300 Norma Mag

I have had very good luck with it I have a few posts in this thread with load data for it using RL26. My barrel was not chambered specifically for the flatline, I am actually jumping a long ways, need to look but its the most jump I have ever had. My die stays set the same for 230 smk at .015 jump and gets me exact OAL that Warner recommends 3.765" and shoots very well probably luck but worked out well.

Have not shot many flatlines as spotting was more than a challenge especially early this spring when it was wet. I could probably get a bullet splash now to kick up some dust but if it wasn't on steel first round it was a guess where it went most of the time.
Gawd I hate no trace, no splash shots. May as well take a bullet and throw it in the trash can lol. What brand barrel is shooting them well?
 
Having issues tuning my 300NM with 225 ELDMs , they want to be near the lands , but any closer than
0.010 sees the ES go silly . Any more jump than 0.025 and groups are poor . Best load was :
ES 4 SD 2.3
84.7 of H1000
0.015 jump
CCI 250
28 inch 8 tw Bartlein
Just under 0.5 MOA for 3 shots ( barrel life ! )

No 1 and 2 below are best load with 225 .

AFCEF32A-9AF5-4BAF-AF87-B79609708360.jpeg
Below is pic of 230 Hybrid load .

35CE10C3-950B-400A-A68F-28F6B92C7726.jpeg
 
Having issues tuning my 300NM with 225 ELDMs , they want to be near the lands , but any closer than
0.010 sees the ES go silly . Any more jump than 0.025 and groups are poor . Best load was :
ES 4 SD 2.3
84.7 of H1000
0.015 jump
CCI 250
28 inch 8 tw Bartlein
Just under 0.5 MOA for 3 shots ( barrel life ! )

No 1 and 2 below are best load with 225 .

View attachment 6924027 Below is pic of 230 Hybrid load .

View attachment 6924029

Looks like you found a winner with that Berger. I am just about to start load development with the 225s in my AXMC. Hopefully I have better luck then what you are seeing as I just bought 300 of them to give a go.
 
Having issues tuning my 300NM with 225 ELDMs , they want to be near the lands , but any closer than
0.010 sees the ES go silly . Any more jump than 0.025 and groups are poor . Best load was :
ES 4 SD 2.3
84.7 of H1000
0.015 jump
CCI 250
28 inch 8 tw Bartlein
Just under 0.5 MOA for 3 shots ( barrel life ! )

No 1 and 2 below are best load with 225 .

View attachment 6924027 Below is pic of 230 Hybrid load .

View attachment 6924029
Maybe they don't like the 8 twist? I thought I remembered reading that eld's didn't like upper end twist. I could be wrong.
 
Looks like you found a winner with that Berger. I am just about to start load development with the 225s in my AXMC. Hopefully I have better luck then what you are seeing as I just bought 300 of them to give a go.
I have an AXMC with the factory 300nm barrel, which is a 1:10 twist. It shoots lights out with the 225 eldm's. 84 gr of h1000 and .010 off the lands.
 
  • Like
Reactions: MOUNTIC
Maybe they don't like the 8 twist? I thought I remembered reading that eld's didn't like upper end twist. I could be wrong.

Yeah maybe . They’re not running crazy fast , around 2930 ish same as the 230’s . Berger bullets are
non - existent in Australia , so I’ll just have to run with the 225’s for now . I have a feeling they might like
a jam , but that’s a retune , and barrel life is too short to bother with that .
 
So is RL33 the go to powder for 300Nm? Retumbo? I’m about to start plotting on 230 loads.

R33 wasn't widely available when I had my norma so I ended up using AR2225/Retumbo. Had very good results, 84.5gr of Retumbo got me 2920fps (SD = 6) with the 230gr Berger hybrid target projectile out of a 28 inch 9 twist Bartlein. Unsure of what barrel life would be as the rifle is now sold, but I'd anticipate it would be slightly better than using AR2217/H-1000. I don't have enough experience to be confident in that statement though.
 
I've been working on developing a load for my .300NM, and this is what I've come up with:

- 230 Bergers 0.015" off the lands
- 84.4 grains of Retumbo
- Norma brass
- CCI 250 magnum primers

My barrel is a ~29" benchmark barrel, 1:8 twist. My final velocity is ~2923 fps, with an ES of 12. There were nodes higher, but I ran in to pressure pretty early.
 
I've been working on developing a load for my .300NM, and this is what I've come up with:

- 230 Bergers 0.015" off the lands
- 84.4 grains of Retumbo
- Norma brass
- CCI 250 magnum primers

My barrel is a ~29" benchmark barrel, 1:8 twist. My final velocity is ~2923 fps, with an ES of 12. There were nodes higher, but I ran in to pressure pretty early.
How many rounds so far..it might speed up more
 
I'm about to grab some Dies. Any advice? I never use really expensive dies and my ammo has always come out perfect. I use Forster Micrometer seater for 6.5 and love it. I was thinking about grabbing one of those. How about for sizing dies? I was thinking just RCBS? Should I get type S? What size bushing for peterson brass?
 
I'm about to grab some Dies. Any advice? I never use really expensive dies and my ammo has always come out perfect. I use Forster Micrometer seater for 6.5 and love it. I was thinking about grabbing one of those. How about for sizing dies? I was thinking just RCBS? Should I get type S? What size bushing for peterson brass?

I have the Redding and also the Hornady. S types. The Hornady sizes the body much too small and I would not recommend it. If I size it on the Redding and then right again on the Hornady, it is like I'm resizing fired brass again. Works the brass way to much for my liking. Redding for me. I have 336 neck bushing for my Peterson brass. Haven't used my 337 or 335 yet.
 
Last edited:
I have the RCBS and also the Hornady. S types. The Hornady sizes the body much too small and I would not recommend it. If I size it on the RCBS and then right again on the Hornady, it is like I'm resizing fired brass again. Works the brass way to much for my liking. RCBS for me. I have 336 neck bushing for my Peterson brass. Haven't used my 337 or 335 yet.
Good info thanks.
 
I have the RCBS and also the Hornady. S types. The Hornady sizes the body much too small and I would not recommend it. If I size it on the RCBS and then right again on the Hornady, it is like I'm resizing fired brass again. Works the brass way to much for my liking. RCBS for me. I have 336 neck bushing for my Peterson brass. Haven't used my 337 or 335 yet.
What shell holder are you using? Damn you would think that would be easy to figure out but there is conflicting info everywhere and I can't find anything definitive. Sounds like redding 35 will work but it is almost $15. I'm not super cheap but $15 for a shell holder??
 
Never tried a Whidden. What noticable differences are you seeing? Enough to do anything for you down range? Or just for piece of mind?. In my post I wrote RCBS but meant Redding. Was traveling and don't know why. Lack of sleep. But I see really good results with half inch 5 round groups on magnums when reloading with Redding dies. I have been using a full size Redding with 336 bushing and can't think of a reason to change . Don't know if I'll get better then that on factory AI and Cadex rifles.
 
Never tried a Whidden. What noticable differences are you seeing? Enough to do anything for you down range? Or just for piece of mind?. In my post I wrote RCBS but meant Redding. Was traveling and don't know why. Lack of sleep. But I see really good results with half inch 5 round groups on magnums when reloading with Redding dies. I have been using a full size Redding with 336 bushing and can't think of a reason to change . Don't know if I'll get better then that on factory AI and Cadex rifles.

I get a lot more shoulder bump variation using a Redding Type S FL sizer vs the Whidden FL bushing sizer. Mind you, my experience with this has been with 6.5 creedmoor, as I had FL sizers in this cartridge from both companies. Same press, same lube, same brass, same press technique - but more repeatable and precise results with the Whidden. It has caused me to move to Whidden for all my cartridges.

Shoulder bump variations will change the pressure and and thus velocities - an inconsistency in ES/SD will be seen. The greater the variation, the greater the inconsistency.

What's interesting, is that PRS precision rifle shooters seem to not like Whidden dies as they supposedly see more run out from them. I see this posted on PRS/precision rifle Facebook groups (ugh) and here. However, bench rest shooters, such as those on accurateshooter.com, swear by Whidden and think they are some of the best dies - this group of shooters is trying to achieve the goal of ultimate precision.

I've never measured run out, so I can't personally speak to that. What I can say though, is that my most accurate reloaded rounds to date have all been produced with Whidden dies. All of the cartridges I currently reload for have an ES of 15 or less (a lot more factors than just the dies for that, I know), and my smallest groups ever shot were produced by ammo reloaded with Whidden dies.

For me, I have seen a difference and have great success with Whidden dies. However, if something else is working for you, keep using it.
 
  • Like
Reactions: MOUNTIC
Bartlein 1/9-26”, Norma brass, 86gn. Retumbo, Hornady 225gn. Eld-m, gets me 2980fps.
I could go a bit higher, but I was looking for @ 3000fps. The 100 yd. groups are .5 moa.

I am totally happy with load, and I have a ton of Retumbo.
Out of curiosity, does anyone see pressure signs on hot days with RE33?
 
I'm getting so done with Retumbo. I had a killer recipe that's been great up until this summer. 86.5 grains in Norma brass with 225 eld-m's. CCI #250 primers. Velocity in the 3040 range with no signs of pressure. As summer has progressed, the load has been getting hotter though and yesterday I could hardly open my bolt. It was 84 yesterday with some humidity, but I didn't think it would climb that much. I'm also done with Norma brass. I just prepped 250 rounds of Peterson brass and I'm starting load work up all over with Reloader 33. I'll post progress later.
 
I couldn't get retumbo and 225eldm to shoot at all for me. I switched to h1000 and it was night and day difference. Now I'm trying 215 berger's with h1000 but so far the groups are not good.
 
Bartlein 1/9-26”, Norma brass, 86gn. Retumbo, Hornady 225gn. Eld-m, gets me 2980fps.
I could go a bit higher, but I was looking for @ 3000fps. The 100 yd. groups are .5 moa.

I am totally happy with load, and I have a ton of Retumbo.
Out of curiosity, does anyone see pressure signs on hot days with RE33?

I'm not having any pressure issues with my load. I believe I originally developed the load in the summer. I run 92.6grs of RE33 under a 230gr Berger Hybrid, CCI #250 primer, Norma brass.

I use a .5fps modifier in AB for temp adjustment. It seems spot on.
 
Starting to order components now while my barrel is getting spun up. Going to use the 230 hybrids but reading through the thread it seems like people have switched from H1000 to re33. Is this the consensus now for the 230 hybrids for what I should order?
 
Starting to order components now while my barrel is getting spun up. Going to use the 230 hybrids but reading through the thread it seems like people have switched from H1000 to re33. Is this the consensus now for the 230 hybrids for what I should order?

I'm pretty much sold on RE33. I used H1000 and Retumbo when I initially got the rifle, RE33 gave me better velocity. I was able to develop accurate loads for all 3. But I also use this rifle for hunting, and my velocities stayed very solid all through the fall and winter. I think I shot my elk the last weekend of October. And we had some long range fun several times through the winter without issue. So temp stability is pretty good.

I've also been tinkering with the 225gr ELD-M, and I'm liking what I see there. Slightly better BC than the 230gr Berger and it moves a hair faster (21fps). I may make the switch.
 
  • Like
Reactions: MACHTECH
I'm pretty much sold on RE33. I used H1000 and Retumbo when I initially got the rifle, RE33 gave me better velocity. I was able to develop accurate loads for all 3. But I also use this rifle for hunting, and my velocities stayed very solid all through the fall and winter. I think I shot my elk the last weekend of October. And we had some long range fun several times through the winter without issue. So temp stability is pretty good.

I've also been tinkering with the 225gr ELD-M, and I'm liking what I see there. Slightly better BC than the 230gr Berger and it moves a hair faster (21fps). I may make the switch.
What barrel twist are you running?
 
I'm at the range now letting my barrel cool. It's hot and humid again today and the RL33 is looking much better. I started at 90 grains and went up to 94 by 1gr. increments. Primers just started to flatten out at 93gr. Still no ejector marks. Great accuracy at 92 and 93. Haven't put the magnetospeed on yet. Just trying to check pressure and find a node.
 
Cheaper too.

Haha, yeh... And that never hurts anyone's feelings..

I'm at the range now letting my barrel cool. It's hot and humid again today and the RL33 is looking much better. I started at 90 grains and went up to 94 by 1gr. increments. Primers just started to flatten out at 93gr. Still no ejector marks. Great accuracy at 92 and 93. Haven't put the magnetospeed on yet. Just trying to check pressure and find a node.

That pretty much matches my experience. I think I loaded to 93.6, it was showing some pressure there. Pretty flattened out primers, but I don't think bolt lift was heavy. I believe 93.2 was the top end of the recommended charge weight per Berger. In .2 increments I definitely have a very nice flat spot at 92.4/92.6/92.8. So I loaded in the middle at 92.6 and I get nice single digit deviations. The groups I have shot have all been under .5. Though admittedly, I don't shoot many groups with this rifle. Three shots to confirm zero then playtime at 1000 yards plus. Even 1200 yards feels like a waste of ammo sometimes.
 
Haha, yeh... And that never hurts anyone's feelings..



That pretty much matches my experience. I think I loaded to 93.6, it was showing some pressure there. Pretty flattened out primers, but I don't think bolt lift was heavy. I believe 93.2 was the top end of the recommended charge weight per Berger. In .2 increments I definitely have a very nice flat spot at 92.4/92.6/92.8. So I loaded in the middle at 92.6 and I get nice single digit deviations. The groups I have shot have all been under .5. Though admittedly, I don't shoot many groups with this rifle. Three shots to confirm zero then playtime at 1000 yards plus. Even 1200 yards feels like a waste of ammo sometimes.
Is this a standard 300 norma. Not a improved
 
Its way off for me. I'm pushing 2940 with 83.6 GR of Retumbo and a 230 Berger Hybrid. I get stuck cases, hard bolt lift and a bunch of other pressure problems if I go north of 85 grains. Accuracy is good, so far around 1/2 moa out to 600 yards. This is with Norma brass which only seems to last me 3 loadings max before its smoked. I just got 100 cases of Peterson in the mail today which I'm going to do a whole new workup on with RE33.
 
  • Like
Reactions: jonthomps
It's way too hot for me as well. I'd like to know what reamer the Berger guys were using to determine these numbers. I'm at 86gr of RE33 with a 215 moving at 3120fps from a 27" Bartlein barrel. 94 grains?!? I'd blow my gun up.
 
Is this a standard 300 norma. Not a improved

Yes, It's a standard Norma.

And I haven't seen that chart above on RE33 before. I could have sworn I saw a spreadsheet from Berger saying 93.2 was max recommended load using the 230gr Hybrid. Which seems more realistic. I think a person can push to 94grs with some rifles, I think mine could get there, but it would be smoking hot. 94.7grs is crazy. No idea how they are doing that.

And the velocity is off. I'm 130fps faster than their numbers using 1.1grs less powder. Same length 26" barrel. I can only speculate that their 10" twist rate allowed them to work up with a hair less pressure. Doesn't really explain the lower velocities though. My initial work up on the new rifle had a nice node at 2980fps (92.4grs RE33). After 150 rounds I worked up a new load that had a node that was only .2grs higher at 3050fps.
 
Just did some experimenting with Reloader 33 this morning. 90 grains got me 3012 avg with a 230 Berger. I maxed out with pressure at 93 grains and almost 3100 FPS. 1x Norma brass, 28” bartlein 9 twist. So far the powder seems promising. Prior to this I was only getting 2920-2940 ish with H1000 before major pressure, same with Retumbo.
 
  • Like
Reactions: BullzeyeNJ