300 Norma Mag

[Reload10]

^^ thanks for the info.

Isn't that super hot for a non improved with a 220gr??

 

[Dogtown]

Something is wrong with VV's data for .300NM as far as I can tell. Take a look at my post further up the page with charts.

 

[Dogtown]

I loaded a range from 89.6gr to 94.4 @ 3.585" COAL with N570 and only saw obvious pressure signs starting around 93.8gr. There was a gradual flattening of primers in the second half of charge weights, but nothing excessive and no cratering or sticky bolt.

 

[Globalstar66]

I called Berger today and spoke with Cory. He had no idea that VV's data was 15gr less powder than Berger's data, both using 230gr Hybrid Target bullet. He said the Berger data was taken from QL and that VV actually shot theirs, but the VV data makes absolutely NO sense. With VV's starting load of only 71gr (using 230gr bullet), pressure is only like 30000 psi or so, vs max pressure of almost 64000 psi according to QL. I cannot believe VV would actually publish such extremely LOW powder charges.... I mean 15gr LESS than Berger data is huge - all things being equal with 230gr Berger bullet and N570 powder.

 

[Globalstar66]

Received a follow-up email from Bob at Berger Bullets today, explaining the massive difference in powder charges between VV's data and Berger's data. Makes sense - somehow I never saw the COAL the 2 use... Here's his email: "We do have unpublished Berger Load Data available for use with you .300 Norma Magnum using our 215 grain, 230 grain, and 245 grain weight bullets. The differences in our Berger Load Data and the Vihtavuori Load data is simple to explain and the differences are controlled by the COAL used in the Berger Load Data which is for 3.680" COAL and in the Vihtavuori Load Data which is for a 3.406" COAL. That is a difference of 0.274" inches in the COAL length and this does make for this difference in internal case volume that can be worked with with the respective load data from either team. This shows that our Berger Load Data team here in the US and our Vihtavuori Load Data team do work independently of each other. This is due to the fact that our team in Vihtavuori, Finland must work with the CIP dimensions under penalty of law and we work under the auspices of the SAAMI industry standard here in the US."

 

[moaflat]

Wasn't going to post this...but since you asked...

This is my 8 twist 28" 300NM shooting 250gr A-Tips with R33. I am steering clear but you might have better luck.

View attachment 7147620

Thank you Yerman for the 250 ATips info...well documented and always love the 3 guys graphic. Couple of questions:
> stopped abruptly at 89.5gr R33 with 250AT because hit pressure or was that last round? And have you tried Berger 245's or 230 ATs to compare with 8:1T?
Thanks in advance for excellent support provided - great work! So far Hornady 225 ELDMs, 230 SMKs 92.2gr R33 (3050) 32" 8:1T BR2 (each rifle barrel is custom and overall machined uniquely different from one to another, safety emphasis on each barrel must be slowly stepped up to this max load using .2gr increments) excellent results on last 4 builds 300NMs sub. ¼" or better. Now working on single feed 300NM 32" Bernard Action 8:1 carbon wrap custom reamed for 250 ATIP.

 

[Dogtown]

I finalized a load using Berger 220s with N570:

Berger 220 Hybrid Long Range
Lapua Brass
Fed GM215M
92.6gr N570
3.585" COAL
Neck expanded to 0.3055"
3265fps AVG out of 28" barrel

This is after first trying RL33 pressure testing and getting really wild variation over linear powder increments. The switch to N570 significantly smoothed out the velocity curve and gave me a good bracket of safe pressures to work with.

• ran 3-shot strings of 90.0 - 94.0gr (+/- 0.2) to look for velocity node
• ran 5-shot strings of 92.2 - 92.8gr (+/- 0.1) to narrow the search for velocity consistency.
• ran 5-shot strings of 92.6gr (+/- 0.002") with seating depth variations
• ran 5-shot strings of 92.6gr @ 3.585" (+/- 0.0005") with neck tension variation

The last step all had acceptable groups, but one real standout winner (low single digit SD and very tight group). I'm going to do a practical test this weekend and hopefully bang steel for the first time this year.

Overall, the velocity is impressive and I worried that I was running it hot, but I didn't see pressure signs until 93.2gr. From there to 94.0 I started seeing flattening of primers, then cratering and light ejector marks, so I made 93.0gr the powder ceiling. I traditionally use seating depth tests to finalize a load, but doing neck tension tests as well is a new extra step for me and if anyone sees holes in my process, please let me know.

 

[Reload10]

^^ very nice. Standard or improved nm?

 

[Dogtown]

Standard.

 

[Shawnsts]

I am running out of retumbo but have a bunch of N570. I am wondering if anyone has ran n570 with 225 eldms? Retumbo was amazing but those days are almost over. Trying to figure out if n570 will work and a starting point.

I was running 225eldm, 86.5gr retumbo @ 3050fps.

 

[Dogtown]

Give it a try and you can see above that it's working really well with Berger 220s.

 

[Shawnsts]

Dogtown, I didn't catch that you were using 220s, I will try that. I never went hot enough with retumbo to find pressure signs. I guess I will start @ 85gr and work my way up. 92gr of N570 seems like a lot and your speeds are smoking.

 

[Dogtown]

Yup, I'm still a bit puzzled by the velocity being higher than expected, but I wasn't seeing pressure signs so I'll take it. As you may have read further up there's concern that Vihtavuori's data is off, so I interpolated data from a variety of sources with similar bullets. 85gr should be a good starting point, especially if you're seating to a more standard 3.680" COAL (mine prefers 3.585").

 

[mindekei]

My update:
DT SRS with Proof carbon 28" 1-8T barrel.
Custom freebore to fit standard 338LM Magazine
250 A-tip
Lapua case
215M
VV N570
Jumped 0.025 from JAM

COAL 3.7095"
CBTO 2.8455"

Powder charge test #1
Soon will do more detailed powder charge weight test in 84-85 area (MV and POI based) also here it was very cold, so would like to get same winter/summer load if possible.

Shots #9-10 already were showing quite visible ejector marks, but no swings still. Primers were OK.

 

[jeffmedlin]

My update:
DT SRS with Proof carbon 28" 1-8T barrel.
Custom freebore to fit standard 338LM Magazine
250 A-tip
Lapua case
215M
VV N570
Jumped 0.025 from JAM

COAL 3.7095"
CBTO 2.8455"

Powder charge test #1
Soon will do more detailed powder charge weight test in 84-85 area (MV and POI based) also here it was very cold, so would like to get same winter/summer load if possible.

Shots #9-10 already were showing quite visible ejector marks, but no swings still. Primers were OK.

I saw in an earlier post, you were asking about freebore length. I am curious what freebore you went with? Did you have a custom reamer made? Or did you move it back with a uni throater?

 

[mindekei]

I saw in an earlier post, you were asking about freebore length. I am curious what freebore you went with? Did you have a custom reamer made? Or did you move it back with a uni throater?

Sent bullet, case and mag to a smith and he adjusted freebore as per my requirements. I know its silly but right now I dont have measurement. it supposed to be 0.020" jump when bullet is seated @ case neck - shoulder junction, but not longer than MAG lenght.

 

[Nomad_chew]

Been trying to find powder for my 300NM and its been pretty hard and it’s getting even harder now.
I would love to use Retumbo, H1000, N570, or RL33 but haven’t turned up anything. Today I snagged 5lbs of RL25 and 1000 215GM primers so I’m pretty happy. Anyone used RL25? I have found very little of others using it.
Looks like it will only be 93% case capacity and from what I read not to temp stable. Anything good or bad I should also know about? Or other powders to be on the look out for.

26” 1:9 barrel
230 Berger and Norma Brass

 

[Dogtown]

It's a bit on the fast side for what you're shooting, but it'll work - you just won't get as much velocity as you'd get with slower powders. Ramshot/Accurate LRT has been more widely available, but is a bit on a slow side for this cartridge. Again, you can use both, but they're not ideal.

 

[912173]

I just shot a 15 round ladder of 250gr Atip / H1000 out of my 300 Norma. This was with once fired Lapua brass and federal 215M primers.

26" Bartlein 1:9" with chamber set to jump factory Berger 230 ammo (COAL 3.557", Ogive 2.655") .020" to the rifling.

At 125 rounds I measured .041" jump (.021" erosion?) and loaded the 250s at COAL 3.700". This OAL put the ogive at 2.690" from the case head and resulted in .005"-.006" jump to the rifling.

1/2 grain increments, 1 shot each, 62F, DA 5800, Alt 4400, Humidity 28%, tested with magnetospeed.

77.5 - 2732
78.0 - 2751
78.5 - 2750
79.0 - 2798
79.5 - 2812
80.0 - 2841
80.5 - 2860
81.0 - 2869
81.5 - 2893
82.0 - 2897 probably will test more here
82.5 - 2901
83.0 - 2923
83.5 - 2938 slightly heavier bolt lift?
84.0 - 2959 stiffness on bolt lift, slight ejector mark.
84.5 - 2986 noticeable stiff bolt and ejector mark. Stopped.

Sure would be nice if Hornady would put some Norma data up for their cool new bullets. I had to crunch numbers between 300 prc, 300 rum and other calibers to get a starting point. Hopefully this is useful for someone as there's not much out there.

 

[JB.IC]

Question for a potential build. (standard 300nm unless someone can convince me to go improved).

The powders I have on hand in large quantities: IMR 8133 and VV n565. Would any of these be good for 220 to 250 class bullets?

 

[WeiserBucks]

VV570 works great, I'd bet that 565 would work very well but I haven't used it personally.

 

[BClrh]

If you are in the heavy end of that range would use N570. N565 would be better in the lower end of those bullet weights or even lighter. N570 is an excellent powder that is pretty temp stable and gives max velocity but you will pay with barrel life.

 

[tyfoon]

Would anyone have a recommendation for a min-max load for 300NM with VV N565, Lapua brass and Hornady ELD-M 225gr? Will be shooting these in an Accuracy International AXMC with 28" Bartlein barrel.

The VV loads (with the very strange small COL) confuse me and I did not see any postings yet on N565.

Was maybe thinking between 82-94gr N565 for standard COL of 3.680"?

 

[Dogtown]

84gr looks to be a bit on the hot side for a starting load.

You might want to start closer to 77gr.

NOTE: if you read further up you'll see a discussion about how VV's load data for .300NM seems to be off.

 

[tyfoon]

84gr looks to be a bit on the hot side for a starting load. You might want to start closer to 77gr.

NOTE: if you read further up you'll see a discussion about how VV's load data for .300NM seems to be off.

Excellent! Thanks

I also have send VV a mail about their recommended load. Will report back if they come back to me.

 

[tyfoon]

Bit of a noob question here;

As I don't have access to long range ranges close, I actually will be shooting real ELR only a few times a year (and there is plenty of info in this and other threats that have appropriate loads for long range). However still In want to shoot the 300NM now and then but will be shooting at 100 & 300 meters. For those ranges there is no need to push the limits.....

What has the most positive impact in barrel life? Using light bullets or light loads? Any suggestions for load combinations for these short ranges that maximise barrel life would be appreciated.

 

[Dogtown]

Heat plays a big factor in throat erosion, so hotter loads theoretically will reduce your barrel life. However, some cartridges are more overbore than others, so they are going to erode the throat faster than less overbore cartridges, and .300NM is a bit more of the former (though not overbore like a .243Win). I don't think shooting lighter bullets will help prolong barrel life the way shooting lighter loads might, but then again what's the point? You have to start thinking about barrels as consumables, something that you will wear out and replace down the road, the frequency of which depends almost entirely on how often you shoot it.

In your situation, I'd use those shorter ranges for developing a good load for your .300NM, then enjoy it when you can stretch its legs a few times a year. And when you can't, shoot a short-action cartridge like a 6.5 variant? You've got an AXMC, so just swap the barrel and bolt face and be done.

Edit to add: also, understand that in many cases a worn out throat can be remedied by re-cutting the chamber and setting the barrel back an inch or so.

 

[tyfoon]

Thanks. Good input. What I'm reading is that there is no load combi that will significantly extend barrel life. If that indeed is the case I better just use the time on the short range with the 300nm to develop loads for the long range.

I also have a 6.5 creedmoor and a .308 barrel so will use these mainly on the shorter ranges.

 

[Dogtown]

Yes, exactly.

 

[Front_Royalty]

I just shot a 15 round ladder of 250gr Atip / H1000 out of my 300 Norma. This was with once fired Lapua brass and federal 215M primers.

26" Bartlein 1:9" with chamber set to jump factory Berger 230 ammo (COAL 3.557", Ogive 2.655") .020" to the rifling.

At 125 rounds I measured .041" jump (.021" erosion?) and loaded the 250s at COAL 3.700". This OAL put the ogive at 2.690" from the case head and resulted in .005"-.006" jump to the rifling.

1/2 grain increments, 1 shot each, 62F, DA 5800, Alt 4400, Humidity 28%, tested with magnetospeed.

77.5 - 2732
78.0 - 2751
78.5 - 2750
79.0 - 2798
79.5 - 2812
80.0 - 2841
80.5 - 2860
81.0 - 2869
81.5 - 2893
82.0 - 2897 probably will test more here
82.5 - 2901
83.0 - 2923
83.5 - 2938 slightly heavier bolt lift?
84.0 - 2959 stiffness on bolt lift, slight ejector mark.
84.5 - 2986 noticeable stiff bolt and ejector mark. Stopped.

Sure would be nice if Hornady would put some Norma data up for their cool new bullets. I had to crunch numbers between 300 prc, 300 rum and other calibers to get a starting point. Hopefully this is useful for someone as there's not much out there.

Extremely helpful! Been looking for exactly this data for my 8 twist. Now I have a starting point. Have you made any more progress in your testing? 2900 fps with a 250 sure is hummin. Have heard from 1 other that the ATIP likes the same jump as an ELDM: .015-.020". Seems yours may be in the same boat?

 

[joseph-98]

Took my 300 norma out today ... tried a group test... did not go so well, i started at 83 gr and worked up to 86.5 and the speeds were awesome but groups were pretty crappy... so I figure ill work a few more out and see if I can get it better......

 

[912173]

Second 250gr ATip test:
15 rounds 82.0gr H1000, once fired Lapua brass, Ogive 2.690", C.O.A.L 3.700", Fed 215M, .005" jump

57F, DA5600, Humidity 35%, Alt 4644'

26" Bartlein 9" twist with ultra 9 suppressor. My earlier ladder test was unsuppressed to check bullet stability with the 9" twist rate.

2891
2843
2876
2853
2851
2835
2873
2874
2870
2874
2869
2891
2873
2871
2871

I put 3 rounds on steel at 1030 yds with 6.4 mils elevation. It was within my last 3-4 shots (2891-2871fps) which did seem consistent on the plate.

AVG 2867
SD 15.8
ES 56

I think these bullets would like more jump but .005" is where I just ended up trying keep the bullet out of the powder and still jumping. I jump Berger 230s .020" with H1000 and it gets single digits SD routinely. I'll probably wait to experiment further until I can actually buy more H1000.

 

[dgheriani]

I finally got my .300 NM out yesterday to start load dev. 29.5" MTU/Heavy Varmint hybrid Krieger 9tw on a Stiller Tac338 in an MDT ESS with a Bushy XRS2.

Berger 220 LRHT, virgin Lapua cases, Fed 210M, Viht N570, OAL (bto) 2.820", COAL 3.623"
40F/462ft

1st 23rds

8 rds @ 90.0gr: 3098fps
3rds @ 90.5gr: 3144
3rds @ 91.0gr: 3156
3rds @ 91.5gr: 3162
3rds @ 92.0gr: 3177
3rds @ 92.5gr: 3183 bit of swipe, primers starting to flatten

Best group was at 91.0 (0.22moa) and best ES/SD was at 90.5 (8/3.9) and still decent accuracy (0.51moa) so gonna explore in 0.3gr increments between 90.4 and 91.0. Also gonna build a modified case gauge with a spent case to figure out where I am relative to the lands, I just used the OAL my smith suggested.

I was honestly quite surprised at how soft shooting it was, granted the rifle weighs 21lbs (with scope, bipod, mag) and has a 5-port Insite Heathen brake but it doesn't seem to recoil more than my similarly setup .308 (that has a 3-port Heathen). Less felt recoil/disturbed sight picture than my 14lbs 7Saum.

As an aside, as much as I love shooting the rifle, I hate reloading for it. N570 is a fucking nightmare. Clogged up my auto-thrower (gen 2)so I manually throw charges on my old Hornady powder thrower which still gets clogged, (though not as bad and easier to un-clog without making a huge mess) and finish on the auto-trickler. Any tips or better setups/better practices for dealing with the mini tree trunks that N570 is?

 

[Tchitcherine]

N570 flows without problem in my Chargemaster.

 

[Dogtown]

N570 has been a bit of a pain in the Autotrickler v3. It doesn't have a problem every throw, but quite a bit more than similar powders like RL33. There's not a whole lot you can do about that either, so when it gets to the point where I get a bit frustrated, I use Lee scoops to throw instead.

 

[Simia Dei]

Is anyone running the 245s in a long barrel? Have a 30" 9T barrel coming and have a lot of H1000 and Retumbo in the shed. I'm wondering if anyone has also tried Ramshot Magnum or IMR 8133? (N570 is no longer available here).

 

[dgheriani]

N570 has been a bit of a pain in the Autotrickler v3. It doesn't have a problem every throw, but quite a bit more than similar powders like RL33. There's not a whole lot you can do about that either, so when it gets to the point where I get a bit frustrated, I use Lee scoops to throw instead.

Yeah, I think I'll dig up some Lee scoops, will save me time and headache. I can't really be bothered to buy a charge master just to throw N570, haha. What decapping die do guys use for .300 NM? My cheap Lee is too small for the case.

 

[Bigrederic]

Well with like 40 rounds through my rifle... we started load development. It is a 1-9 28" M24 barrel...

After a 10 shot ladder, I settled on 88.9gr of IMR 8133 in Lapua brass with a GM215 primer and pushing a 225 ELDM at 3037fps. No heavy bolt lift, flat primers or anything beyond a very very slight shadow of a ejector mark.. It has single digit SDs and shot a few great groups under .5"

 

[Dogtown]

What decapping die do guys use for .300 NM? My cheap Lee is too small for the case.

I recently switched to a turret press (why did I wait 20 years?) and had to pick up some more decapping dies. Yes, the Lee ones are very inexpensive, but too small for those magnum cases. I picked up RCBS and Redding decappers and while the Redding was more expensive, I kind of like the RCBS better.

 

[dgheriani]

I've settled on a load for now, will see what happens once the barrel speeds up and with once fired brass.

Started on a clean barrel, interestingly there was not the usual slower 1st round I usually experience in different calibers and barrels.

Tested 10 rounds (2x 3rd groups, 1x 4rd group) at 90.4
avg: 3147
ES: 23.0
SD: 7.0

6 rounds (2x 3rd groups) at 90.7
avg: 3178
ES: 34
SD: 12.4

6 rounds (2x 3rd groups) at 91.0
avg: 3194
ES: 12
SD: 5.1

90.4 gave me the best accuracy and the numbers are acceptable to me given the barrel has 45 rds on it and this is with virgin brass. I'll take it out to distance now and then recheck accuracy and speed around the 75 or 100 rd mark.

 

[dgheriani]

Verified dope at 830, 940, 1497 & 1600 yards today. Either my barrel is still speeding up (which is possible as it's only at 65 rds after today) or the AB custom curve is slightly off but I was 0.2-0.3 high at 1600. Consistent hits at 1600 (24" plate) once I sorted that out. Unlike with my 6s and 6.5s, there's really no question that you hit the plate at that distance with the .300NM!I'll have recheck zero/accuracy and speed tomorrow. I didn't have my Labradar with me as it was a 1.8km uphill snowshoe/hike in, haha.

 

[Runnineh]

My barrel didn't get consistent until about 240 rounds.

 

[dgheriani]

My barrel didn't get consistent until about 240 rounds.

Interesting. Most guys I've talked to said things stabilized more around the 75-100 round mark. Most of my short action calibers stabilize around 150 or so.

 

[Runnineh]

Interesting. Most guys I've talked to said things stabilized more around the 75-100 round mark. Most of my short action calibers stabilize around 150 or so.

Yeah, my 6.5 did at about 80. But my 300 took awhile. I'm seeing sd's of 5-7 with with rl33 and about 3-4 inch groups at 1k.

 

[Matt_3479]

My barrel didn't get consistent until about 240 rounds.

Ouch I hope mine settles in before that! Otherwise 1/4 barrel life is well gone lol.

My 6creed didn’t settle till then,

 

[jmw]

Yeah, I think I'll dig up some Lee scoops, will save me time and headache. I can't really be bothered to buy a charge master just to throw N570, haha. What decapping die do guys use for .300 NM? My cheap Lee is too small for the case.

Redding

 

[dgheriani]

I was correct in my assumption that my barrel was still speeding up shot 2x 5rd groups today to check accuracy/zero and speed. Had to adjust zero up 0.2 and left 01. and barrel sped up by 40fps. Barrel currently sitting at 75rds. Will snowshoe/hike back out to my long range spot again this weekend and re-verify dope from 830-1600 yards.

temp: 45F
DA: 1067ft

group 1: 0.55moa
group 2: 0.49 moa

avg MV: 3188
ES: 26
SD: 8.7

I'm happy with the accuracy and speed, wouldn't mind seeing the ES come down but this is all virgin brass so we shall see.

 

[dgheriani]

I went back out and verified dope again on the 28th and was on at 830, 940, 1500, 1600 yards. Last 2 rounds I shot went high at 1600. Went back to range and verified speed and accuracy. Speed was up to 3203fps (over 10 rounds). Went back up to my long range spot this morning and verified dope. Everything lined up with what the Kestrel was telling me so I'm hoping the barrel is done speeding up as it's at 130 rounds.

temp: 39F
DA: 946ft

830 yards: 3.8 mils
940 yards: 4.7
1500: 10.2
1600: 11.6

Most likely won't check things again at 100 yards until I'm through the rest of my virgin brass (have another 70 to go) or if something seems off shooting at distance. Loving this cartridge though, man it hits targets like a freight train!

 

[tyfoon]

Hi, would you guys be willing to share your bullet jump & bullet combination you use ? I'm struggling with my group size even with very low SD.

 

[Runnineh]

Hi, would you guys be willing to share your bullet jump & bullet combination you use ? I'm struggling with my group size even with very low SD.

Sierra 230's with .02 jump has worked great for me. Hole on top of hole.