what grain bullet[round nose, spire point etc.] and type of powder would be suitable for cow elk.

If you're a handloader the 154 to 162 grain bullets will do the job nicely.

Either can be pushed 2500'/sec from a 22" barrel.....

I have found the 160 or 175-grain Nosler Partition bullet to be very effective when used in the 7X57mm for elk. You could use a round-nose in 175 grain weight also, but this bullet is not as good as a pointed one for shooting beyond 250 yards or so in the 7X57mm. In a strong action, the 160 grain can be loaded to over 2600 FPS, and is good on animals as large as elk, cow or bull!!

For cow elk I would use the 150 gr. Nosler Partition. Look at the Nosler reloading guide #4. You will probably have best success with IMR4350 or H4350.

I just read a good Artical by Rick Jamison of Shooting times. The artical was on reloading the 30-06 but he states that his figures for sectional density crosses all calibers. He recommends a bullet with a sectional density of 260 or more for elk. In 7mm anything over 150 grain bullets are well into that range. For Moose or big bears he starts with a sectional density of 300. For deer size game he says a sectional density os 210 or higher. I have always subscribed to the sectional density of bullets when selectin a bullet weight for different hunting projects.