280 AI or .270

[Paul B.]

"Even with the extra case capacity and higher pressures allowed in .280 AI (versus standard .280), you're still lucky to be able to hit 2,600 fps with a 175 gr bullet."

Guess nobody told my 24" barreled .280 Rem. that. I get 2650 FPS using 53.0 gr. of WMR powder. (Cauition: max load. Powder also discontinued about 10 years ago ) Bullet was the 175 gr, Hornady Interlock.
FWIW the latest Nosler manual show about seven loads doing velocites in the 2700+ range and all velocities 2600 or higher. Granted, thy used a 26" barrel but at least half of those loads were high enough that 2600 from a 24" barrel would be more than feasable. Come to think of it, if those loads are to SAAMI standards, then surpassing 2600 FPS might not be all that difficult even with a 2" barrel. Sorry. I'm not cutting the barrel shorter on my rifle to try and prove the point.
Paul B.

 

[Creek Henry]

260 AI

Anyway, for heavier bullets go with the bigger caliber. Lighter is faster and modern bullets can do more with less weight so a few grams lighter should not be a handicap in the 21st century.

 

[HiBC]

I consider my .257 AI a little brother to the .270.I load 115 gr Ballistic tips,BC .450,to 3050.Grreat field performance,I am very happy with it.I have used it 20 yrs.Its a 1 in 10 twist,like most .270 s.

I do not need more range.Getting closer is a better idea,IMO.

However,if you take that exact same cartridge,and neck it up to 6.5,it is a "260 AAR'.

With that,the twist will become a 1 in 8 or 9,and a fine bunch of heavier ,better BC 6.5 bullets become available.

Same with the .270 vs 7 mm argument.Had the .270 been introduced with a 1 in 8 twist,bullet mfgrs would offer 150 to 165 gr or so bullets.Yes,I know,150 gr .270 bullets are available,but,twist relates to length,and the 150 gr bullets are semi-blunt.

IMO,a 160 gr 7mm bullet flies well and is efficient per the bore dia.


In the end,for the most part,its all just "hissing in the wind"

The person holding the rifle matters far more than which caliber.

 

[taylorce1]

Same with the .270 vs 7 mm argument.Had the .270 been introduced with a 1 in 8 twist,bullet mfgrs would offer 150 to 165 gr or so bullets.Yes,I know,150 gr .270 bullets are available,but,twist relates to length,and the 150 gr bullets are semi-blunt.

Yep all them Berger VLD, Hornady SST & Interbonds, Sierra GK, and Nosler's BT bullets are way too blunt. I mean the 150 Nosler ballistic tip is so blunt it has a higher BC rating and is .050" longer than the 150 grain 7mm ballistic tip. I'm sure glad those blunt bullets shoot well out of a lazy 1:10 twist .270 Win.

 

[HiBC]

OK,Taylorforce,I concede I have not been keeping up with the modern bullets for the .270.Agreed,things have improved

Blunt may not have been the best word.

Yet ,on the Berger site,for a 150 gr hunting vld,good in a 10 in twist,the BC is a very respectable 531 in .277 cal

In a .284 bullet,a 1 in 9 twist is good for a 180 gr 7mm bullet,with a BC of .659

So,once again,its not bore diameter,but standard rifling twist that gives a minor long distance edge to 7mm bore dia.

And,once again,its all hissing in the wind,as both are excellent,and the shooter makes more difference.

I firmly believe the .270 is one of the best choices a hunter could make.

 

[natman]

280 AI or .270?

I've found myself with 2 rifles that are poised to go with me on a western hunt this fall and I have no ammo for them.

If ammo availability is your concern, why are you even considering a wildcat like the 280AI?

Get the 270.

 

[.300 Weatherby Mag]

If ammo availability is your concern, why are you even considering a wildcat like the 280AI?

The 280AI is a now a factory cartridge.. It was registered with SAAMI in 2007...

I know news travels slow but its been a standardized cartridge for six years!!!

The Rem mag does stomp the Ackley.

Real world experience with both will show that you can get darn close to 7mm Rem Mag performance with a 280AI... Without a belted case and with less recoil... 7mm Rem Mags kick out of proportion to their size IMO... I've never been impressed with the 7mm Rem Mag as you can get more speed with every bullet weight with a 7mm Weatherby Magnum... And the 7mm Weatherby also fits in the same length action as the Rem Mag.. The 7mm Remington works but there are better options...

 

[taylorce1]

Real world experience with both will show that you can get darn close to 7mm Rem Mag performance with a 280AI...

My point was the .280 AI is loaded to 62K psi and the 7mm RM is loaded around 55K psi. If you load the 7mm RM up to 62K psi it will stomp all over the .280 AI. My other point is that when looking at data we should all go "Hmmm" when the .280 AI starts beating a rifle case with significantly more powder capacity. All I'm saying is I really think Nosler is padding the .280 AI data to sell rifles and ammunition.

I have a Hogdon annual reloading magazine and the brand new Lee manual and neither have the .280 AI approaching the speeds Nosler does running pressures in the 60-62K psi range. My older Sierra and Nosler 5th edition which don't have pressure listed don't list anything close to the new Nosler manual for speed but they mirror the Hogdon and Lee data. Nosler started cranking up the speeds in the 6th and 7th editions of their manuals but there is no listing for pressures. That nice little disclaimer in their book absolves them from liability if something blows up while pursuing their max book loads.

I reload for the .280 Rem and .270 Win so I'm pretty intimate with both rounds. I've sold off or rebarreled all of my 7mm RM because I don't like the cartridge. I've ran as well the 7mm-08 in both pistol and rifle and the .280 GNR as a pistol. All I can say is that a simple shoulder change isn't going to increase the capabilities of the .280 enough to make it perform like a 7mm RM without being over 62K psi.

HiBC, a lot has changed in the world of .277 bullets over the last couple of years but it has been a very, very long time since Nosler has brought out the BT. Plus the only bullet Nosler has ever listed as a semi-spitzer has been the 160 grain Nosler Partition. Nosler is to introduce sometime in the near future a new Accubond LR that has a .625 BC rating for a 150 grain .270 that works in a 1:10 twist of the standard rifle. Matrix bullets offers a 165 grain VLD that stabilizes in a 1:10 twist barrel that give a BC rating of .738 for the .270.

To: marshal@matrixballistics.com
Subject: twist rate
Date: Fri, 4 Mar 2011 11:39:33 -0500

Hi,

Will your heavy .277 VLDs stabilize in a 1:10 twist barrel?



__________________________________________________ __________________________________________________ __________________


Hi,

The 165 gr should work fine, the 175 is doubtful.

Thanks,
Marshal

 

[Picher]

The newer bullets available, like Barnes, Hornady GMX, and the old tried and true Nosler Partitions make various cartridge killing ability differences much less than in the past. For instance, I shoot Hornady GMX bullets out of my .270 Win, 24" barreled rifle over 3,200 fps, thanks to Reloder 22 and 60+ grains with CCI magnum primers.

Bullets that expand quickly, but hold together well are deadly in any of the cartridges discussed. Heavier bullets are not as necessary and for long range shooting, flatness of trajectory means more to me when hunting whitetail deer along long, straight woods roads. Shooting 180 grain bullets or heavier out of a .280 AI may result in less favorable point-blank range situation.

My .270 load will stay within 3" of POA out to 330 yards and holdover beyond that is minimal. I keep shots under 450 yards, preferring under 400 yds.

That's my opinion, for what it's worth.

 

[old roper]

My wifes 280AI was completed 2006 and I used Nosler manual and their data was pretty close and my 280AI was completed and I used Nosler manual #6 and their data using 160 gr AB with IMR-7828 was spot on in velocity.

As to the 7mag vs 280AI. You can load the 7mag any way you want the different is case capacity and the amount of powder the 7mag uses so it should be faster. You got a case using 10gr more powder and how much more to reach max SAAMI pressure. In my 280AI I use less than 60grs of powder with 160gr AB @ 3060fps and I'm not to max powder data.

Big difference is the choices one makes on what they want to shoot or build.

Taylor you post on the Nosler site if you think Nosler is padding their data why don't you bring it up on that site their running that site?

 

[reynolds357]

.300 WBY. I dont see the 7WBY as being all that wonderful. My favorite Eastern hunting 7 is the 7WSM.
My 7 b.r. gun is a .284Win.
My western hunting 7 is the 7 RUM.
I use my 7-30 Waters for a brush rifle.
As far as felt recoil, I dont think I can tell you any real difference between the .280 A.I., 7 Rem, and 7 WBY. To me to feel a recoil difference I have to go down to .284 and 7-08,

 

[taylorce1]

Taylor you post on the Nosler site if you think Nosler is padding their data why don't you bring it up on that site their running that site?

I asked Nosler4 by PM to post pressure data and the reply I got was it was safe in their test equipment to shoot. If you go look at the velocities posted on Nosler ammunition they are loading it at least 100 fps slower than max load listed in their manual as well.

I had a buddy run QL for me and while I don't think QL has all the answers it even says that the .280 AI is a little hot at the speeds Nosler is publishing.

Cartridge : .280 Ack Imp
Bullet : .284, 140, Nosler Accubond 59992
Useable Case Capaci: 67.311 grain H2O = 4.370 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length : 24.5 inch = 622.3 mm
Powder : IMR 4831

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 76 45.20 2375 1741 27349 8616 92.8 1.619
-18.0 78 46.33 2432 1826 29074 8873 93.9 1.582
-16.0 80 47.46 2489 1912 30901 9121 94.9 1.545
-14.0 82 48.59 2545 2000 32837 9359 95.8 1.510
-12.0 84 49.72 2602 2089 34887 9585 96.6 1.475
-10.0 86 50.85 2658 2181 37057 9798 97.4 1.441
-08.0 87 51.98 2714 2273 39355 9999 98.1 1.400
-06.0 89 53.11 2769 2367 41787 10185 98.6 1.360
-04.0 91 54.24 2825 2463 44363 10356 99.1 1.322
-02.0 93 55.37 2880 2559 47089 10512 99.5 1.286
+00.0 95 56.50 2934 2657 49976 10651 99.7 1.251 ! Near Maximum !
+02.0 97 57.63 2988 2756 53034 10773 99.9 1.217 ! Near Maximum !
+04.0 99 58.76 3041 2855 56274 10877 100.0 1.184 ! Near Maximum !
+06.0 101 59.89 3094 2955 59708 10967 100.0 1.153 !DANGEROUS LOAD-DO NOT USE!
+08.0 103 61.02 3147 3056 63351 11053 100.0 1.122 !DANGEROUS LOAD-DO NOT USE!
+10.0 105 62.15 3199 3158 67216 11136 100.0 1.093 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 5% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 5% relative to nominal value:
+Ba 95 56.50 3002 2781 54842 10460 100.0 1.201 ! Near Maximum !
Data for burning rate decreased by 5% relative to nominal value:
-Ba 95 56.50 2853 2512 45158 10698 98.3 1.309

I don't think QL is as good a pressure testing equipment but IME it has been close.

 

[Kachok]

I am not cherry picking anything those are the fastest loads listed in any of my manuals. If you want a full case on both let's compare again with fastest loads in 150gr.
150gr 270 Win 61.5gr MagPro 2913fps 101% compressed load
150gr 280 AI 63gr IMR7828 3107fps 103% compressed load
To be completely fair Nosler used a 26" barrel for the 280AI and a 24"' for the 270 so subtract 50-60fps and it only holds an aprox 140fps advantage in 150gr in the same length barrel, nothing earth shattering but certainly noticeable, 140fps is about all that separates my 7mm-08 from a 280 Rem in common bullet weights.

 

[wet]

I have a wetherby vanguard 270 and a rem.700 280. love them both, they are interchangeable and both will kill anything in this country. As said before 270 rounds can be found in any store that sells amo. I reload like you and there is more bullet choice, not that you need it. I don't think you can make A wrong choice.

 

[natman]

If ammo availability is your concern, why are you even considering a wildcat like the 280AI?

The 280AI is a now a factory cartridge.. It was registered with SAAMI in 2007...

I know news travels slow but its been a standardized cartridge for six years!!!

I stand corrected on the use of the word "wildcat". I should have said "offbeat, only available as semicustom, not loaded by any of the major manufacturers" instead. (No, I don't count Nosler and Norma as majors).

So now that that nit has been picked, SAAMI standardization or not ammo availability of 280AI is going to be tough, certainly not compared to 270!

So I repeat:

If ammo availability is your concern, why are you even considering an wildcat offbeat cartridge like the 280AI?

 

[.300 Weatherby Mag]

.300 WBY. I dont see the 7WBY as being all that wonderful. My favorite Eastern hunting 7 is the 7WSM.
My 7 b.r. gun is a .284Win.
My western hunting 7 is the 7 RUM.
I use my 7-30 Waters for a brush rifle.
As far as felt recoil, I dont think I can tell you any real difference between the .280 A.I., 7 Rem, and 7 WBY. To me to feel a recoil difference I have to go down to .284 and 7-08,

You have a nice collection of 7's there... The RUM is really a neat setup... I agree the recoil difference would be negligible between the three...

I just despise the 7mm Rem Mag simply for the fact that many conversations about deer hunting degenerate into, "my 7mm Mag is better than your (insert favorite caliber here)."

 

[Kimber84]

I stand corrected on the use of the word "wildcat". I should have said "offbeat, only available as semicustom, not loaded by any of the major manufacturers" instead. (No, I don't count Nosler and Norma as majors).

So now that that nit has been picked, SAAMI standardization or not ammo availability of 280AI is going to be tough, certainly not compared to 270!

So I repeat:

If ammo availability is your concern, why are you even considering an wildcat offbeat cartridge like the 280AI?

Well....I repeat, because components for 30 cals are non existent. I am finding piles of .270 and .280 brass all over the place along with about every component bullet you can think of.

I've got the 30 cal guns, just looking for something different

 

[dgludwig]

I've got the 30 cal guns, just looking for something different

If you want something a little different but offering virtually the same ballistics and case configuration as the .280 Remington, take a look at the 7X64 Brenneke cartridge. I have a Ruger MKII (RS) Model rifle chambered in this cartridge and it has proven to be very accurate. You won't find factory ammunition for the 7X64 Brenneke on shelves at Wal Mart but I've had no trouble locating factory stuff at places like Cabelas, Gander Mountain and at my lgs for that matter. And, since you reload, there should be no trouble finding something to shoot.
There's no practical reason for choosing the 7X64 Bk (Europe's answer to the .270 in terms of performance and popularity) over the .280 Rm or any other ballistically equivalent cartridge that I can think of except having something a "little different". And there's nothing wrong with that.

 

[reynolds357]

300, I agree that the 7mm Rem Mag. is extremely popular for no apparent reason other than a marketing giant pushed it for many years. The .270 Win is popular because a couple of gun writers made it their life goal to make it the most popular round in North America. In a comparison, I would say the WBY is a slightly better cartridge than the Rem mag. We all know why it never became popular. Wby. designed and built/builds some wonderful stuff. I have almost all the Wby chamberings and love them. Wby. holding them to proprietary status for so many years prevented them from becoming widely popular. Roy made the decision he wanted a niche market and for many years that was indeed where Wby. resided. In my opinion, the .264 Win mag is a much better deer cartridge than the 7 Rem mag. The 7 Rem mag sells like wildfire and the .264 has been relegated to being chambered in a couple $1k+ model Winchester rifles. Marketing, not merits, usually wins the day when it comes to what becomes popular and what becomes a relic.

 

[taylorce1]

I am not cherry picking anything those are the fastest loads listed in any of my manuals. If you want a full case on both let's compare again with fastest loads in 150gr.
150gr 270 Win 61.5gr MagPro 2913fps 101% compressed load
150gr 280 AI 63gr IMR7828 3107fps 103% compressed load
To be completely fair Nosler used a 26" barrel for the 280AI and a 24"' for the 270 so subtract 50-60fps and it only holds an aprox 140fps advantage in 150gr in the same length barrel, nothing earth shattering but certainly noticeable, 140fps is about all that separates my 7mm-08 from a 280 Rem in common bullet weights.

If you only quote one load from one manual you are "cherry picking data". Lets compare that load for the .280 AI you have up there.

150gr 280 AI 63gr IMR7828 3107fps 103% compressed load

This load is straight from the Nosler 7th edition manual.
Hogdon says max load using IMR 7828 SSC (same burn rate as IMR 7828) is 59.0 grains with a velocity of 2902 fps out of a 24" barrel with a pressure of 60,300 PSI. Now if we go back to Nosler's manual what is their most accurate load for IMR 7828? 59.0 grains at 2923 fps and 97% load density.

Now for the .270 data:

150gr 270 Win 61.5gr MagPro 2913fps 101% compressed load

Straight from Nosler #7 again. Now Nosler says its most accurate load with MagPro was 59.5 grains at 98% load density with a speed of 2838 fps. Now here is what Accurate says I can do with MagPro in the .270 Win with a 24" barrel:

Bullet: 150 NOSLER PART
Min: 54.4 @ 2,706 FPS
Max: 60.4 @ 2,955
PSI: 64,680
COAL: 3.320

Are you sure you want to give me that 60 fps for the 2" longer barrel?

So see I can "cherry pick data" as well to skew things in the favor of the .270. Looking at only one book is wrong you need to average things across several different sources of information. I don't agree with running things near 65K PSI all the time either which I think Nosler is doing with the .280 AI to get their published velocities.

There is no real world performance difference between a .270, .280 (running at 60-62K PSI), and the .280 AI. What it boils down to is the only difference you'll ever see between the .270 and .280/.280 AI is.

1. The .270 is offered in a wider array of factory rifles.
2. There will always be more ammunition choices on the shleves for the .270.
3. The .270 will never have the bullet choices the .280/.280 AI has for the reloader.