280 AI or .270

[Unlicensed Dremel]

First off, I think you've asked the right *question*. In the past, the answer would have been .280 AI.

But nowadays, Hornady and others have really upped their game in terms of the BC (and consistency) of .277 Bullets, so probably .270 has the edge, all other things being equal. For myself, since I already have other 7mm rifles, and thus a stock of bullets to reload with, it's not 'all other things equal'.... the new high-BC bullets are the game-changer. .270 win was always an excellent long range, all-purpose cartridge. Now it's all that PLUS *very* long range, if you have a rifle that can do it (and skill).

[Ridgerunner665]

The 7mm bullets still have equal to or better BC's than the 270 bullets...Hornady .277 150 SST's are .525, same as the 7mm 150 Interbond and SST...and the 280 Ackley can launch them at higher velocity.

Bryan Litz tested the Nosler Accubond LR bullets...the 150 grain 270 bullet fell short of its advertised BC by 12%....coming in at .543 in a 10 twist, and .569 in a 7 twist...both below the 7mm 150 Accubond LR in a standard 9 twist (.576)

Again, I'm not trying to bad mouth the 270, not at all...

I'm trying to say that the 270 has gotten better through better bullets...and if you Ackley the 270, it is equal to the 280 Ackley in almost every way...but no better.

Both rounds, in Ackley version....just puts them right back where they started...pretty much equal, when loaded to the same pressure with the same bullet weight.

The 280 will always have a slight advantage with heavier bullets, due to the expansion ratio of the powder/gases going through the larger bore.

For about 20 years...I've always thought the 280 Ackley was a very well balanced round...it does about all that can be done in a non-magnum round...many others are maybe just as good, but none any better when all factors are considered...brass life, barrel life, ballistics, magazine capacity, recoil, and cost of ownership.

I don't see why it took so long for it to catch on...except for the fact that Remington made so many bad decisions with the original 280....and that is my sole reason for posting all this....I don't want and will not participate in any arguments about "which is better"...but I will say, as many times as it takes, that the 280 Ackley is worthy, capable, and deserving of success.

I'd just like to see it take its place among the many great rounds out there...and I'm sure it will in time, now that it has finally been standardized....after all, it didn't hang around for 50 years as a popular wildcat just because of its good looks.

[Unlicensed Dremel]

Good points; I'd have to agree - that's my choice of the two (.280 AI).

[Ridgerunner665]

And the Ackley doesn't necessarily "need" to be pushed hard...though most will, including me.

During the initial break in though, my plan is to shoot 140 grain Accubonds using H4350 powder. I should be able to get them above 3,000 fps easily, and accurately, and that load will kill any whitetail that ever walked the hills of east Tennessee out to about 700 yards, if I wanted it to.

The H4350 will go easier on the barrel because the charge will be smaller...the pressure will still be up around 63,000 psi...but the smaller charge will wear the throat less....and I have several pounds of H4350, my last rifle was a 30-06.

I probably don't even need to worry about barrel wear, I don't shoot much these days...too much work, not enough play...but I've reached a point where I seem to want to account for everything and find the optimal balance...must come from working for a living, lol.

I have worn out a few barrels over the years...a couple of 308's, a 300 Win Mag, and a 25-06...there was a time when I had a lot more time to "play"....then I got married, and had kids, and bought a house, and a truck, several hundred pairs of shoes, etc...well, you know how it goes, lol.

[reynolds357]

The .280 A.I. should be relagated to obsolescence with the arrival of the 7 WSM. When compared to the 7 WSM, I can honestly not think of any reason one would want the .280 AI. A regular .280, I can see. Ammo availibility and price for it are reasonable. For the A.I., you either have to pay out the rear for ammo or you have to fire form brass. One can shoot a regular .280 in the A.I, but that is about pointless as well. The WSM is a short action beating a long action in performance. The 7WSM is one of the most accurate cartridges I have ever seen. It wins a good share of 1k matches.
I understand that we all "like what we like." Having said that, I am building a 7x57 Mauser just because I want one. Cartridge to me is worthless since I have two 7mm-08's, three 7 WSM's, Three 7 Rem mags, and a 7 Rum. My above opinion is based simply on performance and it discounts nostalgia or "wants."

[taylorce1]

All this pontificating is pretty much pointless. Yes, the .280 AI will be faster than the .270 just because it has a slightly larger powder capacity. Yes, the .280 AI will have the better bullets simply because it is a 7mm. Yes, on paper the .280 AI is the better round because of all the above.

However, in real life the .280 AI and the .270 are essentially twins. Powder capacities are nearly identical, so the same powders that make the .280 shine will do so in the .270. Truth is the .280 AI will only beat the .270 Win by 100 fps or less in most cases with the same weight bullet. So even with the BC deficit the .270 has you'll not see any real difference until you're well beyond the normal hunting ranges most game is shot. Let's face it neither is a target round because there are way better choices.

It really boils down to what the hunter wants. For me I've been there done that, and I'll stick to the .270 Win. It does everything I need within reason and is available by every rifle manufacturer out there. The same simply can't be said for the .280 AI, but it doesn't change the fact that they are both good cartridges in their own rights.

[Ridgerunner665]

I thought we were comparing it to the 270...but OK...it'll stand against the 7mm WSM too.

The areas where the Ackley beats the WSM...barrel life (for several reasons), magazine capacity, and recoil.

In all other areas...they are equal...brass and ammo for the WSM isn't exactly common, or inexpensive.

Ballistics are identical up to 160 grain bullets (within 50 fps)...common hunting weight bullets...the WSM does have an edge with heavier bullets, due to its greater powder capacity.

Remember...the 280 Ackley is everything the 7mm SAUM was...but with more rounds in the magazine, that matters to some people.

It may not be for everybody...but to say its useless is a bit much.


Edit: I only shoot targets to sight in scopes...I got my Ackley to hunt, and hunt hard, all over the US...not trying to win matches, just fill freezers...it shoots flat, hits hard, excellent in the wind, easy on the shoulder, in a durable rifle...what's not to love?

[reynolds357]

Two of my 7 WSM's holds 4 in the box and one in the Chamber. A 7 WSM can be loaded to be a 280AI, but a .280 AI can not be loaded to be a 7 WSM. Barrel life of the 7 WSM and the 280 AI can be identical.

[Ridgerunner665]

Originally Posted by reynolds357

Two of my 7 WSM's holds 4 in the box and one in the Chamber. A 7 WSM can be loaded to be a 280AI, but a .280 AI can not be loaded to be a 7 WSM. Barrel life of the 7 WSM and the 280 AI can be identical.

The barrel life equation isn't that simple here...short neck vs long.

I can live with 50 less fps...any given barrel will vary that much, some much more...so I think most would never notice a difference, if there was a difference.

4 in the box on a WSM...do tell...what are they?

[Ridgerunner665]

I spent a good chunk of money on this rifle...and didn't do it on a whim (I'm just a blue collar guy, truck driver)...I looked at every 7mm caliber available, from every aspect, from every maker (including custom shops)...could have had anything I wanted, up to and including a 7mm Allen Magnum (still kinda want that one, lol)...but when all factors were considered (objectively)...the Ackley won.

I didn't set out wanting an Ackley...I set out wanting a good medium range hunting rifle...the decision to go with the Ackley came after much research and many nights dreaming about ballistics charts, lol.

It came down to the Ackley and the Rem Mag in the end...but the Ackley just plain made more sense for all the reasons already mentioned.

Would I run out and trade my 7mm WSM or Rem Mag if I had one? Nope...I wouldn't.

But I didn't have one...

My buddy shoots the 7mm WSM (model 70)...it's a fine round...shoots flat, hits hard...it just didn't quite fit my "mission parameters" as TiborasaurusRex would say, lol.

I used his process of elimination to select the round....had nothing to do with what I "wanted".

[reynolds357]

Winchester Coyotee with modified box, stock, and follower. You can almost kram 4 in the box stock. You dont have to make much room.

[Ridgerunner665]

Originally Posted by reynolds357

Winchester Coyotee with modified box, stock, and follower. You can almost kram 4 in the box stock. You dont have to make much room.

Cool...worthwhile modification in my opinion.

[Bart B.]

The truth and facts regarding both cartridges' ballistic performance with bullets of equal weight, sectional density or ballistic coefficient will only be observed when both have equal peak pressures, SAAMI spec test barrel specs for the caliber, bullet diameters equalling groove diameters and barrel lengths. Not estimated; measured with identical systems hard mounted so muzzle velocities are not influenced by rifle holding pressures.

Otherwise, one or the other may be loaded too hot and have an unfair advantage. Leveling the playing field makes comparisons realistic.

[Unlicensed Dremel]

When compared to the 7 WSM, I can honestly not think of any reason one would want the .280 AI

Only one might be magazine capacity - holding 4 instead of 3. But that's not much of a reason.

Oh, but also shooting really long bullets - if your WSM is in a short action, it's easier to seat long bullets long (without greatly compromising powder capacity), with an AI than with a WSM - *depending* on the leade.... but this can be fixed by either using custom barrel with longer lead, or a long action for the WSM, or both. So it's not much of a reason either. The WSM also holds 2 or 3 more grains of powder (in h2o).

The .280 AI may be in the unusual position of being simultaneously "the least over-hyped of any AI round", yet still generally somewhat-over-hyped.

As far as buying brass though, for .280 AI, it's not as bad as it first appears, due to the Nosler Trophy Grade Ammo being around - since the Nosler brass is very good, the price of the Nosler T.G. ammo is really NOT that high at all, considering you get very very good factory ammo (essentially super-premium), AND end up with very good once-fired brass. That ain't too shabby, for what, $52 a box? Still higher than starting from scratch, but it's a pretty good value, seems to me, *if* you like to shoot /hunt with the factory ammo sometimes. If you reload all ammo, period, then no it's not a good value at all.

http://www.midwayusa.com/product/442...ProductFinding

I just sold my .280 AI rifle, and kept my 7mm RSAUM. To me, it was a dead heat, but to be honest, right or wrong, one of the two kickers which were the deciding factors for me in my mind, was the reduced feeding reliability or "slickness" of the steeper AI shoulder. The other factor is irrelevant to this discussion; rifle-related, not chambering-related.

[Ridgerunner665]

Originally Posted by Bart B.

The truth and facts regarding both cartridges' ballistic performance with bullets of equal weight, sectional density or ballistic coefficient will only be observed when both have equal peak pressures, SAAMI spec test barrel specs for the caliber, bullet diameters equalling groove diameters and barrel lengths. Not estimated; measured with identical systems hard mounted so muzzle velocities are not influenced by rifle holding pressures.

Otherwise, one or the other may be loaded too hot and have an unfair advantage. Leveling the playing field makes comparisons realistic.

Yep....they're that close.

My intention is not to "hype" the 280 Ackley....enough people do that already, lol....I just want to speak the facts.

Mostly just want to make it clear that it is a darn fine 7mm round that deserves some respect.

Like a gun writer said in an article....its "mild mannered but wicked"....sums it up pretty nicely.

[old roper]

You don't have same SAAMI spec Pressure for the 280AI or 7WSM and appr 10gr less case capacity for the 280AI so your never going to have them equal.

Biggest percentage of 280AI are custom and Nosler only has two loads for the 280AI and 16/20 for 7WSM from Federal,Win and others.

Ridgerunner665, I've had running battle with Taylor over 280AI but I do respect his opinion and we all have choices. I'm not much into comparing but I do agree with Taylor about the 270 and 280AI and running ballistic on my 270 using Nosler 150gr ABLR is pretty close to your data for 280AI with 150gr ABLR.

Since you haven't chronograph or have that rifle yet but for 800yds you post 1955.7FPS and my 270 with Nolser 150gr ABLR is 1914fps so that's a difference of 41.7fps and that's from Lilja 1/10 twist barrel 24 1/2" long.

I read Litz article on LRH here copy of that

http://www.longrangehunting.com/foru...esults-137554/.

[Bart B.]

Old roper,

SAAMI's website says the 280AI and 7WSM have the same pressure specs as listed on these pages:

http://www.saami.org/specifications_...essure_CfR.pdf

With approximately 10gr less case capacity for the 280AI, you'll have them equal because their powder charge expansion ratio for the case size is about the same. Same thing with 7.62 NATO ammo and .30-06 cartridges; the 7.62 has about 20% less case capacity but has the same peak pressure; 50,000 CUP.

For comparison, check out the .270 Winchester's equal pressure specs then the .280 Remington's lower ones.

Cartridge and chamber specs for all three plus the .280 Rem. can be seen at:

http://www.saami.org/PubResources/CC...0-%20Rifle.pdf

One can load all these cartridges to the same pressure specs very easy to compare their ballistics. Adjust the powder charge.

[reynolds357]

U.D. I am not exactly sure how long Winchester cut the throat in the Coyotee. They put a huge amount of "free bore" in it. The limiting factor of how deep I can seat a 150 ballistic tip is getting enough bullet in the neck to hold it, not hitting the rifling.

[Ridgerunner665]

What Bart is suggesting is very easily done with QuickLoad...I know he said "not estimated"...but that's about the only way I can make sure all other variables are the same.


Gonna run it after I eat....I think I know what the results will be.

[reynolds357]

Bart, I am not sure what exactly you just said. Part of it went over my head. What I do know is the 7 WSM will handily whip the .280 AI on the Chronny. The heavier the bullet, the worse the whipping becomes. As the barrel lengths shorten, the advantage shifts even more to the WSM.

[Ridgerunner665]

Cartridge : 7 mm WSM
Bullet : .284, 150, Nosler Accubond LR 58734 G7
Useable Case Capaci: 72.053 grain H2O = 4.678 cm³
Cartridge O.A.L. L6: 2.860 inch = 72.64 mm
Barrel Length : 24.0 inch = 609.6 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 64000 psi, or 441 MPa
or a maximum loading ratio or filling of 107 %
These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

104 loads produced a Loading Ratio below user-defined minimum of 90%. These powders have been skipped.
Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
Norma MRP 99.9 69.2 4.49 3201 100.0 64000 13318 1.147 ! Near Maximum !



Cartridge : .280 Ack Imp
Bullet : .284, 150, Nosler Accubond LR 58734 G7
Useable Case Capaci: 65.678 grain H2O = 4.264 cm³
Cartridge O.A.L. L6: 3.340 inch = 84.84 mm
Barrel Length : 24.0 inch = 609.6 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 64000 psi, or 441 MPa
or a maximum loading ratio or filling of 107 %
These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

94 loads produced a Loading Ratio below user-defined minimum of 90%. These powders have been skipped.
Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
Norma MRP 103.4 65.3 4.23 3151 99.9 64000 12974 1.121 ! Near Maximum !

[Ridgerunner665]

50 fps....


5 grains of powder can only do so much...and its often not as much as we'd like.

[Ridgerunner665]

Old Roper...is your 270 a WSM?

Or were your ballistics figured at 4,000 feet?

For the record...mine were at sea level in standard atmosphere.

[Ridgerunner665]

...loaded to 63,000 psi, perfectly safe in a modern bolt action.



Cartridge : .280 Rem.
Bullet : .284, 150, Nosler Accubond LR 58734 G7
Useable Case Capaci: 59.175 grain H2O = 3.842 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length : 24.0 inch = 609.6 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 63000 psi, or 434 MPa
or a maximum loading ratio or filling of 107 %
These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

84 loads produced a Loading Ratio below user-defined minimum of 90%. These powders have been skipped.
Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
Norma MRP 107.0 60.9 3.95 3093 99.6 62931 12160 1.115 ! Near Maximum !

[Bart B.]

Reynolds, SAAMI's specs on muzzle velocity show:

140-gr. at 3,225 fps for the 7mm WSM

140-gr. at 3,260 fps for the .280 AI.

And both at the same pressure specs; max average of 65,000 psi.

As far as I know, both are from 24 inch barrels. If another barrel length is used for some cartridges in the page I linked to, they're noted at the bottom of the page.

I don't know what "went over" your head, but SAAMI's stuff says the AI whips the WSM with equal peak pressure and 24" barrels.

Ridgerunner, SAAMI specs for the 7mm WSM and .280 AI groove diameter is .2837" and bullet at .2845. Does Quickload let those exact dimensions be entered for calculating data?