.338 Norma Magnum and IMR 7828ssc

[codyadams]

So I have a .338 Norma Magnum that is almost finished.....the only thing I'm waiting on is my stock from Manners, which they said it should be going from inletting to finishing any day now, so I am prepping for load development, and will hopefully have some rounds down range and a good stable load for late season cow/calf elk. I plan on running a diet of 285 Hammer Hunters and 300 Bergers Elite Hunters, the Hammers for hunting and the Bergers for everything else, since they are half the cost.

So I want to break the barrel in with IMR 7828ssc and the box of Bergers I have and get a good load with them, then start load development with the N570 and the 285 Hammers.

So anyone have some load data with 300 Bergers and IMR 7828ssc?

 

[codyadams]

Anyone?? What about data with N570 and 285's??

 

[codyadams]

Well I'll post it here and in the .338 nm reloading thread in case someone else wants to know. I have a workup right now with the 300 Berger EH of 80, 81, 82, 83, 84, and 84.5 grains to look for pressure. I am shooting it in a 24" barrel. H1000 ended up around 2675 @ 88 grains, which according to quick load was about max CIP pressure, 63,000 psi. Once I finish my velocity and accuracy testing I'll report back what I find.

 

[codyadams]

Results were as follows:

300 Berger Elite Hunter, .020" off (3.680" OAL)
IMR 7828ssc
Peterson Brass
GM215M

80 - 2539
81 - 2578
82 - 2615
83 - 2662
84 - 2669
84.5 - 2714

Just started to see the first signs of pressure in the form of a light primer crater at 84 grains, and 84.5 had a significant jump in velocity, I only shot one of those, didn't bother with the group as it was too hot. No bolt lift, ejector mark or anything like that was present on any, but Peterson and Lapua brass in these large diameter cases hide pressure very well, and usually don't show signs until you are well over pressure, which I want to avoid as this is being ran on a Remington 700 action.

80 grains was around .75", same with 83 grains, and 84 was slightly larger. 81 and 82 showed poor accuracy, 1.5" or a little more. Not as good of results as H1000 as far as accuracy, but I still need to do a seating depth test to determine where it wants to be. Seems like there is accuracy around 2540 and again up at 2660-2670, I may explore that a little bit while finishing getting the barrel settled in, I have 49 rounds fired so far.