300 Norma Pressure Signs?

[eod_tek]

I'm having a difficult time doing load development and I'm also new to reloading so I'm not sure if these are pressure signs.
The load is 86.5 grains of n570, Lapua brass, 215m primers, and 215 Berger hybrids. I'm getting 3035 fps, and I've shot single shots over a magnetospeed up to 90.5 grains. I had a slightly hard bolt lift at 88 grains, but 88.5 and 89 weren't hard.
I loaded some up at 86.5, a velocity flat spot, and looking at the brass, I'm not sure if the powder on the back and slight cratering on the pirmers are a sign of pressure or not. I'm also getting a lot of residue on the necks.
I am also included a picture of once fired(not in my rifle, bought on the hide) unprepared brass next to twice fired. You can see a pretty significant difference between the two.
Looking for any feedback. The load data for n570 and 215s is all over the place and I just don't know.
Thank you!

 

[rustyinbend]

That's a bit of a hot load for 300-Norma, at least from my experience. I'd do a "back-off" ladder and see where I lose the primer craters ... that's always been a tell-tale sign of over-pressure for me. Are you getting a "heavy bolt" after firing? My 300-Norma reference load is:

 

[eod_tek]

I basically developed how I was going to load for it by splitting the Berger load data and VV load data in half (my oal is rigut between them anyways) and originally did a velocity ladder test from 84-90.5 grains. I had a slightly heavy bolt lift at 88 grains but not at 88.5, 90, or 90.5. I had a wide velocity flat spot at 84.5-85.5 (2940), one at 86.5-87 (3009) and one at 88.5 (3060) and then ended at 90.5 (3152).
VV said 87 is max and Berger suggests 92.4, but anecdotally, before I started reloading I shot factory federal and Berger ammoe, both with 215s and the Berger averaged 3009 and the federal 3045, so I'd anticipated those velocities as a target but probably conservative.
Being new to reloading I'm still learning a lot, but I don't want to be constantly running over pressure, but also want decent consistent performance from this rifle.
It is a 26 inch carbon wrapped barrel, and I've been anecdotally told that the Norma family of cartridges can be picky/finicky with carbon barrels?
Thank you for the inputs!

 

[rustyinbend]

I basically developed how I was going to load for it by splitting the Berger load data and VV load data in half (my oal is rigut between them anyways) and originally did a velocity ladder test from 84-90.5 grains. I had a slightly heavy bolt lift at 88 grains but not at 88.5, 90, or 90.5. I had a wide velocity flat spot at 84.5-85.5 (2940), one at 86.5-87 (3009) and one at 88.5 (3060) and then ended at 90.5 (3152).
VV said 87 is max and Berger suggests 92.4, but anecdotally, before I started reloading I shot factory federal and Berger ammoe, both with 215s and the Berger averaged 3009 and the federal 3045, so I'd anticipated those velocities as a target but probably conservative.
Being new to reloading I'm still learning a lot, but I don't want to be constantly running over pressure, but also want decent consistent performance from this rifle.
It is a 26 inch carbon wrapped barrel, and I've been anecdotally told that the Norma family of cartridges can be picky/finicky with carbon barrels?
Thank you for the inputs!

Yeah ... everyone comes at it through a different lens. I tend to care less about higher velocity, and more about single-digit SD, no pressure signs, and accuracy at distance. The load noted above with about 2900 for velocity and low SD's ... dings my 1-mile target just fine in my MPA Comp chassis with a 27-inch barrel. I believe that the lightest load that achieves my core objective (i.e. "accuracy at distance") is where I settle. A side benefit is that my barrel and brass both last longer with that strategy. To each his own ... eh?

 

[eod_tek]

Yeah ... everyone comes at it through a different lens. I tend to care less about higher velocity, and more about single-digit SD, no pressure signs, and accuracy at distance. The load noted above with about 2900 for velocity and low SD's ... dings my 1-mile target just fine in my MPA Comp chassis with a 27-inch barrel. I believe that the lightest load that achieves my core objective (i.e. "accuracy at distance") is where I settle. A side benefit is that my barrel and brass both last longer with that strategy. To each his own ... eh?

I 100% want that myself and am not necessarily chasing velocity, but in my reading it seemed like most cartridges were most accurate loads were nearer 100% case fill and near the top of velocity before pressure, so that's what I've been chasing. But what you're saying totally makes sense!
Do you think running n570 with 215s at a slower speed, that'd id run into combustion issues? I know n570 is favored for bigger projectiles, I just can't find any

 

[rustyinbend]

I 100% want that myself and am not necessarily chasing velocity, but in my reading it seemed like most cartridges were most accurate loads were nearer 100% case fill and near the top of velocity before pressure, so that's what I've been chasing. But what you're saying totally makes sense!
Do you think running n570 with 215s at a slower speed, that'd id run into combustion issues? I know n570 is favored for bigger projectiles, I just can't find any

I stick to Retumbo and H1000 for my magnum loads (300-WM, 300-PRC, 300-NM and 338-LM), and tend to use heavier bullets at slightly slower speeds for my "distance" over "velocity" strategy. Can't really comment on what to expect when shooting lighter bullets and N570 ... never been there. Luckily I've got "years" of supplies on the shelf (powder, primers, cases, bullets) so I can shoot my preference, instead of just what I can find. It's a blessing!

 

[Dogtown]

For what it's worth, I used to shoot 215s with 93gr of N570. That powder is almost perfect for .300NM, so that's not your issue.

The VV load data for .300NM seems a bit off, from what I've determined in recent years. Check out the responses to my post here. Going back and looking at my log book for my first barrel, I did an initial pressure ladder to find where my safe limits were using 88gr - 94gr and started seeing pressure signs at 94gr.

Pressure signs, in general, aren't deterministic. You're not going to get flattened primers followed by ejector marks and sticky bolt in that order. I've seen ejector marks with beautiful primers and vice versa, so you might not be hitting pressure unless maybe you're jamming into the lands and creating a pressure spike? Also, your primers aren't flattened. See the rounded edges? Yes, there is cratering at the point of impact, but that's not always a sign of pressure. In fact, I've often seen that with normal magnum-class loads.

Either way, the powder choice is not the issue.

 

[eod_tek]

For what it's worth, I used to shoot 215s with 93gr of N570. That powder is almost perfect for .300NM, so that's not your issue.

The VV load data for .300NM seems a bit off, from what I've determined in recent years. Check out the responses to my post here. Going back and looking at my log book for my first barrel, I did an initial pressure ladder to find where my safe limits were using 88gr - 94gr and started seeing pressure signs at 94gr.

Pressure signs, in general, aren't deterministic. You're not going to get flattened primers followed by ejector marks and sticky bolt in that order. I've seen ejector marks with beautiful primers and vice versa, so you might not be hitting pressure unless maybe you're jamming into the lands and creating a pressure spike? Also, your primers aren't flattened. See the rounded edges? Yes, there is cratering at the point of impact, but that's not always a sign of pressure. In fact, I've often seen that with normal magnum-class loads.

Either way, the powder choice is not the issue.

Thank you, it's good to know that I can probably eliminate powder as any issue. I was partially thinking it may be pretty low in load and maybe I needed to step it up, but this barrel has also been finicky (I think). I have a borescope and had a decent carbon ring, got that cleared out, and after 30 rounds it was starting the develop again. I've gotten powdery soot on the back of rounds and necks quite frequently, which I read can be from not using enough powder.
I don't think I'm in the lands. I've tried 3 different methods of finding the lands and have come back consistently with a CBTO of 2.7785 and I've been loading 20 thousandths off this far.
I did a velocity test and have tried loading at the middle of a flat spot (86.5 grains/3009fps) and did a seating depth test from 18-30 thousandths in 3 thousanth increments and at best got 1moa of accuracy. Obviously I know I can be a factor in that, but overall I think I should be seeing better results than that.
I'm considering loading up an ocw test going from 85-91 at 50 thousandths off and seeing if I get any different results. Hopefully I'd see a similar velocity flat spots and maybe better groups if I jump them further. Seems like a lot of people have good luck jumping hybrids between 40 and 70 thousandths.

 

[Chris M.]

Did you ever get your load development finalized with 215 Bergers and N570?

From a previous post on this site, giving credit to the original author, bellow:

 

[eod_tek]

Did you ever get your load development finalized with 215 Bergers and N570?

From a previous post on this site, giving credit to the original author, bellow:

View attachment 8157535

View attachment 8157536

I haven't yet, I switched over to 245s and got a decent load worked up, but I'm almost out of them so I'm going to start working on them again soon. That will definitely be helpful!

 

[Taylorbok]

I know of 5 300 Norma's and they all shoot really well with 85gr of N570 with 245 bergers or 250 a-tips

 

[eod_tek]

I know of 5 300 Norma's and they all shoot really well with 85gr of N570 with 245 bergers or 250 a-tips

I must just have a weird rifle or a scale that's consistently off, because I have low es and sds but I hit pressure around 83-84 grains of n570 and 245s. I can get 2890fps then I start getting stuff bolt lift and ejector marks.

 

[Dogtown]

I know of 5 300 Norma's and they all shoot really well with 85gr of N570 with 245 bergers or 250 a-tips

It's also a sweet spot I'm finding with N170, which burns a bit cooler than N570 and may not wear out barrels as quickly. Albeit with velocity reduced by 100-150fps (but still 2945fps out of a 30" barrel).

 

[Gorillla]

I'm having a difficult time doing load development and I'm also new to reloading so I'm not sure if these are pressure signs.
The load is 86.5 grains of n570, Lapua brass, 215m primers, and 215 Berger hybrids. I'm getting 3035 fps, and I've shot single shots over a magnetospeed up to 90.5 grains. I had a slightly hard bolt lift at 88 grains, but 88.5 and 89 weren't hard.
I loaded some up at 86.5, a velocity flat spot, and looking at the brass, I'm not sure if the powder on the back and slight cratering on the pirmers are a sign of pressure or not. I'm also getting a lot of residue on the necks.
I am also included a picture of once fired(not in my rifle, bought on the hide) unprepared brass next to twice fired. You can see a pretty significant difference between the two.
Looking for any feedback. The load data for n570 and 215s is all over the place and I just don't know.
Thank you!

I had weird over pressures. My issue was carbon ring above the neck at the chamber boundary. Cleaned the $hit out of it with barrel paste. Off to the range tomorrow.

 

[eod_tek]

I had weird over pressures. My issue was carbon ring above the neck at the chamber boundary. Cleaned the $hit out of it with barrel paste. Off to the range tomorrow.

I'm interested to hear your results. I had a carbon ring at one point, have cleared it out and still seem to have pressure signs early. I think maybe I just have a tight bore. For example, I just did a pressure test with 215 hybrids and n565, and started seeing heavy bolt lift around 3025fps and had ejector marks around 3085. I also tried a pressure test with n570 and 245 hybrids and couldn't get them last 2925 without ejector marks and stiff bolt lift.

 

[Gorillla]

I’ve had five high pressure events. Not sure if I’ve trashed my chamber, or if it’s the Peterson brass because I’ve got brass stuck in my Whidden sizing die right now(2nd resize). I’m using 230 Berger OTM with 82.5/81.5 N565 .040 off the lands. Pretty tame load as far as other posters.
Curious if Barrett would look at it.

 

[Chris M.]

I had weird over pressures. My issue was carbon ring above the neck at the chamber boundary. Cleaned the $hit out of it with barrel paste. Off to the range tomorrow.

EOD Mickelson and Gorrilla here is some data which may help you guys, not the same bullet but it should be applicable to the 2015 Bergers. With the 300 Norma, I think there is a velocity node with a 26" barrel around 3030 fps-3065 fps (depends on the bullet and powder). I have rifles chambered in 300 Norma and they both shoot really, really well around those velocity nodes. The Temp. I shot at was at 107 degrees not 104. Here is my most relevant data, hope this helps:

I will be conducting more testing in the near future: I also have a load with 87.0 grain of BMG-50 that is shooting one hole at 100 meters with 225 grain ELD-Ms; I'm almost at Jam on that load maybe 3-4 thousands off the Lands. I haven't measured velocity yet as I was just breaking in the rifle (same rifle 26" barrel). 50 BMG powder is an extreme powder so I think it is worth my time to start documenting Temp./Speed variation at different temperatures.

EOD Mickelson, thank you for your service! - Chris

 

[eod_tek]

EOD Mickelson and Gorrilla here is some data which may help you guys, not the same bullet but it should be applicable to the 2015 Bergers. With the 300 Norma, I think there is a velocity node with a 26" barrel around 3030 fps-3065 fps (depends on the bullet and powder). I have rifles chambered in 300 Norma and they both shoot really, really well around those velocity nodes. The Temp. I shot at was at 107 degrees not 104. Here is my most relevant data, hope this helps:

View attachment 8183188



I will be conducting more testing in the near future: I also have a load with 87.0 grain of BMG-50 that is shooting one hole at 100 meters with 225 grain ELD-Ms; I'm almost at Jam on that load maybe 3-4 thousands off the Lands. I haven't measured velocity yet as I was just breaking in the rifle (same rifle 26" barrel). 50 BMG powder is an extreme powder so I think it is worth my time to start documenting Temp./Speed variation at different temperatures.

View attachment 8183190

EOD Mickelson, thank you for your service! - Chris

Thank to for the support!

Also, thank you for the data. I'm running N565 with my 215s and top out around 3k before I see pressure. I have some N570 and know I can push it to closer to 3100, but this load is for hunting and as long as it's consistent, 3k is fast enough for my needs. I will however, use N570 for shooting the 245s or maybe 250s at next years NF ELR steel challenge.
My biggest issues with N570 is how darn hot it burns, I completely believe it will eat the barrel up much faster than Retumbo, H1000 or N565/8, and it meters awfully in my matchmaster. After loading hundreds of rounds of N570, switching to 565 was such a relief.

 

[Bacarrat]

I think it might have something to do with the freebore. When I first got my Proof barrel on, even some of the lightest loads will produce pressure issues. Had a local smith recut the freebore out .050-.060 and pressure issues went away. Currently also running N565 with the 215gr Hybrids and can get it up there in speeds, haven't truly seen over pressure yet as accuracy was satisfactory with the 87.5 load. Will probably start the load development with the N570 soon as I think it should be easily over 3100FPS with that powder.

 

[Chris M.]

Thank to for the support!

Also, thank you for the data. I'm running N565 with my 215s and top out around 3k before I see pressure. I have some N570 and know I can push it to closer to 3100, but this load is for hunting and as long as it's consistent, 3k is fast enough for my needs. I will however, use N570 for shooting the 245s or maybe 250s at next years NF ELR steel challenge.
My biggest issues with N570 is how darn hot it burns, I completely believe it will eat the barrel up much faster than Retumbo, H1000 or N565/8, and it meters awfully in my matchmaster. After loading hundreds of rounds of N570, switching to 565 was such a relief.

You are very welcome!

FYI: the VV 500 powder series including N565 and even N568 (both are advertised as very Temp. stable, N568 may be a good powder to try to lower peak pressures in your rifle) are all double based powders (peak internal Temp. can reach up to 4,400 degrees VS single based typically reach up to 3,800 Degree in peak internal temperatures) but VV has figured out a way of making the N565 and N568 to be very Temp. stable. I will be trying N568 in 300 Norma soon with 210-212 gr. bullets for hunting loads...

There is a consensus that double based powders will wear out barrels (primarily due to increased heat) more quickly then single based powders by how much, is not clear to me, for hunting applications probably much less so then shooting in competition where you may have to put multiple rounds through it in relatively quick succession. FYI: proof research is making the aftermarket barrels as an OEM replacement for Barrett (their gunsmith and I spoke; not sure the Proof barrels are exactly the same or from the same steel) and the 300 Norma the Steel barrels used by SOCOM are lasting up to and around 2,000 rounds under normal firing conditions using Norma 217 powder (so for sniper support missions and training) which has very similar Nitroglycerine content to N570.

In the Barrett, I am using 230 gr. A-tips (1 in 10" twist barrel not the 1 in 8" twist barrel) which are supper accurate (using a revised BC, not the Hornady or Applied Ballistic data) with Norma 217 at 3065 fps so I ended up buying N570 to maybe replace that powder as Norma 217 has been completely unattainable for the past 3 years.

Here is what VV says about the N500 powder series: "The N500 series of Vihtavuori propellants provide the utmost in performance for added velocity and range with heavy bullets. Nitroglycerine has been added to the traditional single base powder to get better energy content. The series offers eight different reloading powders with different burning rates". N568 has smaller kernels then N570 (similar in size to N560) and comes back every 3-6 months in the supply chain on Midsouth Shouters and Mile High Shooters supply (both are in stock now, it is expensive but not much more then H-1000 which is also available on Midsouth right now).

If you find a good load with H-1000 please do share, I primarily use that powder with the 300 WM but so far have not tried it for the 300 Norma, mostly because I am a bit concerned about getting good case fill. sd

Best regards - Chris

 

[eod_tek]

Looking to rehash this again with some new data. I just want to see if I'm missing something.
With my old barrel (26" proof carbon 1:9), N570, Lapua brass, 215M primer, I was getting pressure signs (extractor mark followed by mark and heavy bolt lift) at 2925fps with Berger 245 EOLs. Looking at other people's load data It seemed like that might be a little slow, but I somewhat attributed it to potentially being an issue with that barrel or maybe in the way the chamber was cut. I have since put a new barrel on the rifle, it's a Bartlein 26" steel barrel, also 1:9, It was cut by a different gunsmith using a different reamer, and I saw the same pressure signs at about the same velocity. Seeing people's N570 loads as well as other powders, I feel like I should not be starting to have pressure just after 2,900 ft per second.
For more context, I am using a matchmaster for powder, Forester dies for seating, bumping the shoulder .002 using bullet central sizing die and seat the bullet at .070 off the lands, COAL of 3.698.

I'm not necessarily trying to hot rod this thing, but I also don't want to leave a ton of velocity on the table because I live in a windy area in like every advantage I can to beating the wind. And why have a Norma if you can't push big bullets fast

 

[Dogtown]

It would help to know what bullet you’re comparing velocity with?

 

[eod_tek]

It would help to know what bullet you’re comparing velocity with?

All that data and I forgot the bullet! It's been a day. I'm shooting 245 EOLs

 

[Dogtown]

2925 fps for 245s out of a 26” is really good. For comparison, I have a comfortable N170 load with 250s out of a 30” around 3000fps. With N570 I get about 3075fps.

So I think you’re good.

 

[Bacarrat]

I was getting pressures out of the factory Proof barrel too. Couldn't get it up to speed with any powder. Had a local gunsmith extend the freebore .050 to .060 and most of the pressure went away. Currently pushing 215gr Bergers 3135FPS with about 91.5gr of N570.

 

[918v]

At what coal is your load?

 

[Gorillla]

Have you scoped the barrel? My guess is you have a carbon ring; nothing to be trifled with. Trashed my Barrett after 270+ rounds cause I wasn’t cleaning enough.