There's data out there, just gotta look for it. Try the hodgdon and alliant sites. Sierra has this online:

https://sierrabullets.files.wo...or-data-final-as.pdf

A couple of the powders you mentioned are pretty slow, and would work best with a heavy bullet.

there is a 6.5 c.m. web site somewhere. reading there h4350 seems to be the best powder by a stretch. i worked up loads for a friends savage sabre with aa4350. it was easily sub-half inch for 3 shot groups. h 4350 and hybrid 100v are the two slowest listed in the annual manual.

H4350, Hybrid 100V and RL17 seem to produce top velocities, especially with bullets 120 grains and above. That is good since I have a ton of RL17 on hand. I take possession of my 6.5 Creedmoor in a couple of weeks.

IMR's data shows IMR4360 and H4350 producing similar results. I have noted that best accuracy is usually reported as being several grains below max in most cases.

Despite what everybody says about the 4350s, I have found neither works very well in my 6.5 CM, with 140 Sierra MK bullet, that is.

Best results have been with RL17, and, believe it or not, 4064. Sierra has load data on their site that shows loads using 4064.

Tried H414 as well, results were similar to the 4350s.

IMR 4451 works very well too.

I have a .260 Reminton and H4831 gives great results with 140 gr Sierra Game Kings and loaded so that the powder just crunches when the bullet is seated (45.5 gr for my case - yours would likely be a bit less). Seated 0.015" off the lands.

It's easy for us to share our pet loads and I have no doubt that y'all are producing the results of which you speak BUT every rifle is an island (or a fine woman) and you've got to find what YOUR rifle likes.

My 6.5 Creedmoor rifle is very partial to R-17 with 129,130 and 143 grain bullets.

I have a couple newly purchased cans of H4350, but alas, I have not tried it yet, although some say it's the bees knees.

Zeke

With H4350 start with 41.5gr and work your way up. Seat the bullets close to the lands, but seating depth may vary concerning the bullets used. For my rifle .010 off the lands works with 140gr. Berger VLD.

I have read that RL16 is good but it is unobtainable for me. IMR Enduron 4451 works a lot like H4350.

Lapua 120 Scenars work good with 43.5gr of H4350.