I just had a 338 Norma magnum built and am in the early phases of my load work for it. If others here that have loaded for the 338 NM could give some feedback it would be greatly appreciated.
The rifle is built on a Defiance Deviant action with a Bartlien barrel (27” heavy varmint contour @ 1:9.3” twist).
I went with 300 grain Berger bullets to start and H1000 powder as this seems to be a very common combo in the 87-88 grain range at 2700+ fps. I started very conservatively, and the loads and velocities are as follows:
300 grain Berger Hybrid OTM
H1000
Fed 215M
New un-fired Norma brass
2.836” to ogive (0.018” jump)
1) 81.0 gn @ 2584 fps
2) 81.5 gn @ 2595 fps
3) 81.8 gn @ 2618 fps
New Lot of powder used (velocities dropped)
4) 82.1 gn 2540 fps
5) 82.5 gn 2590 fps
6) 82.8 gn @ 2585 fps
7) 83.1 gn @ 2610 fps
8) 83.4 gn @ 2620 fps
9) 83.7 gn @ 2627 fps
10) 84.1 gn @ 2630 fps
This was over a couple of range sessions. I am still ~4 grains and 100 fps below what most people are getting with H1000 and I am starting to see signs of pressure with flatish looking primers, no cratering of the primers though and no stiff bolt lift yet. All of these groups were close to 1/2” at 100 yards with SD’s from 4-12. I still have a little room to go up in charge but don’t think I will get close to 87-88 grains without high pressure. I am wondering if I may have a tight barrel and that is why I am seeing pressure earlier than most?
I also tried the same loads but substituted Reloader 33 for H1000.
300 grain Berger Hybrid OTM
Reloader 33
Fed 215M
New un-fired Norma brass
2.836” to ogive (0.018” jump)
Those loads were:
1) 91.0 gn 2559 fps
2) 91.5 gn 2574 fps
3) 92.0 gn @ 2601 fps
4) 92.5 gn @ 2610 fps
5) 93.0 gn @ 2642 fps
The Reloader 33 produced these velocities with no real signs of pressure but the groups were not as promising as with H1000 and the SD’s averaged higher at 15-20.
Thanks for any feedback or advice on these loads and further load development as it is greatly appreciated.
The rifle is built on a Defiance Deviant action with a Bartlien barrel (27” heavy varmint contour @ 1:9.3” twist).
I went with 300 grain Berger bullets to start and H1000 powder as this seems to be a very common combo in the 87-88 grain range at 2700+ fps. I started very conservatively, and the loads and velocities are as follows:
300 grain Berger Hybrid OTM
H1000
Fed 215M
New un-fired Norma brass
2.836” to ogive (0.018” jump)
1) 81.0 gn @ 2584 fps
2) 81.5 gn @ 2595 fps
3) 81.8 gn @ 2618 fps
New Lot of powder used (velocities dropped)
4) 82.1 gn 2540 fps
5) 82.5 gn 2590 fps
6) 82.8 gn @ 2585 fps
7) 83.1 gn @ 2610 fps
8) 83.4 gn @ 2620 fps
9) 83.7 gn @ 2627 fps
10) 84.1 gn @ 2630 fps
This was over a couple of range sessions. I am still ~4 grains and 100 fps below what most people are getting with H1000 and I am starting to see signs of pressure with flatish looking primers, no cratering of the primers though and no stiff bolt lift yet. All of these groups were close to 1/2” at 100 yards with SD’s from 4-12. I still have a little room to go up in charge but don’t think I will get close to 87-88 grains without high pressure. I am wondering if I may have a tight barrel and that is why I am seeing pressure earlier than most?
I also tried the same loads but substituted Reloader 33 for H1000.
300 grain Berger Hybrid OTM
Reloader 33
Fed 215M
New un-fired Norma brass
2.836” to ogive (0.018” jump)
Those loads were:
1) 91.0 gn 2559 fps
2) 91.5 gn 2574 fps
3) 92.0 gn @ 2601 fps
4) 92.5 gn @ 2610 fps
5) 93.0 gn @ 2642 fps
The Reloader 33 produced these velocities with no real signs of pressure but the groups were not as promising as with H1000 and the SD’s averaged higher at 15-20.
Thanks for any feedback or advice on these loads and further load development as it is greatly appreciated.
I achieve much better results from using the 250 grain Match and VLD hunting bullets than from any one of the 300 grain bullets. The 250 grain bullets are a perfect match for the 100 grain capacity cases. 
