338/300 rum using us869

[jdg300rum]

Has anyone tried this combination 338-300rum with us 869 and 300 gr smk? If so what was the starting loads and max loads? Velocities?

 

[sebastian3784]

I have had better luck with the 300MK using Retumbo or H1000. 92 grains of either as their burn rates are close. Start slightly lower and work up due to chamber variances.

 

[royinidaho]

I don't know what Lot # I'm using.

In my 338RUM 101gr behind the 300smk produced 2730 FPS.

The label says 338 Lapua & 104 grains 300gr Sierra HPBT (I suppose that's the SMK) goes 2677.

Load density is good and SD and ES both were less than 1, accuracy was a bug hole's bug hole si I quit shootin' and went huntin'.

You could start @ say 98 amd work up one grain at a time and be comfortable.

Keep us posted....

 

[jdg300rum]

I tried some us869 in the 338/300 started with 98 grains and worked up to 108. The velocity at 108 grains was 2850. Shot an excellent group. I am going to try the h-1000 too.