230 A-Tip in .300 Norma Magnum Improved -- Load Help?

[wjplohman]

I'm getting ready to try 230 Atips with retumbó. Rifle is a .300 Norma Magnum Improved (NMI) with 34" barrel 8.5 twist. Just wondering if anyone has tried something similar. I'm really interested in how this bullet performs going through the transition zone as I'm looking to reach out to close to 3000 meters. From previous bullet experience with this rifle I'm expecting to get around 3150 fps out of it
or will be looking for a node around that range

 

[Ledd Slinger]

You won’t reach 3000 meters with any sort of consistent accuracy. I’d put a cap at 2,000 meters or you’re just wasting time and ammo.

 

[Kurz]

You won’t reach 3000 meters with any sort of consistent accuracy.

Yes.

Your suggested powder will probably operate in that velocity range but it's the top of the pressure curve and you have no guidance on accuracy or consistency.. My best results came from VVN-568 with the A-Tips.

 

[Taylorbok]

I can't help you with that bullet but I know of a bunch of standard 300 NM running the 250/245 with 85gr of N570, seems to be a sweet spot there

 

[davidjoe]

Retumbo is a good powder choice.

I’m on a personal quest to make the 250’s and to a degree, the 230’s work in string fire Fclass.

Here’s the situation with them as I see it on the 250’s and 230’s:

1) the 250’s, especially, flat trounce other 30’s in wind drift, and I just saw this again as of Sunday;

2) I shot them at over 2,850 with Retumbo from a 300 Win Mag;

3) I got two no reads when the barrel was hot even with generous HBN coating, and had to revert to the bullets I started with, but they shot SO well, better with stout Retumbo charges than h-1000, and no less than 9 inches less drift than I had with the 245 EOL’s;

4) I have eight 5R 1:8 barrels currently mounted in rotation and they will ALL blow up 250’s, if I am not exceedingly careful, and all shoot potentially better than I can with anything else, if they do not blow up;

5) I predict you won’t string fire them, but will still occasionally lose them, because of the cartridge size.


This is truly a trap, if you don’t push them hard, you won’t like the results of 230’s. If you do push them hard, you must be cognizant of fragility.

I suspect I blew up 5 in a row of 230’s last month at 600. Infuriatingly, I moved to an etarget not in use and finished out the string with the exact same bullets with ZERO no reads and an incrementally hotter barrel, leaving doubt about what was going on.

I’m having two 8.5 twist barrels finished this week and one of them is deliberately going to have 3 inches cut off the muzzle, which absolutely kills me to do because I don’t know if it will help, it will most certainly slow them down, and these are up charged for both length and 1.5” bar stock. I hate being put in that position.

If the 250’s were a prize fighter, then they would have to be described as brutally unmatched in strength but with a glass jaw.

I can’t make the 230’s rival the 250’s yet at 1,000 and I no longer believe they are immune to blow ups, so they aren’t high on my list right now.

 

[Ledd Slinger]

Retumbo is a good powder choice.

I’m on a personal quest to make the 250’s and to a degree, the 230’s work in string fire Fclass.

Here’s the situation with them as I see it on the 250’s and 230’s:

1) the 250’s, especially, flat trounce other 30’s in wind drift, and I just saw this again as of Sunday;

2) I shot them at over 2,850 with Retumbo from a 300 Win Mag;

3) I got two no reads when the barrel was hot even with generous HBN coating, and had to revert to the bullets I started with, but they shot SO well, better with stout Retumbo charges than h-1000, and no less than 9 inches less drift than I had with the 245 EOL’s;

4) I have eight 5R 1:8 barrels currently mounted in rotation and they will ALL blow up 250’s, if I am not exceedingly careful, and all shoot potentially better than I can with anything else, if they do not blow up;

5) I predict you won’t string fire them, but will still occasionally lose them, because of the cartridge size.


This is truly a trap, if you don’t push them hard, you won’t like the results of 230’s. If you do push them hard, you must be cognizant of fragility.

I suspect I blew up 5 in a row of 230’s last month at 600. Infuriatingly, I moved to an etarget not in use and finished out the string with the exact same bullets with ZERO no reads and an incrementally hotter barrel, leaving doubt about what was going on.

I’m having two 8.5 twist barrels finished this week and one of them is deliberately going to have 3 inches cut off the muzzle, which absolutely kills me to do because I don’t know if it will help, it will most certainly slow them down, and these are up charged for both length and 1.5” bar stock. I hate being put in that position.

If the 250’s were a prize fighter, then they would have to be described as brutally unmatched in strength but with a glass jaw.

I can’t make the 230’s rival the 250’s yet at 1,000 and I no longer believe they are immune to blow ups, so they aren’t high on my list right now.

How fast are you pushing the 230’s? I have run them up to 3200 fps with a 10” twist with no issues. I also had an 8” twist in my first 300 NMI and pushed them up to 3100 fps with no issues. Just didn’t like that 8” twist rate for the 230s, it’s too fast. Went to a 9” twist on my 2nd 300 NMI because I decided I would never run anything heavier than 230gr, and again no issues. Now on my 3rd 300 NMI and running a 10” twist which is great. Tho in my testing and personal opinion, I think a 9.5” twist would be perfect for 215gr and 230gr bullets in the NMI, but the 10” works really good for me at 3,000-6,000 ft of elevation.

I also know better than to run a cartridge that big on long strings of fire, so not like the barrel was ever piping hot. Usually 2 or 3 - three shot groups, then I let it cool down for a bit.

There’s a reason guys don’t use large Lapua magnums in F-Class and Benchrest and it sounds like you are spending a ton of money to learn that lesson the hard way. Could have just asked and we would have told you that ain’t gonna work

 

[rardoin]

@davidjoe David, when I ran the 190 A-tips I calculated that I had to slow them down to well under 2700fps to get them even with a 215 hybrid at 2850fps. If you can get them slow enough perhaps they will hold together. A half minute less drift at 1000yds would definitely prove advantageous...if they are grouping tight enough. Although I have not run the ballistics, that may be accomplished at a bit less velocity than you are pushing them. Just some musings after bruising my forehead repeatedly with the 190's.

Robin

 

[davidjoe]

How fast are you pushing the 230’s? I have run them up to 3200 fps with a 10” twist with no issues. I also had an 8” twist in my first 300 NMI and pushed them up to 3100 fps with no issues. Just didn’t like that 8” twist rate for the 230s, it’s too fast. Went to a 9” twist on my 2nd 300 NMI because I decided I would never run anything heavier than 230gr, and again no issues. Now on my 3rd 300 NMI and running a 10” twist which is great. Tho in my testing and personal opinion, I think a 9.5” twist would be perfect for 215gr and 230gr bullets in the NMI, but the 10” works really good for me at 3,000-6,000 ft of elevation.

I also know better than to run a cartridge that big on long strings of fire, so not like the barrel was ever piping hot. Usually 2 or 3 - three shot groups, then I let it cool down for a bit.

There’s a reason guys don’t use large Lapua magnums in F-Class and Benchrest and it sounds like you are spending a ton of money to learn that lesson the hard way. Could have just asked and we would have told you that ain’t gonna work

The 300 Win Mag was the popular prone match cartidge before the 6.5 .284 came on the scene. Recoil without better ballistics was major reason for change.

That money’s already spent, in all I must have 65k A-Tips mainly in 4 calibers/weights and I’m happy to have them, despite challenges. This was a read of the 230’s from a while back.

It’s a little more complicated than Lapua mag won’t work. With the 250 A-Tip having come out, there is literally no .338 match bullet with its BC, and the .338 LM can not only not compete in BC, but it was actually hard pressed to challenge the 195 EOL in a Suam even before that, I’ll say that even a .284 with 195’s shot inside it. I have used it (none blow up, but I feel silly adding a ring to a 7’s hold). I’d be shooting 300 grain bullets with a lower BC, slower. It would be counterproductive.

If I were making 250 grain 30 cal bullets, I would anticipate that the Win Mag to be at the smaller end of what they will be shot with, and it’s actually probably the smallest cartridge feasible right there with their own 300 PRC. We do have to keep in mind that the absolute highest BC combination on the line recently was one extremely rare blow up away from winning the LR national match last year. It’s going to happen. Wasn’t long ago everyone swore by their .284’s, and now, they don’t.

I do realize that my twist rate isn’t needed for 230’s but it’s only a bit faster than the 8.5 minimum for 250’s, and I had them made for the 250’s.

Here’s the thing about the 230’s they don’t actually have a much higher BC than the 190’s, but the 250’s do, by a lot. And I think they may be the smallest shooting until the 110 A-Tip, which is an extremely good bullet.

 

[davidjoe]

@davidjoe David, when I ran the 190 A-tips I calculated that I had to slow them down to well under 2700fps to get them even with a 215 hybrid at 2850fps. If you can get them slow enough perhaps they will hold together. A half minute less drift at 1000yds would definitely prove advantageous...if they are grouping tight enough. Although I have not run the ballistics, that may be accomplished at a bit less velocity than you are pushing them. Just some musings after bruising my forehead repeatedly with the 190's.

Robin

They released the 190’s last. Heavy 7’s are the heart of LR matches and they were ultra cautious. We all knew the reputation. Humor abounded. That’s actually one of their tougher bullets. Yeah, I have personally, in sighters, tested it head to head in Phoenix where I had it loaded to strike a foot and a half lower than the 195, tipped, and YET even slower, it hit 10 inches further INTO the wind than the 195. That was sure something to reflect on. I have them, but I do seem to get smaller groups with 195’s.

None of these heavies will shoot smaller when there is moderate or no wind, probably not even as small. They can’t save a nine, where a nine wasn’t going to be shot. The 195 is mean bullet though.

 

[Ledd Slinger]

The 300 Win Mag was the popular prone match cartidge before the 6.5 .284 came on the scene. Recoil without better ballistics was major reason for change.

That money’s already spent, in all I must have 65k A-Tips mainly in 4 calibers/weights and I’m happy to have them, despite challenges. This was a read of the 230’s from a while back.

It’s a little more complicated than Lapua mag won’t work. With the 250 A-Tip having come out, there is literally no .338 match bullet with its BC, and the .338 LM can not only not compete in BC, but it was actually hard pressed to challenge the 195 EOL in a Suam even before that, I’ll say that even a .284 with 195’s shot inside it. I have used it (none blow up, but I feel silly adding a ring to a 7’s hold). I’d be shooting 300 grain bullets with a lower BC, slower. It would be counterproductive.

If I were making 250 grain 30 cal bullets, I would anticipate that the Win Mag to be at the smaller end of what they will be shot with, and it’s actually probably the smallest cartridge feasible right there with their own 300 PRC. We do have to keep in mind that the absolute highest BC combination on the line recently was one extremely rare blow up away from winning the LR national match last year. It’s going to happen. Wasn’t long ago everyone swore by their .284’s, and now, they don’t.

I do realize that my twist rate isn’t needed for 230’s but it’s only a bit faster than the 8.5 minimum for 250’s, and I had them made for the 250’s.

Here’s the thing about the 230’s they don’t actually have a much higher BC than the 190’s, but the 250’s do, by a lot. And I think they may be the smallest shooting until the 110 A-Tip, which is an extremely good bullet.

Yeah but you can’t expect BC to make up for lack of wind reading ability. I think sometimes people get hung up on BC too much. Same with Standard Deviation on velocity. Just go with what the rifle and targets are telling you and to hell with the rest.

Accuracy during good calm conditions is what you want to achieve. Then test for temp stability and learn to read the wind with that bullet. Regardless of BC, any good bullet can win if the accuracy is there and the shooter is skilled enough. Might get lucky and have a high BC save you a bit on an errant wind call every now and then, but if you can’t make good calls all the time, just not gonna win.

The 308 Baer was big in bench rest before the 6.5-284. Then came the Dasher and 6.5x47, and now the 6BRA. So you can see the direction the case capacity has gone. Recoil is a big factor in a rifle shooting small as well. The guys can run 10 rounds on a 6mm in under 20 seconds to get bullets on target in similar wind conditions while not having to worry about stringing due to barrel heat.

Try running a 300 win mag or 300 NMI that fast for 10 rounds straight and you’ll be all over the place. Of course in F-Class you guys take time to read the wind before each shot, so now we are back to where I started by saying making good wind calls is the key. A guy who knows his 7-6.5 PRCW or 6mm Dasher very well and can make excellent wind calls on a string, is gonna spank anyone with a bigger cartridge and bullet with much higher BC if they don’t have the same wind reading skills with their rifle. But then you add in barrel heat while shooting in 80-100 degrees, recoil, bullet jacket stressing, etc on top of that, and their chances of winning against the smaller cartridges that are more accurate in those conditions starts dwindling pretty fast.

If you must shoot the 250 A-Tip, maybe look into a 300 WSM reamer with the proper freebore. The WSM is about as big as you see anyone venturing in 30 cals these days and it can definitely win if you keep it in tune

 

[Mike TackleBerry]

I'm getting ready to try 230 Atips with retumbó. Rifle is a .300 Norma Magnum Improved (NMI) with 34" barrel 8.5 twist. Just wondering if anyone has tried something similar. I'm really interested in how this bullet performs going through the transition zone as I'm looking to reach out to close to 3000 meters. From previous bullet experience with this rifle I'm expecting to get around 3150 fps out of it
or will be looking for a node around that range

300 Norma is an excellent long-range cartridge, but you're in Heavy ELR territory. If shooting 3000 meters is something you want to pursue a 37XC or 375 Cheytac would have been a superior choice.

I'm getting ready to try 230 Atips with retumbó. Rifle is a .300 Norma Magnum Improved (NMI) with 34" barrel 8.5 twist. Just wondering if anyone has tried something similar. I'm really interested in how this bullet performs going through the transition zone as I'm looking to reach out to close to 3000 meters. From previous bullet experience with this rifle I'm expecting to get around 3150 fps out of it
or will be looking for a node around that range

Speed is only going to help you if you can control your Extreme spread.

 

[wi50]

I've shot that combo a lot. 90 gr of retumbo and 230 atip. I run 88 gr of retumbo and the 250 atip, and the 245 berger EOL. I've got a couple of electric target shotmarker systems and today I'm putting one in at 1000 yards, and another one at a mile. There's steel targets to over 4000 yards at this range, but I want the shotmarker systems too, what a fast way to gather data and compare at distance

 

[davidjoe]

I've shot that combo a lot. 90 gr of retumbo and 230 atip. I run 88 gr of retumbo and the 250 atip, and the 245 berger EOL. I've got a couple of electric target shotmarker systems and today I'm putting one in at 1000 yards, and another one at a mile. There's steel targets to over 4000 yards at this range, but I want the shotmarker systems too, what a fast way to gather data and compare at distance

I haven’t read anything from someone else who has shot all three of those bullets.

I’m very curious how you’d place them relative to each other group size potential.

For me, even if there was no wind, the 250’s take the group size. If there’s wind, they have a marked advantage.

This is assuming of course that the jackets aren’t damaged short of a blow up.

Second question, do you also find that the 245’s drift significantly more than the 230’s, just as the lower BC would sugget?

They 245’s do not have a blow up problem at all, in string fire, just as most Bergers do not. And they shoot very well, but I do not feel that a Win Mag could offer any benefit at all, if they were the only bullet choice. Instead I’d pick the much lighter 195.

 

[wi50]

That's the beauty of what I'm doing here, the shotmarker systems at distance. A guy can shoot alternating rounds, odd number shots are xx load, evens are yy load. Identical conditions, compare the data. I see some small groups on steel plates at a mile on the Internet, so these systems can be incorporated into the elr matches. The decimal point will move, maybe a few times in the real world. To many guys think they're going to hit the elk at a mile, a thousand yards, whatever, now's a chance to prove it. As for the 230, vs 250 atip, vs the 245 berger. I feel like the 245 berger is more accurate. Wind is wind, drop is drop, missing a change in conditions is the same, the margin of error between them may give an advantage. Well know more tomorrow, I have all them with to run through the 300 Norma improved today and tomorrow

 

[wjplohman]

I'm getting ready to try 230 Atips with retumbó. Rifle is a .300 Norma Magnum Improved (NMI) with 34" barrel 8.5 twist. Just wondering if anyone has tried something similar. I'm really interested in how this bullet performs going through the transition zone as I'm looking to reach out to close to 3000 meters. From previous bullet experience with this rifle I'm expecting to get around 3150 fps out of it
or will be looking for a node around that range

So I was out today and settled on a node pushing at an average of 3181. And gave a good triangle , 2 horizontal, one vertical in the middle group, seems for me a good indication. Next seating depth to see if I can tighten the groups

 

[wjplohman]

Retumbo is a good powder choice.

I’m on a personal quest to make the 250’s and to a degree, the 230’s work in string fire Fclass.

Here’s the situation with them as I see it on the 250’s and 230’s:

1) the 250’s, especially, flat trounce other 30’s in wind drift, and I just saw this again as of Sunday;

2) I shot them at over 2,850 with Retumbo from a 300 Win Mag;

3) I got two no reads when the barrel was hot even with generous HBN coating, and had to revert to the bullets I started with, but they shot SO well, better with stout Retumbo charges than h-1000, and no less than 9 inches less drift than I had with the 245 EOL’s;

4) I have eight 5R 1:8 barrels currently mounted in rotation and they will ALL blow up 250’s, if I am not exceedingly careful, and all shoot potentially better than I can with anything else, if they do not blow up;

5) I predict you won’t string fire them, but will still occasionally lose them, because of the cartridge size.


This is truly a trap, if you don’t push them hard, you won’t like the results of 230’s. If you do push them hard, you must be cognizant of fragility.

I suspect I blew up 5 in a row of 230’s last month at 600. Infuriatingly, I moved to an etarget not in use and finished out the string with the exact same bullets with ZERO no reads and an incrementally hotter barrel, leaving doubt about what was going on.

I’m having two 8.5 twist barrels finished this week and one of them is deliberately going to have 3 inches cut off the muzzle, which absolutely kills me to do because I don’t know if it will help, it will most certainly slow them down, and these are up charged for both length and 1.5” bar stock. I hate being put in that position.

If the 250’s were a prize fighter, then they would have to be described as brutally unmatched in strength but with a glass jaw.

I can’t make the 230’s rival the 250’s yet at 1,000 and I no longer believe they are immune to blow ups, so they aren’t high on my list right now.

I'm running 8.5 twist and so far no blow ups but less than 20 down the pipe above 3100

 

[davidjoe]

I shot 190 A-Tips today as well. I was perfectly happy with this target, from a .284!

 

[Steve Donlon]

I haven’t read anything from someone else who has shot all three of those bullets.

I’m very curious how you’d place them relative to each other group size potential.

For me, even if there was no wind, the 250’s take the group size. If there’s wind, they have a marked advantage.

This is assuming of course that the jackets aren’t damaged short of a blow up.

Second question, do you also find that the 245’s drift significantly more than the 230’s, just as the lower BC would sugget?

They 245’s do not have a blow up problem at all, in string fire, just as most Bergers do not. And they shoot very well, but I do not feel that a Win Mag could offer any benefit at all, if they were the only bullet choice. Instead I’d pick the much lighter 195.

Sorry if I missed your reason for putting all this effort in a 300 Win Mag. The people I shoot with moved to the 300 PRC and it seems more suited for heavy bullets with the dynamics of the case compared to the Win Mag. If it's sentimental, I like the 30-06 and like to see how much can be done with it. So no offense intended.

 

[davidjoe]

Sorry if I missed your reason for putting all this effort in a 300 Win Mag. The people I shoot with moved to the 300 PRC and it seems more suited for heavy bullets with the dynamics of the case compared to the Win Mag. If it's sentimental, I like the 30-06 and like to see how much can be done with it. So no offense intended.

I gave 300 PRC a lot of thought as well. At the time, SAUM brass limitations caused me to turn away from it. I would have fresh barrels that I wanted to pair with new brass, but it was unavailable. Lapua never made it, Peterson got large knowing it was a popular match round but passed on it and Norma stopped making it.

The saum cartridge has never been accepted by the armed forces and generally was not chosen by the shooting public often either. The 300 PRC, being so new at the time I settled on the 300 Win Mag, seemed to me to pose some of the same risks. I did not want to pick a replacement cartridge that might end up suffering the same problem.

The 300 Win Mag is older than I am and has never diminished in popularity. The Win Mag has a longer powder column than the PRC and that to me is desirable for the slowest powders and longest bullets, which was my only intended use.

The 7 PRC and 300 PRC are against the Win Mag and 7 mm Rem Mag. I believe the PRC’s both offer the heavy bullet in a custom chamber a tad less performance, but even if they offered a bit more, the certainty of being able to obtain brass kind of depends on what non-match shooters are supporting.

A last consideration is that the U..S. armed forces use the 300 Win Mag. Lapua, who makes brass for both, knows the prestige of acceptance of a cartridge for this purpose. Its own 338 Lapua Mag is one of the newest additions to this very limited line up. It amounts to immortality, and basically if you have designs on arms contracts, and Nammo certainly does, making it is not optional.

 

[Steve Donlon]

I gave 300 PRC a lot of thought as well. At the time, SAUM brass limitations caused me to turn away from it. I would have fresh barrels that I wanted to pair with new brass, but it was unavailable. Lapua never made it, Peterson got large knowing it was a popular match round but passed on it and Norma stopped making it.

The saum cartridge has never been accepted by the armed forces and generally was not chosen by the shooting public often either. The 300 PRC, being so new at the time I settled on the 300 Win Mag, seemed to me to pose some of the same risks. I did not want to pick a replacement cartridge that might end up suffering the same problem.

The 300 Win Mag is older than I am and has never diminished in popularity. The Win Mag has a longer powder column than the PRC and that to me is desirable for the slowest powders and longest bullets, which was my only intended use.

The 7 PRC and 300 PRC are against the Win Mag and 7 mm Rem Mag. I believe the PRC’s both offer the heavy bullet in a custom chamber a tad less performance, but even if they offered a bit more, the certainty of being able to obtain brass kind of depends on what non-match shooters are supporting.

A last consideration is that the U..S. armed forces use the 300 Win Mag. Lapua, who makes brass for both, knows the prestige of acceptance of a cartridge for this purpose. Its own 338 Lapua Mag is one of the newest additions to this very limited line up. It amounts to immortality, and basically if you have designs on arms contracts, and Nammo certainly does, making it is not optional.

I get it. The 300 Win Mag has a lot of history. I have a Bartien gain twist target barrel in one on my 6.5 Creedmoor target rifles It's only a 8-71/2 but it gently puts pressure on the rifling to engage. Kind of like throwing a football and you put more pressure on your little fingers to control the spin. At least that's one way to view it. This barrel is very accurate and I don't want to wear it out to soon. Maybe a gain twist barrel will help your blow ups. Just like the reasons for a 3 groove barrel, some think it's great and some don't buy it. I do from what I have seen. But I don't compete with a group of other people. I shoot 300. 500,800 then 1000 every week with a friend. So I understand the pressure of competing how much effort it takes, so good luck with the 300 Win Mag.