338 Norma Reloading Data

highdrum

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Ok, so my magneto speed went on the fritz, was a frustrating day, didn't accomplish much ha ha. I ended up ditching N570 as I only have about 1.5 lbs left, and I'm not having any luck getting more, though 91 grains did shoot pretty well, at around 2860 I believe. I bought a labradar, just got out today, and did a max pressure work up with Retumbo and IMR7828ssc, ended up with this -

250 SBDII
Peterson brass
GM215M
.025 off
24" Lilja 4 groove barrel

RETUMBO -
91 - 2862
92 - 2903
93 - 2924
94 - 2963 - discontinued, entire group right at 1 MOA ctc, with 91-93 being sub .75" @100

IMR7828ssc -
86 - 2922
87 - 2962 - discontinued, the two were 2" apart

If I was going to continue IMR7828ssc, I would start around 83 grains and work up from there, probably around 2820-2830 to start. I'm going to continue my work up with retumbo, likely doing a ladder from 91 to 93.
This is standard 338nm? I'm kinda wondering where my 338 rum w/ 28" barrel would run. I have accuracy with N570 and 300s @ 2850fps.
 

codyadams

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This is standard 338nm? I'm kinda wondering where my 338 rum w/ 28" barrel would run. I have accuracy with N570 and 300s @ 2850fps.
Ya, standard Norma, 24" Lilja barrel. I tend to run my loads pretty conservative as this is built on a Remington action, I have never once seen ejector marks or heavy bolt lift, only light primer cratering on a couple loads, and I mean light. With a 28" standard .338 NM built on a stiller TAC .338 action, I ran the 300 Bergers up to 2925+ fps with Retumbo, and still didn't see ejector marks, increased bolt lift, clickers or anything, I stopped because I knew the extreme velocity could only be due to high pressures. The ADG brass is, I would nearly say, dangerously tough stuff. You can run stupidly high pressure, and other than the velocity and possibly primer catering, have no signs. I am starting my 8th firing of this 50 pieces of Peterson brass in my .338 NM, and have no signs of wear, primer pockets feel new, no separations, no cracked necks, nothing, and I have not annealed brass as I do not have an annealer yet. When funds allow it, I will....

I run that same 28" .338 NM at 2850 with 300 Bergers, using Retumbo. It is a very accurate load in that gun. From what I have seen, a .338 rum and .338 Norma are pretty similar. When it is time for another barrel, I am going to go .338 NM improved, I think that would boost performance a bit, and be an overall sexy looking cartridge ha ha
 

Lonewolf74

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Hey Cody, I seen a few post back that you had some loads done up in N570 and N565. I know you also said you discontinued development with the 570 cus of getting low but I was wondering how the load was panning out velocity wise? Also how was the 565 stacking up? I got a few lbs of 565 but I haven’t played with it in anything yet.

I have several lbs of 570 stashed but I’m actually hoping to find some imr 7977 and 8133 to test and really hoping it runs great cus I’m sort of tired of always trying to find 570 and 565. Before the current market situation I could find the imr powders everywhere.
 

codyadams

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Hey Cody, I seen a few post back that you had some loads done up in N570 and N565. I know you also said you discontinued development with the 570 cus of getting low but I was wondering how the load was panning out velocity wise? Also how was the 565 stacking up? I got a few lbs of 565 but I haven’t played with it in anything yet.

I have several lbs of 570 stashed but I’m actually hoping to find some imr 7977 and 8133 to test and really hoping it runs great cus I’m sort of tired of always trying to find 570 and 565. Before the current market situation I could find the imr powders everywhere.
I got through most of the N570, not all, and started N565 but that is where my magnetospeed bit the dust. Velocities were as follows -

250 SBDII
Peterson brass
GM215M
.025" off

N570
91 - 2832
92 - 2824
93 - 2849
94 - 2886
95 - 2890

N565
86 - 2719
Then my magnetospeed died. Lol
 

codyadams

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Ok, so I was getting ahead of myself, and forgot to do a seating depth test, so instead of a ladder I checked seating depth, and found out that in my gun, this 250 SDBII HATES being close to the lands ha ha. Instead of writing it all out, I'll just post photos to see. Groups were shot at 250 yards.

20210519_141245.jpg
20210519_141328.jpg


On the target, I listed that I started at .015" off, but I really started at .010" off. Anyway, as you can see, .010" off was terrible, and .030 wasn't great either. After that, they all went down to sub MOA, with .050 being right at or just over half MOA, and .110" not far behind it. You can see velocities drop as well from the bullet having farther to move so as to drop pressure before hitting the lands.

Now - next thing is a 600+ yard ladder. Already have them loaded up.
 
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codyadams

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Had pretty good results with my 600 yard ladder test, from the pics below you can see that there seems to be a pretty good node around 91.2 through 92.4 before it jumps significantly. The wind was pretty shifty, going anywhere from almost non existent up to 6 or 7 at times, I held off for three rounds but decided to just have the same windage hold and see how much it affected it, so I don't put too much weight in the lateral movement. But 91.5-92.4 had less than 1 inch of vertical, even with 43 fps velocity variance over almost a full grain of powder.

It seems like it may have been starting to settle down about at 93.2 and 93.5 in the low 2900 fps range, I may play with that a little bit, as the velocity there seems pretty stable too, but if not, 92 grains around 2875 would probably be sufficient.

20210522_082125.jpg
20210522_170114.jpg
 

SheepShapeAK

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So after looking through some of the notes posted here for load data, this is the ladder test I’m going with.

If any of you see anything that looks off, please chime in.

Defiance Deviant Tactical action with a 26” Bartlein 5R 9.3 twist.

Peterson Brass (First Run .338 NM)
Primer - GM215M
Bullet - 275gn Badlands Bulldozer II
Powders - H1000 and IMR 7828 SSC

Going up in .5 grain increments.

H1000 - Start 83 grains / End 87.5 grains
IMR 7828 SSC - Start 80 grains / End 84.5 grains

Also, this is what was posted about the first run cases. Not sure how much difference it will make, since after looking at some of the loads you’re running, it seems like I may even be a little on the low end.


NOTICE - THIS IS THE FIRST RUN: Due to popular demand, Peterson Cartridge released its .300 Norma Magnum and .338 Norma Magnum casings in the spring of 2018. When Peterson designed these casings, it chose to use the same parent casing as its .338 Lapua Magnum casing. As a result, Peterson chose to keep the major diameter of the casing (the diameter just above the extraction groove) the same size as its .338 Lapua Magnum casings. That diameter is .580”. Since Peterson has never had any complaints about excessive major diameter growth, or primer pocket loosening in its .338 Lapua Magnum casings, they believed that to be a fine decision.

After releasing its 1st production run of .300 and .338 Norma Magnum casings with a major diameter of .580”, it was brought to Peterson’s attention that some customers would rather the major diameter of the Peterson .300 and .338 Norma Magnum casings be the same size as the .300 and .338 Norma Magnum casings produced by Norma. That diameter is .583”.

Peterson has received a lot of compliments on its first run of .300 and .338 Norma Magnum brass. Customers have stated that the Peterson casings hold more pressure, and that they can get more reloads. Several have said things, like this customer who enthused, “The Peterson Brass I’ve been testing in .300 Norma Mag is by far the best .300 Norma Mag brass I’ve used to date. The accuracy is outstanding.”

After studying the potential problems associated with changing its .300 and .338 Norma Magnum major diameter, Peterson decided to modify its tooling to change the major diameter of its .300 and .338 Norma Magnum casings to match Norma’s major diameter which is .583”. As a result, all future production runs of Peterson’s .300 and .338 Norma Magnum casings will have a major diameter of .583” to match the Norma Magnum casings produced by Norma.
 
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SheepShapeAK

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What was the date for the Peterson press release?
Not sure. I bought the brass off of Graf’s and that’s what they had posted at the bottom. Sure am glad I bought a bunch. They raised the price of the cases almost $100 since I bought them.
 

codyadams

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So after looking through some of the notes posted here for load data, this is the ladder test I’m going with.

If any of you see anything that looks off, please chime in.

Defiance Deviant Tactical action with a 26” Bartlein 5R 9.3 twist.

Peterson Brass (First Run .338 NM)
Primer - GM215M
Bullet - 275gn Badlands Bulldozer II
Powders - H1000 and IMR 7828 SSC

Going up in .5 grain increments.

H1000 - Start 83 grains / End 87.5 grains
IMR 7828 SSC - Start 80 grains / End 84.5 grains
From what I saw with the 270 SBD, and the SBDII being 5 grains heavier and a little different/more bearing surface, that is pretty much what I would do. You may end up being able to go up a little higher, but I bet you will be close, maybe not. If it is virgin brass, the first firing may soak up and hide a little pressure as well, so watch out for that. Excited to see how your "Moola" rifle shoots!! That rig is a looker for sure
 

SheepShapeAK

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From what I saw with the 270 SBD, and the SBDII being 5 grains heavier and a little different/more bearing surface, that is pretty much what I would do. You may end up being able to go up a little higher, but I bet you will be close, maybe not. If it is virgin brass, the first firing may soak up and hide a little pressure as well, so watch out for that. Excited to see how your "Moola" rifle shoots!! That rig is a looker for sure
It doesn’t need to be the fastest. Just trying to find a really nice hunting load and one I can use for pushing it out to the 1500 yard mark.

Hopefully the weather holds out next Friday and I can go shoot. My magazines would only let me run a COAL of 3.752”. I could have swore the CIP length mags were supposed to be 3.850”
 

WeiserBucks

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20210623_191332.jpg


You'll be fine with the 1st run Peterson brass. This is a piece of 1st run 300 Norma that I bashed for 16 firings over the course of a few days. The first 10 or so were tame, but in the name of science I stepped on the gas progressively. It took a serious beating, full length sized each time, never annealed, trimmed 5x. Primer pockets are still good and I'd use it without question.
 

SheepShapeAK

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View attachment 281199

You'll be fine with the 1st run Peterson brass. This is a piece of 1st run 300 Norma that I bashed for 16 firings over the course of a few days. The first 10 or so were tame, but in the name of science I stepped on the gas progressively. It took a serious beating, full length sized each time, never annealed, trimmed 5x. Primer pockets are still good and I'd use it without question.
Good to hear!

Watch out for that bear in your living room!!
 

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