Berger’s twist rate stability calculator says you’re fine
https://bergerbullets.com/twist-rate-calculator/
https://bergerbullets.com/twist-rate-calculator/
But what is your air density? I'm at sea level and during the summer months my 1/9 twist is fine with an air density of +150 ft but when the temperature drops below 20 F I start to see air density readings of -2000 ft and when it gets down to below 0 or below I see air density readings of -6000 ft. At a 1000 yards my groups were opening up considerably when it's cold. I was baffled why the same load was suddenly giving me fits until I ran the numbers with the Berger twist rate calculator and an elevation of -2000 ft it shows a 230 as marginally stable 1.42. At 1/8 twist gives you a 1.79. So I went to a lighter 215 Berger which is slightly more stable bullet for winter months until this barrel is wore out and I can get a 1/8 spun up for next year.
No was just wondering. Everyone I talked to, or read have said 1/9 for 230's. I'm close to 6000 ft of elevation. Had a 1/8 on my ASR. But want a 1/9. Just didn't know why you were having issues. Good to know. Merry Xmas.
Whats the best combo for the 250 A Tips out of a 26" barrel. I've got H1000, N565, N568, RL33 and Retumbo to work with. Also have ADG or Lapua brass and CCI LRM's or Fed 215 GMM's. Should I drop back to the 230 A tips with 26" tube.
Should I grab some N570?
Not necessarily. I think it’s the best overall performing powder for a range of bullets in .300NM, but it’s notorious for reduced barrel life. I still use it though, but one of my barrels performs so well above others that I use N170 instead (less heat than N570), but that results in less velocity. So it really depends if you favor performance over barrel life.
N568 is a good alternative.
N568 is a good alternative.
Where would you start for load development?
Thanks!
I just found 10 lbs of 570 that I forgot I had... Start at 77/78gr if I go with it instead?
With a 250gr ATip and n570 I was comfortable enough to test 86.0, 86.5 and 87.0 and pick the best out of those.
What brass were you using?
Lapua
Hey gents, hoping someone can help me out here. I couldn't find what I was looking for in the last few pages.
Forgive my lack of knowledge on the 300NM. I've got my buddy's MRAD SMR with me for a bit, and was messing with it today. I'll be working up a load for him, but he did leave me a box of factory Norma Match with the 230gr Berger Hybrid.
Ho-Lee-Fuk. His rifle hammers with that load. I only shot it at 100 and 385 from my porch today, but it cranked out a half-minute group at 385 (2").
I'm no longer interested in trying to develop something new, but rather sleuth the factory load. I've got all the measurements...but it is using 86.3 - 86.4gr of a powder that I am unfamiliar with. I'll attach a crappy photo of it.
Anybody have an idea of what powder it may be? Obviously the charge weight narrows it down, but i dont have any magnum powders on hand other than H1000, and it definitely isn't that.
I've left the deconstructed round apart so that I can dump the powder out and compare.
Maybe N570??
Any insight is greatly appreciated.
Forgive my lack of knowledge on the 300NM. I've got my buddy's MRAD SMR with me for a bit, and was messing with it today. I'll be working up a load for him, but he did leave me a box of factory Norma Match with the 230gr Berger Hybrid.
Ho-Lee-Fuk. His rifle hammers with that load. I only shot it at 100 and 385 from my porch today, but it cranked out a half-minute group at 385 (2").
I'm no longer interested in trying to develop something new, but rather sleuth the factory load. I've got all the measurements...but it is using 86.3 - 86.4gr of a powder that I am unfamiliar with. I'll attach a crappy photo of it.
Anybody have an idea of what powder it may be? Obviously the charge weight narrows it down, but i dont have any magnum powders on hand other than H1000, and it definitely isn't that.
I've left the deconstructed round apart so that I can dump the powder out and compare.
Maybe N570??
Any insight is greatly appreciated.
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N570 has way bigger kernels. Could be N568 or N565.... or their own commercial grade powder Norma only has.
Not fat enought for n568 and if it's norms brand I would think it's norma powder like picture above would be a good start
Diggler, it's Norma ammo, therefore as mentioned above, would look at a Norma powder. Identifying powder visually is probably not the best way to approach this. That being said, the Vihtavouri powders for 300 NM (N170, N565, N568) I'm familiar with are not as uniform as your picture. Diameter fairly consistent, length and clean cut ends not so much.
And why would I even know this? Because I have an Ingenuity Trickler and conversed with Paul in trying to find the correct disk for N170. In our conversation(s), he indicated Vihtavouri powders, at least in that series are not all that consistent. I defer to his knowledge and my observations.
And why would I even know this? Because I have an Ingenuity Trickler and conversed with Paul in trying to find the correct disk for N170. In our conversation(s), he indicated Vihtavouri powders, at least in that series are not all that consistent. I defer to his knowledge and my observations.
I appreciate the help gents.
As far as I know, Norma powder is no more. I already tried to find some 217 as it made the most sense. Powder Valley, Midsouth, and Midway no longer list Norma powders, and there are threads dating back a couple years on other boards stating that Norma is gone.
So either Norma is using a proprietary blend not commercially available (absolutely possible as their advertised velocity is pretty hot), or they have been using something from another company.
As far as I know, Norma powder is no more. I already tried to find some 217 as it made the most sense. Powder Valley, Midsouth, and Midway no longer list Norma powders, and there are threads dating back a couple years on other boards stating that Norma is gone.
So either Norma is using a proprietary blend not commercially available (absolutely possible as their advertised velocity is pretty hot), or they have been using something from another company.
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Was hoping to get some help diagnosing my Norma build.
I've got 18 rounds down the pipe and 2 light primer strikes.
The firing pin channel did have a tiny bit of crap in it so I cleaned that out.
Headspace:
Zeroed on go-gauge
Fired brass +.003"
Virgin brass -.0065"
Primers are seated -.008" (on primers that didn't ignite) CCi 250's
This was all measured with calipers so take it for what it is. Is this where my issues are? Or are these numbers inline with what you guys are seeing?
I've got 18 rounds down the pipe and 2 light primer strikes.
The firing pin channel did have a tiny bit of crap in it so I cleaned that out.
Headspace:
Zeroed on go-gauge
Fired brass +.003"
Virgin brass -.0065"
Primers are seated -.008" (on primers that didn't ignite) CCi 250's
This was all measured with calipers so take it for what it is. Is this where my issues are? Or are these numbers inline with what you guys are seeing?
What kind of trigger do you have? Way back in the day, I would get light primer strike with a Timney trigger. Turns out the sear engagement was off on the trigger causing this issue.
It's a trigger tech special in an American rifle company CDG, it's got the trigger hanger so timing is easy to adjust.
Your brass is growing near 0.010" and your seating primers 0.008" deep. I'm not surprised you're getting light strikes. Lapua brass shouldn't be 0065 short of gauge, then ur Smith cuts to go +003? Headspace sounds a bit deep. Stop seating your primers -008, only go to flush or max of -002 until your brass is formed.
That's kinda what I though with the tolerance stacking. I cut the chamber but didn't think it was long but the numbers don't lie.
The headspace isn't a big problem other than the fireform pains. Lapua is tough stuff and likely won't be fully formed for a few firings. Primer depth will make a difference on consistency of ignition.
Jackomason: Was halfway through a reply this morning before I was interrupted by work (screw them dead lines). My thoughts are pretty much the same as 406Shootist. I'm just recently getting into primer depth seating testing. My Lapua brass has primer pocket depths of 0.127", CCI 250 primer depth is 0.125". Seating the primer -2 or -3 thou would bottom out the anvil and seems more appropriate. I haven't fired the Lapua brass yet, but the Peterson brass has very similar dimensions and consistency. New Peterson brass base to datum line = 2.023", Once fired dimension = 2.033". So the growth is close to yours. Of course your dimensions are probably different and like you, my measurements were with calipers, so there's some plussing and minusing going on.
As a side note, I'm retiring the Peterson brass after 8 firings. The last batch of ammo I shot had 9 firings and out of 30 rounds, about 7 had significant case head separation. But there were some hot loads run during load development. We'll see how the Lapua does.
Good Luck
As a side note, I'm retiring the Peterson brass after 8 firings. The last batch of ammo I shot had 9 firings and out of 30 rounds, about 7 had significant case head separation. But there were some hot loads run during load development. We'll see how the Lapua does.
Good Luck
I just chambered a barrel and set headspace to my current lot of Peterson brass. The other 300nm I have on hand is chambered by Bartlein with an identical reamer and headspaced to the gauge. That barrel is .010” deeper than the one I did.
Saami was recently released. The 0.455 shoulder headspace datum line has a 0.010 range. Seems a bit excessive. If I were chambering a new 300nm barrel I'd prob use a new piece of brass as go, and chamber 0.003 deep of that.
26 Inch barrel or longer?
Yes, it’s a good fit for the lighter bullets. N565, N568, and N570 are all very well suited for .300NM.
Ive looked all over the internet and can't seam to find anything on 245 eol bullets in a .300 norma with H1000. Seems like most guys are running N570. I have a couple jugs of h1000 and would like to stick with that if possible. Does anyone have any loads they would like to share with this bullet powder combo as well as velocity they are getting? I'm using Lapua brass. Thanks
H1000 works great with the 215 gr. bullets but it's a bit to fast for the heavies. I can't find N570 so I've been using H50bmg and Staball HD(same burn rate as Retumbo).
N570 just dropped at a bunch of places. PV has a crazy good price for the 8lbs jugs.
www.powdervalley.com
Vihtavuori N570 Smokeless Gun Powder
Reload your ammunition with Vihtavuori N570 smokeless powder from Powder Valley. Experienced reloaders know that using premium powder is the key to consistency.
www.powdervalley.com Any experience/ advice on loading for a 22” bbl’d 8 twist standard Norma in a hunting configuration?
Plenty of h1000, retumbo… still about 2 months left on my build, but I can’t stop thinking about loading.
Kelbly Nanook
22” ace 8twist
Manners Nimrod
UM bottom metal/ TT special
This is what is spec’d out at the moment. Wanting to run suppressed, hence the 22”
Plenty of h1000, retumbo… still about 2 months left on my build, but I can’t stop thinking about loading.
Kelbly Nanook
22” ace 8twist
Manners Nimrod
UM bottom metal/ TT special
This is what is spec’d out at the moment. Wanting to run suppressed, hence the 22”
Very interested in hearing your results with the ace barrels. They look like a great option with a great price. I'm guessing Unknownmunitions doing the work I also interested in hearing your thoughts on them.
Heard nothing but good about Ace barrels. First one for me, but the first time I heard about them was from Bruce Thom at BAT machine. He was using them and recommended them. (Pretty good recommendation)
Unknown is doing the work. First met Jake and his wife when they were working out of their garage They’re about 2 miles from me. Awesome shop. Good people with a passion and doing business in a way that they’ll be successful. Knowledgeable and helpful staff all around.
Unknown is doing the work. First met Jake and his wife when they were working out of their garage They’re about 2 miles from me. Awesome shop. Good people with a passion and doing business in a way that they’ll be successful. Knowledgeable and helpful staff all around.
Probably already been addressed at some point, but ask anyways:
For 300 Norma Mag Lapua brass, what size neck bushing do you all find to be best?
Got a new Barrett MRAD 300 Norma barrel and I want to start working up a load, but I got to get a neck bushing die first and I don't want to get the wrong one.
For 300 Norma Mag Lapua brass, what size neck bushing do you all find to be best?
Got a new Barrett MRAD 300 Norma barrel and I want to start working up a load, but I got to get a neck bushing die first and I don't want to get the wrong one.
Just recently started using the Lapua brass bought in early 2021. Brass with one firing, neck OD with bullet = 0.339”. Which would work out to a neck wall thickness of 0.0155”. Been using a 0.337” bushing followed by a 0.306” mandrel to make the hole more uniform/consistent. No guarantees your brass and measurements will be the same. Usual disclaimer … YMMV.
Just started playing with my buddy's 300NM. It shot great with factory 230gr Norma stuff, but all he had for supplies when he dropped the rifle off with me was 215gr Berger Hybrids and H1000. He has 230gr Hybrids and N570...but that doesn't help when you don't bring it 
.
Anyway, just did a few rounds at 2.800 CBTO (.060 off), and worked my way back in .010 increments. I used 82gr of the H1000 as a safer starting point with CCI 250s. Third group showed promise (100 yards) at 2.780 CBTO.
I grabbed my inertial puller and hammered the next set out before re-seating at 2.780. I had to take a break, but got back this afternoon to test fire again, and was happy to see this despite the wind picking up a little.
I'm still cautious, but I'll try this at a bit of distance and see if it continues to hold up. I also need to get it over my chronograph and bump up charge weight until either the accuracy goes away or the velocity gets to where I want it.
It's a good start
.Anyway, just did a few rounds at 2.800 CBTO (.060 off), and worked my way back in .010 increments. I used 82gr of the H1000 as a safer starting point with CCI 250s. Third group showed promise (100 yards) at 2.780 CBTO.
I grabbed my inertial puller and hammered the next set out before re-seating at 2.780. I had to take a break, but got back this afternoon to test fire again, and was happy to see this despite the wind picking up a little.
I'm still cautious, but I'll try this at a bit of distance and see if it continues to hold up. I also need to get it over my chronograph and bump up charge weight until either the accuracy goes away or the velocity gets to where I want it.
It's a good start
Anyone load any 120gr bullets? Ive got a box of solid copper 120s here and thought they would be fun on coyotes
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