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300 Norma Mag

So here are my last two results with the 198 Flatlines and N570.

The target with 6 different groups (5 are from the .300 NM, the one on the very bottom left is from one of my 7 WSMs) is the most recent and was testing seating depths. All my previous shooting was done with the projectiles touching the lands. The rifle/projectiles seem to prefer .005 jump better for accuracy than touching and definitely didn't seem to like jumping .020 or .050 jump. This wasn't much of a surprise since they are so long. These groups were shot at 100 yards and the best was the CCB with .005 jump and measured 2/3 MOA.

No, they aren't 5-shot groups with the cost to shoot these things, plus barrel life; I'm not keen on wasting them.

The other target with one group was shot at 300 yards. It was 6x 3-shot groups with varying powder charges, and the projos were set to touching. It managed about 1.1 MOA.

I only have about 70 rounds through this barrel but 1 MOA seems to be about where I'm at with it or a little better. I'm also not pushing these projectiles as fast as I could but I'm not trying to kill the brass within 2 firings either.

By the way, I have an unopened 8-pound jug of Retumbo if anyone has some N570 to trade around Texas.
 

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You might try tighter neck tension. I was getting similar results with solids in my .300NM but when I swapped the bushing and mandrel for tighter necks I got much better groups. Of course, your mileage may vary.
 
There are a few things I have in mind to try and thanks for the suggestion. I'll get there in due time.
 
Need help loading ELR 300 NM with new long projectiles. Would like to increase throat out to 3.780” OGIVE to use new long projectiles 245 Elite Hunter and 250 ATIP. Then I could then seat my new projectiles within the mag or hand feed and not be forced to seat below dreaded Neck Shoulder Junction. My local gunsmith will not do it and will go to OGIVE max 3.766” - will not explain why…please give me some insight or thoughts. Am I going wrong or too far?
 
Need help loading ELR 300 NM with new long projectiles. Would like to increase throat out to 3.780” OGIVE to use new long projectiles 245 Elite Hunter and 250 ATIP. Then I could then seat my new projectiles within the mag or hand feed and not be forced to seat below dreaded Neck Shoulder Junction. My local gunsmith will not do it and will go to OGIVE max 3.766” - will not explain why…please give me some insight or thoughts. Am I going wrong or too far?
I'm not an expert but I think you need to have a different Reimer to get the longer throat
 
Sorry for the crap post. But for some reason I can’t view the entire thread without posting.
 
Here's the data I collected so far - new Lapua brass out of a MRAD (26" 1:8 twist rate as I recall) - likely switching to a preferred powder as well - but run what you got was the idea here:

H50BMG (91gr was getting crunchy during bullet seating)
220gr SMK
86gr - 2717fps - 8.29sd
87gr - 2771fps - 10.1sd
89gr - 2838fps - 6.05sd
90gr - 2877fps - 2.76sd
91gr - 2900fps - 7.35sd

H50BMG
230gr A-Tip
91gr - 2833fps - 3.30sd

H4381
220gr SMK
77gr - 2916fps - 2.62sd
78gr - 2979fps - 13.3sd
79gr - 3016fps - 4.5sd
80gr - 3035fps - 10.3sd

H4381
230gr A-Tip
74gr - 2690fps - 16sd
---skipped 75,76gr---
77gr - 2779fps - 9.93sd
78gr - 2814fps - 5.1sd
79gr - 2859fps - 11sd
80gr - 2898fps - 6.02sd
81gr - 2950ps - 10.1sd

H4350
230gr A-Tip
77gr - 2949ps - 6.6sd
 
Here's the data I collected so far - new Lapua brass out of a MRAD (26" 1:8 twist rate as I recall) - likely switching to a preferred powder as well - but run what you got was the idea here:

H50BMG (91gr was getting crunchy during bullet seating)
220gr SMK
86gr - 2717fps - 8.29sd
87gr - 2771fps - 10.1sd
89gr - 2838fps - 6.05sd
90gr - 2877fps - 2.76sd
91gr - 2900fps - 7.35sd

H50BMG
230gr A-Tip
91gr - 2833fps - 3.30sd

H4381
220gr SMK
77gr - 2916fps - 2.62sd
78gr - 2979fps - 13.3sd
79gr - 3016fps - 4.5sd
80gr - 3035fps - 10.3sd

H4381
230gr A-Tip
74gr - 2690fps - 16sd
---skipped 75,76gr---
77gr - 2779fps - 9.93sd
78gr - 2814fps - 5.1sd
79gr - 2859fps - 11sd
80gr - 2898fps - 6.02sd
81gr - 2950ps - 10.1sd

H4350
230gr A-Tip
77gr - 2949ps - 6.6sd
Thanks for sharing !

Just 2 points:

1. When you say H4381, do you mean H4831 or H4831SC?

2. I’m surprised by how good H4350 was! I would’ve thought that was waaay too fast of a powder to be used! Well done!

I’m going to start my load development next weekend. Going to be loading up some 225 ELD-M with H1000 and N570 to see results.

I’ll report back when done
 
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Thanks for sharing !

Just 2 points:

1. When you say H4381, do you mean H4831 or H4831SC?

2. I’m surprised by how good H4350 was! I would’ve thought that was waaay too fast of a powder to be used! Well done!

I’m going to start my load development next weekend. Going to be loading up some 225 ELD-M with H1000 and N570 to see results.

I’ll report back when done
H4381 (not SC) and I wouldn’t have tried the 4350 but Nosler said it was the most accurate (IMR 4350 specifically) for the 300RUM which is pretty similar
 
I have just about everything for 300NM except for a chambered barrel. Any preferred gunsmith that can do one on a AXMC?
 
Here's the data I collected so far - new Lapua brass out of a MRAD (26" 1:8 twist rate as I recall) - likely switching to a preferred powder as well - but run what you got was the idea here:

H4350
230gr A-Tip
77gr - 2949ps - 6.6sd

Does anyone have a suggestion for where to start from this number (77gr) for a 220gr SMK? I have quite a bit of H4350, but don‘t want to blow myself up! I will am shooting a 26” Proof Research carbon fiber barrel on an AXSR.
 
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Never heard of anyone using H4350 in a .300NM, but here's the data for the 220SMK
 
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Does anyone have a suggestion for where to start from this number (77gr) for a 220gr SMK? I have quite a bit of H4350, but don‘t want to blow myself up! I will am shooting a 26” Proof Research carbon fiber barrel on an AXSR.
You're just burning up the barrel with that powder. You should be running that 220 around 3100 fps at max pressure with the right powder. Why bother for 300 WSM ballistics?
 
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You have convinced me. Only considered it based on the numbers the user posted above. He quotes 300 ft/sec faster (10gr heavier) than the calculated data.

edit: Here is what scares the crap out on me. Above says 96.1gr Ramshot LRT (2903 ft/s), where another reference says max load is 89.6gr (2929ft/s).
 

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You have convinced me. Only considered it based on the numbers the user posted above. He quotes 300 ft/sec faster (10gr heavier) than the calculated data.

edit: Here is what scares the crap out on me. Above says 96.1gr Ramshot LRT (2903 ft/s), where another reference says max load is 89.6gr (2929ft/s).

Right. Look at the overall cartridge length.
 
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I’m having Bartlein spin me up a 30” 300NM barrel for my AXMC with the plan of using Lapua brass and Berger 245s. Is there a preference for powder? Retumbo and h1000 I assume, but is one better then the other?
 
N570 is nearly perfect for .300NM across a variety of bullets and will give you a bit more velocity than H1000 and Retumbo, in that order. RL33 is also a good option for the heavier bullets, but it's just a tad on the slow side.
 
N570 is nearly perfect for .300NM across a variety of bullets and will give you a bit more velocity than H1000 and Retumbo, in that order. RL33 is also a good option for the heavier bullets, but it's just a tad on the slow side.
I've had great results with RL33 and 230's. Pushing 3050 with 91.5 gr
 
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BECAUSE, it's not a 300 PRC, it was developed before it, BECAUSE, the Lapua case was shortened to the 338 Norma to accommodate longer bullets to fit in the magazines at the time, AND shortly after it was realized that the .30 caliber bullets had higher bc's and less recoil, giving up very little to the 338's at long range.
 
Wondering if anyone has loaded the badlands precision super bulldozer 2 in their norma? I have h1000, retumbo, or vv n570
 
Can someone please measure a loaded Lapua brass round case neck diameter please? I need to order some bushings.
 
Newby here. Just built my 300 Norma
Mausingfield action
Proof barrel 26”
Ag composite stock
Triggertech diamond
Lr customs brake

Been looking for retumbo or h1000 and I might as well be looking for a unicorn. I can get my hands on h50bmg and US869. I know both have a slower burn rate than the retumbo or h1000. My question is where to start for load development. Gonna be using 230gr A-tips. What kind of velocities can I or should I semi expect out of those powders?
 
I know it's not on your list of powders, but another option if you can't find those powders is RL33. I'm getting 3050 fps out of a 27" barrel with single digit sd's.
 
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I know it's not on your list of powders, but another option if you can't find those powders is RL33. I'm getting 3050 fps out of a 27" barrel with single digit sd's.
That’s a hard one to find also. I have on hand 6lbs hybrid100v, 5lbs 4831sc, 1 1/2 lbs reloader 23, 1/4lb h1000, and tons of small caliber and pistol powder which does me no good.
 
1660062943435.png

Here are some powder options for you, but as you know the best fits are hard to find.

Ramshot LRT is easy to find and would be a better choice than H50BMG and US869. It's still slow though.
 
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Here are some powder options for you, but as you know the best fits are hard to find.

Ramshot LRT is easy to find and would be a better choice than H50BMG and US869. It's still slow though.
Was just at store and they had ramshot magnum and accurate magpro. Ever tried them? Pros? Cons? You can see?
 
No, I've been using primarily N570, though have also used N565 and RL33. Both Magpro and Magnum should work in .300NM; a little on the fast side but better than LRT, in my opinion.
 
I know it's not on your list of powders, but another option if you can't find those powders is RL33. I'm getting 3050 fps out of a 27" barrel with single digit sd's.
Are you finding R33 to be dirty? I’m reading of people having to clean every 30-40 rounds.
 
It’s no more dirty than N570, but I wouldn’t say it’s so dirty that you have to clean that often.
 
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It’s no more dirty than N570, but I wouldn’t say it’s so dirty that you have to clean that often.
Currently I can’t really find any powder that’s high on the list for 300NM. I found a local guy who has some 33 for sale so I’m trying to see if/how well that would work.