Ok, I shot a round robin of 3 rounds per load. Started with 45 gr as that worked in my last 7mm-08. Went up by .3 gr per load and stopped at 47 (1 gr over max by some books).
Brass was PPU
Primers BR2's

Velocity
45 gr = 2637,2655,2666
45.3 = 2670,2679,2667
45.6 = 2705,2709, 2693
45.9 = 2738,2675,2745
46.2 = 2745, 2768, 2736
46.5 = 2767, 2779, 2721
46.8 = 2788, 2794, 2795
47.0 = 2795, 2799, 2810

I'm seeing two relative flat spots - one at the 45.3-45.6 and another at the 46.8-47. All speeds measured by Magnetospeed.
With it on the barrel, shots were low by a couple of inches. Total group for all shots was about a 3" x 2" (high) group at 100.
With the temps at 97 today, I'm thinking the 46.8-47 group would be where to work on. I can shoot it again when temps get down oh, say, 30 degrees or so just to check. And, the group at 45 was just under an inch (sans-magnetospeed as breakin shots).

Thoughts?

Is the use of I4350 negotiable at all? All my 7-08's loved Varget. That being said, I think you could possibly go .5gr higher, to 47.5gr and see what happens as well. At those velocities I don't think you're bumping max pressure yet.

Just for the info I’d love to know what the difference in velocity is between heat of summer and much colder temps. I used 100 grain soft points over IMR4350 for about 4 years with no issues. Only a hunting gun and worked up all my loads during the heat of the summer.

I'm shocked you still have a stash of Nosler Solid base bullets.

Here you go redchevy

Groups, three by four inches at 100 yards?

H110 being so far down that list explains why pigs I kill in the summer with the 45 Colt are so much deader than winter pigs.

Thanks much for the info, don't believe I had ever stumbled across that before, will take a note of it. Using that as a rule I only lost about 38 fps from 90 degrees to 30 degrees using the IMR, H with those values would have been a little less than 1/2 that.

I bought a magnetospeed Saturday so will have to try it out. Was going to put it on my 10/22 out the back door, but got busy with other productive stuff.

Thanks again

Way I read that is all the shots of varying charges etc. were all fired into one group that was 3x2, but may be wrong.

redchevy, you are correct. All of the shots grouped in that space. I was limited to a max of 100 yards on this range.

So what was the size group for each individual powder charge?

The two best were under an inch. The upper 'node' was just over a half an inch, the lower 'node' was a little bit larger. All of the others were from an inch to an inch and a half.

Thanks, DStroud, for the list; very useful comparison.

As far as IMR 4350 goes, I have used it for over 30 years as my go-to all-purpose powder in five different cartridges. I have tested it extensively, mostly in a .270 Win, at a range of temperatures and found it to be very temperature sensitive, much more so than indicated in the list. I have measured velocity spreads of 80 to 100 fps between 30 and 90 degrees. For that reason, I am starting to use more Varget, H4350, and IMR 4451. I have found they are not "temperature-insensitive" as advertised, but about 1/3 as sensitive as IMR 4350.

I would assume a lot of the velocity swing could depend on your load development also. If you load to the middle of a node it might not have as big of an effect. If you just pick a powder charge and load it might have more of an effect.

Out of curiosity, do you guys trust the groups you shoot with a magneto speed on your barrel?

If I found a node, I'll pick the high side of the node when its in the summer, since you won't move higher in the node since its hot ( 90 to 95 degrees ), so that way you have a wider node when its cools off instead of picking the middle of the node.

No, so I don't clamp a Magnetospeed to the barrels.

Scott,

I found them at a gun show for $17.

I still have 100 6mm sp and only load for sight in and hunting.

What is your barrel length? My 18 1/2 inch barrel seems to be 100 fps slower than yours.

22"
Kimber Stainless synthetic