300 Win Mag Load Development

[MattM]

I’ve been doing a lot of reading on here about load development and have been working on 4 of my rifles using the methods posted on here....specifically the method of 3 shot groups and then analyzing the targets to determine where the accuracy node might be. I believe this was posted by Erik Cortina, however I might be wrong on that...someone please correct me if i’m wrong.

One of my rifles is a Savage in 300 Win Mag with a heavy 26” barrel. I started the test at 73.5gr of H1000 pushing a 195 gr Sierra Tipped Match King, moving the powder charge by 0.5 until I hit 78.0gr. Due to the limited magazine length, the closest I could get to the lands was 0.091”. Below are the pictures of the groups from 100 yards.

I was hoping some of the group members could help me determine where to look for the accuracy node. I will be shooting some of these groups again such as the 77.0 gr. I appreciate any help on this!

 

[Zero333]

77 gr

Load and shoot some 5 shot groups with that load to confirm its stable.

I would leave the OAL the way it is.

 

[muleman69]

[QUOTE="MattM,![/QUOTE] 77 grain looks great, any bolt lift or pressure marks at 78?

 

[MattM]

There was no pressure signs or sticky bolt lift at 78.0 grains. I am definitely going to be shooting the 77.0 grain again to verify the load. At 77.0 grains the chronograph showed an average of 2874 FPS with a standard deviation of 43.6....not exactly the consisentcy I am looking for. The first shot measured 2926 FPS, second shot 2837 FPS and the third shot was 2859 FPS. Not sure if the chronograph was entirely accurate with the first shot.

The 76.0 grain grouping had a standard deviation of 9 and the group measured 0.582”. Would I be better off looking to this group because of the lower standard deviation?

Thanks again for all the input!

 

[muleman69]

76 might be worth trying again even 76.5,or work up from 76 to77 if a person has the time

 

[Zero333]

Once I stopped gathering Chrono data and only relied on the target for input,. My groups been smaller and more consistent.

Unless you're planning on shooting beyond 1,000 yards, nevermind the Chrono.

 

[seymour fish]

I’ve been doing a lot of reading on here about load development and have been working on 4 of my rifles using the methods posted on here....specifically the method of 3 shot groups and then analyzing the targets to determine where the accuracy node might be. I believe this was posted by Erik Cortina, however I might be wrong on that...someone please correct me if i’m wrong.

One of my rifles is a Savage in 300 Win Mag with a heavy 26” barrel. I started the test at 73.5gr of H1000 pushing a 195 gr Sierra Tipped Match King, moving the powder charge by 0.5 until I hit 78.0gr. Due to the limited magazine length, the closest I could get to the lands was 0.091”. Below are the pictures of the groups from 100 yards.

I was hoping some of the group members could help me determine where to look for the accuracy node. I will be shooting some of these groups again such as the 77.0 gr. I appreciate any help on this!

From 76.5 to 77, you have negative vertical displacement. At 77.5 you have scatter. The SD/ES is “unhappy”. None of this is desirable. Don’t know how close you are to “pressure”, but going up carefully might show you something better. Presuming an adequate primer, if no improvement, perhaps a change in powder would benefit

 

[Zero333]

I prefer 215m over cci250.
When I switched to 215m from cci250 groups got smaller.