New 300 Norma Mag build Twist rate question

[Tactically_Advantangeous]

Hey Gurus,

Not the sharpest tool in the shed when it comes to intricate knowledge of twist rates etc, But I splurged a little, waited a while and got myself a .300 Norma Mag. Only Thing is, it's a 1:9 26" Barrell and I've been waiting about a year for this, so now that I've been doing some more research, I'm finding a lot of guys are running the 1:8 twist w/ 230g Berger. Am I shafted on utilizing this round and narrowing myself to say a 215g Berger? OR anyone have good success with their 1:9 Twist? OR recommendations on what kinda projectile I should focus on for my load development. Any insight and opinions would be appreciated. Thanks.

The Dude

 

[WeiserBucks]

9 twist will work great. I used 215s, 225s and 230s in mine, just settle on whichever shoots the best in your particular rifle.

 

[MOUNTIC]

1/9 is excellent for the 230 in your rifle. I wouldn't want the 8 personally.

 

[Tactically_Advantangeous]

Ah ok, this is already putting me at ease, I thought for sure I was going to get cornered into on a certain projectile without even getting into load development. Thanks for the replies thus far.

 

[generalzip]

I am building one now and went 8. No clue why anyone would buy anything other than an 8 with the release of the 230 and 250 A tip basically destined for the 300NM. I've found in general faster twists only help you. As long as you aren't blowing up bullets a faster twist will get you a higher BC allowing you to run at lower velocity and pressure for the same long range performance. However if you only plan to shoot a 230 berger the 1/9 will work absolutely fine.

 

[Tactically_Advantangeous]

release of the 230 and 250 A tip basically destined for the 300NM.

Thanks Generalzip for you input, I took a look at those aluminum tipped rounds that Hornady are putting out. Seems like there is definite potential. What I would be curious to know if a 1:9 would still be able to stabilize up to the 250g out to at least 1000yards. I guess if it isn't I just won't have that luxury to be able to use the 250g in the future. I'm sure, I'll be content with just the 230, but would be nice to do load development on the 250 and see the terminal ballistics on those. I'll take solace knowing that if indeed, that's the case. In about 1000 rounds I'll have to switch it out and go with a 1:8. lol so won't have to wait to long.

 

[generalzip]

If you’re a shooting to only 1000 yards the 250 offers no advantage. I doubt a 9’twist would stabilize a 250 of give full BC of the bullet at a mile. That said nobody has them yet so buy a box give them a try and let us know!!! If it were me I’d shoot your barrel out with 230 Berger’s then switch to a 1-8 and 250 a tips after that

 

[Gilly]

I don’t know why anyone would want to shoot a 250 anyway especially inside a mile. Outside of that maybe worth it maybe not. I run the 215 Berger to 2000 yards and 230 smk the same and couldn’t be happier. Out to 1600 the 215 Berger is just awesome! Silly accurate and less wind and drop than 230 Berger. I’m running a 9 twist 28” barrel.

Back to the 250, you’re likely gonna be down around 2700 maybe 2800 if you really push it with 26-28” barrel at least that’s my estimates. I would shave 200 FPS of my 230 load as a guess so that’s 2750 from a 28” tube. You might as well go to a 338 at that point with a 300 Berger, or I would, but that’s overkill inside 1000 too. Or if you’re after BC for the money go with a 198 flatline at least you keep speed and cost is relatively close.

 

[MOUNTIC]

If ONLY shooting the 250 A-Tips thats one thing as general zip indicated. But unless your shooting ELR, I see no reason to shoot those pills inside a mile really.

A 230 Berger at 2900 fps at 0' altitude and 0 degree temps is still fully stable out of a 9. And that's more extreme conditions then I will ever be shooting at. Add in any altitude or temp and see those stability numbers jump.

Even with a 10 twist its fully stabilize with 230s in a lot of altitudes and conditions. (At least where I'm at)

If you shoot the 212s, 215s, 225s, 230s stick with 9.

Just my opinion of course.

 

[Gilly]

After plugging some numbers in to AB at 2750 the 250 Atip has no advantage over my current 230 smk load at 2950. Almost identical supersonic range and wind drift is within .1 mil at 2000 yards, 230 is flatter. The 250 has roughly 100 foot pounds of energy more is all at that distance. The one that may be worth it is the 230 ATip if I can match my current velocity the slight bc increase may have some side by side advantage but it’s also about $0.30 per bullet more expensive than the SMK. I think I’ll stay where I’m at.

 

[generalzip]

I don’t know why anyone would want to shoot a 250 anyway especially inside a mile. Outside of that maybe worth it maybe not. I run the 215 Berger to 2000 yards and 230 smk the same and couldn’t be happier. Out to 1600 the 215 Berger is just awesome! Silly accurate and less wind and drop than 230 Berger. I’m running a 9 twist 28” barrel.

Back to the 250, you’re likely gonna be down around 2700 maybe 2800 if you really push it with 26-28” barrel at least that’s my estimates. I would shave 200 FPS of my 230 load as a guess so that’s 2750 from a 28” tube. You might as well go to a 338 at that point with a 300 Berger, or I would, but that’s overkill inside 1000 too. Or if you’re after BC for the money go with a 198 flatline at least you keep speed and cost is relatively close.

I think the appeal of the 250 A tip is its a cup and core bullet that is much easier to tune than a solid. Early reports show they are easy to tune, extremely accurate, and have crazy high BCs. I doubt you'd lose quite that much going from 230 to 250 grain bullets. I expect to be around 2800-2850 with a 250 in a 28" barrel. I have friends shooting 230s over 3000 without issues. The reason folks want the 250 a -tip inside a mile is the higher BC will give you less wind drift and thus higher first round hit probability. VS a 230 hybrid its probably only a couple tenth but guys are chasing everything they can in this game. I'm waiting for the 500 I ordered to come in and can report back with how they shoot.

 

[generalzip]

After plugging some numbers in to AB at 2750 the 250 Atip has no advantage over my current 230 smk load at 2950. Almost identical supersonic range and wind drift is within .1 mil at 2000 yards, 230 is flatter. The 250 has roughly 100 foot pounds of energy more is all at that distance. The one that may be worth it is the 230 ATip if I can match my current velocity the slight bc increase may have some side by side advantage but it’s also about $0.30 per bullet more expensive than the SMK. I think I’ll stay where I’m at.

What velocities did you use? I'd compare 2850 with a 250 to 2950-3000 with a 230.

 

[generalzip]

A 215 only gains about 70 FPS over a 230 from what I’ve seen. So I wouldn’t expect more than 100 FPS between a 230 and 250 grain bullet. Which leads me to believe 2900 should be fairly easy to obtain with a 26-28” barrel in the 300NM

 

[Lowlight]

8 don't work in the Norma, too much speed and too fast a twist

You don't want to go over 9 and even though at my last Gunsite outing 5 of us were shooting a 300NM and at 2k we see the fast twist rifles not do nearly as good as the 10s and 9s

You cannot overspin them especially with Berger bullets the jackets are too thin to handle it

Why does everyone think the Army went quiet on the 300NM because they went 8 and it doesn't work right.

The entire shooting world knows a 1-10 works with a heavy 30 cal if you want to want to shoot solids or super heavy, no more than 9s.

My 25" Brux Barrel, 1-10 pushes 230s at 2960fps and it's a hammer, I did have rounds that went 2990 but were too hot for AZ.

 

[Tactically_Advantangeous]

Awesome input guys, really appreciate it, especially from the ones that have already gone and done it with this caliber.

I run the 215 Berger to 2000 yards and 230 smk the same and couldn’t be happier. Out to 1600 the 215 Berger is just awesome! Silly accurate and less wind and drop than 230 Berger. I’m running a 9 twist 28” barrel.

Oh that's awesome to hear. I had a long conversation today and went with the 1:9, so now I feel good about it. Yea can't wait to try those 215's and the 230 smk and even the 225's as well. Thanks for your input.

If you shoot the 212s, 215s, 225s, 230s stick with 9.

Yep, can't wait to nerd out on each of those to do some load development on them. Appreciate the input.

8 don't work in the Norma, too much speed and too fast a twist

You don't want to go over 9 and even though at my last Gunsite outing 5 of us were shooting a 300NM and at 2k we see the fast twist rifles not do nearly as good as the 10s and 9s

You cannot overspin them especially with Berger bullets the jackets are too thin to handle it

Why does everyone think the Army went quiet on the 300NM because they went 8 and it doesn't work right.

The entire shooting world knows a 1-10 works with a heavy 30 cal if you want to want to shoot solids or super heavy, no more than 9s.

My 25" Brux Barrel, 1-10 pushes 230s at 2960fps and it's a hammer, I did have rounds that went 2990 but were too hot for AZ.

Thanks Lowlight, good input, and the research I've been seeing on some of the other long range forum sites kinda elude to that as well. Geez, nice group. Appreciate it.

 

[theLBC]

in case it helps

Twist Rate Stability Calculator

Our newly updated Twist Rate Stability Calculator not only tells you what your SG is, but it also lets you know if you are reaching your optimized BC.

bergerbullets.com

 

[Ledzep]

230 vs. 250 A-tip is a pretty close battle. Wind is almost identical, supersonic range is almost identical. The trade off is elevation (230 is flatter-- to a point, but within 'realistic' range) vs. impact spotting (250 is better).

Apples to oranges but the 300 PRC load data shows ~150 fps difference between the two. I'd imagine 2750-2800 is possible with the 250 in the Norma. 2900-3000 with the 230.

If you live at elevation and don't shoot below freezing, the 250's will probably work in a 9 twist, also. In some worst case scenarios you might run into issues (alaskan coast in the winter), but I doubt most of us will.

 

[generalzip]

8 don't work in the Norma, too much speed and too fast a twist

You don't want to go over 9 and even though at my last Gunsite outing 5 of us were shooting a 300NM and at 2k we see the fast twist rifles not do nearly as good as the 10s and 9s

You cannot overspin them especially with Berger bullets the jackets are too thin to handle it

Why does everyone think the Army went quiet on the 300NM because they went 8 and it doesn't work right.

The entire shooting world knows a 1-10 works with a heavy 30 cal if you want to want to shoot solids or super heavy, no more than 9s.

My 25" Brux Barrel, 1-10 pushes 230s at 2960fps and it's a hammer, I did have rounds that went 2990 but were too hot for AZ.

View attachment 7109546

Frank was anyone shooting 250 A-tips in the 8 twist? My understanding is they are pretty much unobtanium still. Hornadys own website recommends a 8.5 twist so I can't imagine a 8 twist wouldn't work

 

[generalzip]

230 vs. 250 A-tip is a pretty close battle. Wind is almost identical, supersonic range is almost identical. The trade off is elevation (230 is flatter-- to a point, but within 'realistic' range) vs. impact spotting (250 is better).

Apples to oranges but the 300 PRC load data shows ~150 fps difference between the two. I'd imagine 2750-2800 is possible with the 250 in the Norma. 2900-3000 with the 230.

If you live at elevation and don't shoot below freezing, the 250's will probably work in a 9 twist, also. In some worst case scenarios you might run into issues (alaskan coast in the winter), but I doubt most of us will.

2900 is pretty slow with a 230 in this caliber. Try RE33 if you can't get higher than that. 3000+ is pretty common with 27-28" barrels. Shit Frank is doing 2960 with a short 25". 2750 is near 300 win mag speeds. Also I'd never trust hornady's max load data I've always found it to be way way on the conservative side and not uncommon for me to get 50-100 fps more than their book max without pressure.

 

[Gilly]

What velocities did you use? I'd compare 2850 with a 250 to 2950-3000 with a 230.

2750 on 250 vs 2950 I currently run on my 230 smk load. No one has hands on 250 yet I’ve seen so thanks for telling me I’m wrong with no data to back it up. I usually go off 100 FPS change per 10 grain (20 grains = 200 FPS) bullet as a rule until proven differently by data and normally not too far off. I’m at 3075 with my 215 Berger so 125 on 15 grains, my rule of thumb is close on this gap.

Even IF you get 2800 or 2850 MAX that 50-100 FPS isn’t gonna change my mind for the hassle and cost for .2 mil advantage wind.

 

[generalzip]

2750 on 250 vs 2950 I currently run on my 230 smk load. No one has hands on 250 yet I’ve seen so thanks for telling me I’m wrong with no data to back it up. I usually go off 100 FPS change per 10 grain (20 grains = 200 FPS) bullet as a rule until proven differently by data and normally not too far off. I’m at 3075 with my 215 Berger so 125 on 15 grains, my rule of thumb is close on this gap.

Even IF you get 2800 or 2850 MAX that 50-100 FPS isn’t gonna change my mind for the hassle and cost for .2 mil advantage wind.

Relax big guy. Never said you were wrong. I asked what velocities you used then gave you a friendly suggestion on what numbers to used based on published load data from bullet and powder manufacturers between a 215 and 230 grain bullet of about 70 fps. Each barrel, barrel, chamber, and brass combo will behave differently. Generally I've found the heavier for caliber you go, the less impact you see per grain of bullet. For example look at a 140 vs 147 ELD in 6.5. That's quite heavy for caliber and guys shoot them essentially the same velocity maybe 10-20 fps difference. I would be very surprised if you couldn't get near 2900 with a 250 in a 300 NM with a proper freebore.

 

[Ledzep]

Also I'd never trust hornady's max load data I've always found it to be way way on the conservative side and not uncommon for me to get 50-100 fps more than their book max without pressure.

Without visible overpressure signs or within SAAMI/CIP pressure?

My experience is that their max loads are right at or just below SAAMI max in most cases. Obviously different bullets, case brands, primers, powder lots, etc.. can all skew results, but most of the time you see "pressure signs" (should more correctly be "Overpressure signs" in the upper 60's to mid 70's ksi range so there's a window in there where you're running hotter than SAAMI and don't know it. Typically it's not the end of the world to run a little warm-- lots of people out there doing it, but it's worth knowing.

 

[generalzip]

Without visible overpressure signs or within SAAMI/CIP pressure?

My experience is that their max loads are right at or just below SAAMI max in most cases. Obviously different bullets, case brands, primers, powder lots, etc.. can all skew results, but most of the time you see "pressure signs" (should more correctly be "Overpressure signs" in the upper 60's to mid 70's ksi range so there's a window in there where you're running hotter than SAAMI and don't know it. Typically it's not the end of the world to run a little warm-- lots of people out there doing it, but it's worth knowing.

Without pressure signs. I don’t have a lab with strain gauges I bring to the range haha. My handloads show less pressure signs than most factory ammo including hornady. Guess it’s just my powder/brass combos that I’m using.

 

[bodhisafa]

Good thread was about to start one myself. As a side note, any action that is recommended for the 300 norma? Looking for single shot

 

[Tactically_Advantangeous]

2950 I currently run on my 230 smk load.

Hey Gilly,
Curious to know what's some perk you've found shooting with the 230 SMK over the Berger's? It sounds like you've shot both, any thing of real note about the difference other than the terminal ballistic of the round? I'll most likely add in those 230 SMK in my load development plan as well, so was just curious. Appreciate it.

any action that is recommended for the 300 norma? Looking for single shot

Hey Bodhisafa, can't really attest to any one action out there personally, but hopefully others would be able to shed light for you. I ended up going with custom defiance one, which is the one thing that took almost year and half to get.

 

[bjay]

I probably built 5-6 300nm mostly all improved and tried majority of them known pills.from 198 to 240smk from 9 10 8.5 and gain twist..9 twist IMO is the most forgiving twist specially if you setting rig to shoot 215 -230 smk and hybrids .now if your planing to build it for the 250 or strictly new 230smk a little faster would be good...but there's no need to go crazy fast on twist...
Why would you pick 250 over 230s? Can you pushed them fast enough to take advantage of her BC?
Are you planing tp mag load them? 230smk is already barely fit on Cip when its loaded properly where bearing slightly above shoulder

 

[kthomas]

Good thread was about to start one myself. As a side note, any action that is recommended for the 300 norma? Looking for single shot

I had Defiance build me a DLC'ed/IonBonded action for my .300NM - it's been great, no regrets. They can build you a single shot if that's what you want, lots of different options available with Defiance.

 

[Scott.Neidrick]

Hey All, great thread! I just came across this thread and has some data to provide that may help someone. I built a 30” 1-8 twist Bart 5R 300NM. Purpose built for 250 ATIPS. Pushing at 3030 FPS (not a hot load-no pressure signs). The ATIPS are exploding. Ran 300 rounds with no issues but at a modest shot string rate. During a competition, putting 10 down the tube at a time, some came apart (likely extra heat etc). I’m switching to the 245 Bergers to see if they will hold up. I will say the ATIPS were very good when they actually worked. I’ve taken it out to 2,700 yards with great consistency. Just some food for thought to help the next guy! Thanks!

 

[NoLegs24]

Oh Hornady, how comical its become. Funny, Bergers keeping trucking at similar speeds in same twist, while Hornady (yes, talking about you too ATIPs) keep blowing up. Modern day Houdini.

It's become the norm at the NF ELR Match. Some (even sponsored shooters) can't believe it. But we chuckle and tell them its an on going ordeal.

One guy in our squad had like a 60% + failure with 153gr ATIPS in his 6.5PRC. I joked and told him if it landed in the vicinity of the target, consider that a win.

@hic28 lol...

 

[MOUNTIC]

3010 fps with 230atips in a 10 twist NM seem to do well to 2640 yards. I don't think I personally would go faster then a 9. But yet the new win tac AX barrels are all 8. Didn't know that til it showed up. Not sure my plan with it yet.

 

[Scott.Neidrick]

I was at the NF challenge when this was happening- word spread pretty quick. The ATIPs were the last thing on the prize table after 200 people picked. I called Hornady this week and spoke to a technician- he said he was unaware of this issue and had only recently heard about it on the 147s…I inquired some more but was basically given the ‘I’ve not heard about this is’. I let him know that word is spreading quickly and that I recommend they fix this to keep in front of the problem..we shall see

 

[hic28]

I was at the NF challenge when this was happening- word spread pretty quick. The ATIPs were the last thing on the prize table after 200 people picked. I called Hornady this week and spoke to a technician- he said he was unaware of this issue and had only recently heard about it on the 147s…I inquired some more but was basically given the ‘I’ve not heard about this is’. I let him know that word is spreading quickly and that I recommend they fix this to keep in front of the problem..we shall see

They are so full of shit. They have known about the 147 for years at this point. Fuck them.

 

[NoLegs24]

I was at the NF challenge when this was happening- word spread pretty quick. The ATIPs were the last thing on the prize table after 200 people picked. I called Hornady this week and spoke to a technician- he said he was unaware of this issue and had only recently heard about it on the 147s…I inquired some more but was basically given the ‘I’ve not heard about this is’. I let him know that word is spreading quickly and that I recommend they fix this to keep in front of the problem..we shall see

Hahahahaha. Classic Hornady.

They’re just reading from a TelePrompTer at this point…

 

[BCX]

I called them in mid 2019 about the 147 blowing up. Funny.... they are just hearing about it. Rough throats and heat love to eat Hornady bullets lol.

 

[Steel head]

They are so full of shit. They have known about the 147 for years at this point. Fuck them.

147’s for at least two years
My first 180eldms were quite excellent, ran out and got a new lot and all of the sudden I get a 40-45% poof rate.
190 ATip was about 8%
Buddy recently had 300 ATips blow
Now I’m having 130eldms blow up.

Hornandy turned me from a fan boy to skeptic in one year.

 

[Shoots 700's]

My barrel that just arrived is a 1-9 Bartlein

 

[Cerebrum]

Never heard of 250 hornady a-tips blowing up. used by a lot of people here in EU without issues in 1:8 barrels. Loads are too hot?

 

[Scott.Neidrick]

Nope- the more research I’m doing, I think I’m finding that Hornady recently had something happen during their manufacturing process with the jackets (thinner than previous). I ran 250 rounds perfectly fine, and now they are shredding. Other people are mentioning the same situation across different calibers too- especially recently. When you get. A new lot of bullets, let me know if you are encountering the issue- specifically after about 5-10 shots of heating up the barrel

 

[LRresearch]

Oh Hornady, how comical its become. Funny, Bergers keeping trucking at similar speeds in same twist, while Hornady (yes, talking about you too ATIPs) keep blowing up. Modern day Houdini.

It's become the norm at the NF ELR Match. Some (even sponsored shooters) can't believe it. But we chuckle and tell them its an on going ordeal.

One guy in our squad had like a 60% + failure with 153gr ATIPS in his 6.5PRC. I joked and told him if it landed in the vicinity of the target, consider that a win.

@hic28 lol...

Exactly my experience this weekend after breaking in a new 28” Bart 5R 6.5 PRC with the 153gr Atips. Very frustrating trying to sight a new scope in when you shoot once and there are 5 marks on the target…thanks for confirming

 

[Scott.Neidrick]

@LRresearch try the 153.5 Berger Long Range Hybrid Target - Berger uses thicker jackets for their target bullets. I had the same issue with my 6.5 PRC and ATIPs, but the 153.5 Bergers are running fantastic. Enjoy!

 

[Cerebrum]

I am running 250gr a-tip @ 3000fps in a 31 inch 1:8 twist no problem. No bullets blowing up.

 

[Scott.Neidrick]

What barrel groove? I have a Bart 5R. Also, have you fired a string of 10? I.e after the chamber is hot? Mine start exploding after about 4-6 shots.

 

[country888]

So I know it's a old thread, is anyone else still having problems with the 230s Atips blowing up or coming apart?

 

[1791PrecisionArmory]

So I know it's a old thread, is anyone else still having problems with the 230s Atips blowing up or coming apart?

I’d like to know too.

 

[Hawk in WY]

The 147 eld-m were coming apart in my eight twist 6.5 CM last year which was the last time I shot them. Not blowing up but jacket separation for sure.

 

[country888]

The 147 eld-m were coming apart in my eight twist 6.5 CM last year which was the last time I shot them. Not blowing up but jacket separation for sure.

We was referring to the 230gn Atip out of a 300 norma magnum. Thanks for the info on the 147gn eldm from your creed though.

 

[Scott.Neidrick]

I have no personal experience with the 230 ATIPs but based on the 250s and my other experiences with 153 ATIPs in 6.5 PRC- I’d expect the same negative results. ATIPs just have a thin jacket and have tough time with high RPMs- I recommend the Berger 220 LRHT if you were considering the 230 ATIPs. I had great success with the 220 LRHT in my 300 Norma at over 3200 FPS. Not exactly the info you wanted but may be helpful

 

[robb_va]

I have no personal experience with the 230 ATIPs but based on the 250s and my other experiences with 153 ATIPs in 6.5 PRC- I’d expect the same negative results. ATIPs just have a thin jacket and have tough time with high RPMs- I recommend the Berger 220 LRHT if you were considering the 230 ATIPs. I had great success with the 220 LRHT in my 300 Norma at over 3200 FPS. Not exactly the info you wanted but may be helpful

Did you have 250 ATIPs that separated? If so, what was MV and twist? I'm just beginning to use them in a 27 inch 8 twist.

 

[Shoots 700's]

Wondering what a respectable sd would be for 300 Norma. I am just starting load development for this gun with 25 rounds down the barrel.

With 215 Berger over 87.5 of N570 I’m getting 3071 fps and an sd on 8.3. Planning on shooting this load or 230 hybrids if i can locate them out to 2200.

I know its early but the sd’s look promising and the accuracy is under .5 moa so far.

 

[Scott.Neidrick]

Did you have 250 ATIPs that separated? If so, what was MV and twist? I'm just beginning to use them in a 27 inch 8 twist.

Yes I did. 1:8 Bartlein 5R 30" 3030fps - separated after 4-5 shots. You may have good luck, but the Norma is pushing the RPM - add in a hot day / multiple shots, and you may see the same effect. Recommend switching to Berger and having high confidence.