Trying a new load

[Clem Bronkoski]

I ran 2 ladder tests today for my 300WM using H4350. Bullets were the Berger 180 gr that I'm shooting with H1000 and Hornady 208 gr ELD Match.
I loaded charges with each bullet from 1 gr over starting load to 1 gr over max in .5 gr increments. During the test there were no excessive pressure signs for either bullet.
After all the velocities were recorded and analyzed i found that with the recorded velocities from the ELD-M the total spread from 64.5 gr to 65.5 gr was only 12 fps! That is a really flat node. I now loaded up 3 rounds each of 64.8, 65.0, 65.2, and 65.4 grains. Once I determine the best groups from these I'll start adjusting my seating depths in .003" increments.

 

[Dmagna]

What were the speeds and barrel length?

 

[Clem Bronkoski]

What were the speeds and barrel length?

26" barrel; 180s: 2926-3053 (65 - 68.5 hr)
208s; 2744-2857 (63 - 66.5 gr)

 

[Dmagna]

I would push the 208 a little harder. They seem a bit slow, should be able to get 3000

 

[Clem Bronkoski]

I would push the 208 a little harder. They seem a bit slow, should be able to get 3000

According to hodgdon load data 65.7gr is max (62K psi) and I loaded up to 66.5 gr - already almost a full grain over recommended max. Not showing any pressure signs but I know its up there. With my current load of 80.3 gr of H1000 I'm getting almost 3100 fps with the Berger 180s.
I'll take a stable load over speed every time. And like I said in the original post - with a full grain spread I'm only getting a velocity difference of 12 fps. That's really a big node.
Getting 3000 fps would really be pushing the pressure limits.

 

[Dmagna]

Are you using h4350 with the 208 or h1000? Hornady is 67.5 max on h4350 with the 208, that's why it's always good to run it till you see pressure. I also assume you are using fire formed brass as well.

 

[Clem Bronkoski]

Are you using h4350 with the 208 or h1000? Hornady is 67.5 max on h4350 with the 208, that's why it's always good to run it till you see pressure. I also assume you are using fire formed brass as well.

using H4350. The Hodgdon manual list 65.7 as max for the 208 ELD Match bullet. That's why I only went to 66.5 (almost a grain over max)
Thanks for the input but for now I think I'm going to stay in the node I found. That appears to be a very stable "zone" for the 208 and H4350 in my rifle.