Anyone think about, try or have information on the .270 Win. Ackley Improved (AI)?

What velocity gain would I get from my current 22" barreled Win. Model 70, especially shooting 130gr. NPs or TSXs?

Saeed on www.accuratereloading.com mentions that it is a great killer of all sorts of plains game.

How about velocities?

I believe the 270 benefits less from the AI treatment than most cartridges. I've only worked with one and I wasn't much impressed.

The 280 is a 270AI and the 280AI is a 270's nightmare.............

The only reason a 280 A I is so good is because the factories underload tthe 280 so much. If it were loaded to the same pressures as a 270 you wouldn't see so much difference in the 280 and 280 A I. I think muledeer has explained this on here before, a lot better than I can.

Bullets matter more than headstamps. At equal pressures,the 270 cain't hang.

The 280AI simply sweetens the pot...............

Check with colmacivor. He's the only one I know of that runs a .270AI, and IIRC, has several.

I have a .270Win. My first centerfire. I have another .270 that Roy really improved. I have always read the .270Win did not benefit that much with the Ackley improvement. It seems that the .250Sav benefited about the most. I once knew a gunsmith that shot 900yd matches with a .30-06AI. Good luck.

I LOVE the 25-06AI..but my .277" disdain is hardly secreted............

Been trying to tell BobinNH that but he won't listen.................................

Can't see making a 270AI myself, now that the 280AI is factory available.

In his book "Handbook for Shooters and Reloaders", Ackley says this about the .270 AI.

In my experience the standard .270 Winchester is a great killer on a wide variety of plains game.

Apparently this is also the experience of a lot of hunters in Africa, especially South Africa, because it is quite popular there.

I have considerable experience with the .270 myself, as well as the .280 Remington and .280 AI. They are all pretty much peas in a pod. You can make arguments for the .280's with paper ballistics, but game all dies about the same when you hit them right with any of the three.

John... You're WRONG... 100 FPS and a .02 better BC is HUGE. Thats the difference between tracking a Big ass Muley 20 feet,,,,,,,,,,,,,,,,,,,,,






or 21!!








Jeesh...




Maybe its time to make your B29 fact instead of fiction High enough BC, fat enough pill...

I'm slow to weigh the impetus of Joe Average's "experience",especially when it comes to bullet or cartridge selections.

Nawwwwwwwwwww...I weigh it far less than that.

Everyone's idea of "far","big" and "good" is different and I'm at ease in extrapolationg ala high standards................

Well, .270 is my favorite cartridge and I see no reason to go to A I. I have nothing against a .280, I think they are two peas in a pod. But there is a reason the .280 benifits form being A I'ed as I stated before. P.O. Ackley stated that of all the cartridges he improved the .250 was best and .257 was second. The two most efficient cartridges he worked with.

Always good to hear your well-balanced opinion, Stick.

I'm more than fair,but alas...not all things is equal.

For much of that which is typically bantied,folks fixate far too much on the superficial,as opposed to simply actually using the goods in question and amassing good practice with same,then applying those skills.

There is however time,places,applications,scenarios,where it is easily discerned even with a cursory gawk,that something is second fiddle compared to something else. There's no shame associated in that or in knowing same.

I could not openmindedly rate the 270 as a 280's equal,due simply to boolit selections available within the two seperate diameters and their inherent attributes associated.

Steering someone otherwise,when talking absolutes,would be a touch dishonest and prolly mean to boot................

RD: Oh, I listen all right,but I'm just not bighting Here's why:It isn't that I don't think a 280AI is a good cartridge,cause it is...it shares all the attributes of its' siblings,the 270 and 280.In standard cases and rifles chambered for 270/280,I want a 22" barrel.If I'm gonna use a larger case than the 06,I want 24" and I want the case to hold a 7mm bullet.The 270 and 280 do just fine in a 22" tube and if I'm gonna use a 30/06 -length action,and a 24" barrel,I'll take the 7 Rem Mag instead,which:

Has more capacity than the 280AI;and

Easily goes faster than a 280AI with any bullet weight,all things being equal;and

Doesn't kick hardly more;and

Can be bought anywhere I travel to hunt!

The 280AI ain't spot news;O'Connor and Huntington wrote about it;Huntington had it and gave it up...A buddy from Boise(who likely has as much 280 experience as anyone on here)had a 280AI back in the 80's,and more than one....I tracked his progress,and agreed with him.Velocity gains not worth it over a standard 280,and the 7RM beat it handily.The 280AI is an idea I had and rejected a longtime ago....cause the 7RM was always right there

Close perusal of load data demonstrates that whatever I can stick in the AI, I can load in a 7RM and do better......AI's are interesting,but I'll watch them from a distance

As to the 270....well,lets just say that several million dead big game animals( on several continents by now)sorta speak for themselves...don't we think? And if I'm gonna get a bigger case,then I want a 7mm bullet,and more capacity...the poor 280AI is just too "in between".....

The 280AI will remain,I'm afraid,the exclusive province of some very astute,knowledgeable rifle guys with very active imaginations......I'm not that bright...I'll just get a bigger case and get more velocity.....Besides, if I want a 150 gr bullet at 3050,I'll run down to WalMart and grab a box of 7RM 150 CoreLokts

A 22" 280AI with 162's,will smoke a 24" 7Remmie with 150's in veddy,veddy ugly fashion.

4 pokes in the belly sweetens the pot........................

I know that ........but I'll stick the 162 in the 7Rem...bingo! We don't need 4 down,do we?

Besides,we can only carry one of these things at a time!

I like the 270 just fine. I am on my third rifle in that cartridge. I just don't think it is worth the trouble to Ackley improve it. The gains are too little.

Instead of the AI treatment you should just get a 24" barrel chambered in good old regular .270 Win.
Ken Waters, Jack O'Connor and I have all found that the 2 extra inches of barrel increases velocity of the .270 Win by over 100fps with the same load and bullet.
Increasing the case capacity through the AI treatment will show very little gain over standard .270 when shot through a 22" barrel.
I was amazed at the velocities I got from the same loads when I got my LH 700KS with it's 24" barrel.
Quite frankly I don't understand why any mfg would handicap the great .270 Win with a 22" barrel. I'll never own another .270 without a 24" or longer barrel.

The so called "AI" cartriges are a waste of time. The benefits are minimal.

You will reduce the value of your rifle and gain almost nothing.

On the other hand guns are fun to fool with and don't cost all that much.

Qouting Ken Waters on the .270 Win.
"...reducing barrel length below 24 inches is like installing a governor on a sports car to restrict its speed."

Here's what really got me thinking about the .270 AI that has the possibilities up higher than the 280 or 280AI? I don't know...











Lots of praise- and why I ask- would you give a 270AI as an option for a mountain hunting rifle for sheep, goats, mule deer, black bear and some coyotes and wolf?

You'll not catch me making mention of 150's in anything .284",but you were lauding 150 Factory loads in your 7Remmie,like they were sumptin'. They ain't.

Is 2-4" of barrel length decrease and adding another round in the belly,a fair trade,when musing a 280AI over a 7Remmie? I'm of the opinion that such things start hedging real world bets rather nicely,as per a utilitarian rifle that is actually shot in the field,as opposed to one speculated upon.

Gimme the Montucky 7WSM...mainly because I shoot 'em all..............

2" of barrel won't cost a 25-06 100fps.

Rest assured that ain't a guess................

With the new powder, the 270 AI seems faster than a regular 270WSM and almost a Weatherby- It looks like with biger bullets that it might surpass the 280 and 280AI in capabilities too?

But according to experts I trust such as Mr. Waters and Mr. O'Connor, as well as my own experience, 2" of barrel length lost WILL cost the .270 Win over 100 fps.
2" extra barrel length is no handicap that I can see.

And if you load 17 into the WSM and WBY you will get higher speeds.

Pressure for pressure with the same barrel length, no Ackley
round is going to get within 200 fps of a magnum round.

Outside of saving yourself time trimming brass the Ackley is
most overrated. You can load it's unimproved daddy to within
50 to 75 fps of it.

You are as full of [bleep] as they are,if you even begin to muse such a copious load of BS........................

A 26" 257Wby doesn't have 200fps on a 24" 25-06AI....let alone one in 26" That ain't a guess.

A 24" 7mmRemmie doesn't have 200fps on a 280AI...that ain't a guess.

'Course,I shoot em all................

I liked the bumper sticker I saw in Montana that said
"You ain't S*** unless you have a 280" only thing wrong it should have been a 280 AI.

270 is hallowed and sacred don't mess with it. Besides a 270wsm will beat the 270 AI with no great pains. If you really want to trump them all get the 270 Roy and be done with it.

WSM and 2.5" Roy capacities rate another peek................(hint)

My Tikka T3 with 24" barrel chambered in .270 WSM is no faster weight for weight than my 24" .270 Win.
Not only that but the WSM's (I've owned the 7 WSM and the .270 WSM) were a pain to load.
I haven't even mentioned the fact that the WSM's have the less than optimal rebated rim on them too.
.270 Roy I'll give you. Very nice round.
To the original poster I'll say again that the plain old .270 Win WITH A 24" BARREL will give you more of everything than a 22" .270AI.
You have to pull the barrel to do an AI as well so I'd recommend either buying a 24" barrel for your present rifle or find a 24" rifle already chambered to .270 Win. They are plentiful for you right handers, not so much for us lefties.

I'd be interested for a quoted reference from Jack O' re: the 24-inch .270, for, IIRC, he shot and recommended the 22-inch version, claiming 3140 fps in his handloads using 4831.

Why don't we just say that the difference between a 270. 280 Ackley and a 7RM is basically the same, up or down. I'm a reloader so you might as well add the costs to reload each if discussing all the merits. 280 brass is cheaper than 7 mag and in a pinch you could use 06 brass as well for the standard or Ackley version of the 280. Less powder, recoil, muzzle blast and usually packaged in a light config make the 280 Ackley more attractive to me than the 7RM. Unless your ammo doesn't make it to your destination for some reason (and everything it was packaged with) ammo availability is a non-starter for me. For me, it's the sum of little gains that make the whole package more attractive than either the 270 or the 7RM. Won't argue the paper ballistics cause that's all that it is, paper and arguing.

On page 1030 of Ken Waters' pet loads 8th edition Ken writes;
"In a letter years ago, Jack O'Connor told of two of his .270 Winchester rifles, one having a 22 inch barrel that chronographed 95 fps less than his 24 inch barreled rifle with 130 grain bullets and the exact same load. It's interesting to note how closely that difference agrees with my findings."

As for Mr. O'Connors preference I have no information.

A few yeas ago somebody, I think it might have been Boddington, did a comparison of the .270 Win. and .270 WSM. He used the same rifles with the same length barrels. He said that with some loads the WSM was faster and with others the .270 Win was faster. At the end of the article he said if he owned one or the other he wouldn't sell it to get the other, not enough difference.

PWC: You're right....they ain't.But they go bang in a pinch.....if I need them,away from home,was my point.

I'm with you on the extra round;situations do pop up.....


I shoot them all,too...range,and when I hunt....I through speculating.....

I'm so disappointed.... I thought you guys were talking about the 30'06.......
Sorry Dober. I stole your line. E

Tomorrow I'll start a thread on " 30/06 twist......1-10 or 1-11....beer cans or bust...

'gam,

The "troubles" you cite are squarely commensurate with your "experience" and that'd be an aged trend.

It takes some doing,to pull enough spark plugs on the WSM,to slow it to '06 case capacity velocities. Nawwwwww....it takes more than that.

I doubt you could reliably get the pointed end of a bullet,facing out of the casemouth..................

This is a good thread. I always thought that the 270 had enough neck that it could be moved up............sort of like a 300 wm or 300 sav..........and that would allow enough additional powder to make it worthwhile!


Guess I was wrong!

The 270Gibbs is your huckleberry...............

Since PWC is the smartest, most experienced person to ever visit the Campfire you need to listen to him. It seems that his experiences are more relevant and valuable than anyone elses.
He must even have ESP too because he knows that I am incompetent and inexperienced even though he doesn't know me from Adams off ox.
I'll trust Mr. Waters and Mr O'Connor. You can have PWC!

I ain't guessing,therein lies the difference(s).

You can bullshitt the fans,but you can't bullshitt the players...............

Like I said PWC has the only relevant experience and since he's a PLAYER then he must be heeded.
With 781 posts in 13 days it looks like he's been playing with the computer more than anything lately!
And that ain't a guess!

Hardly suprised that my post count intimidates you and drastically ruffles your feathers of insecurity. That anxiety is wellfounded,as is the uncanny connect percentages that I bat...if only because I'm not forced to guess.

I'm much looking forward to you getting your first clue,despite the great odds against same................

OK

Sit tight,shut your yap,take notes and you'll learn sumptin'...................

brooks,
It's not worth AI'ing the 270.

If it was my 270, it would stay just that. I have/had 270's with 20, 22, 23, 24, &26 inch barrels.

I prefer 22-24" barrels. They seem to be the best compromise in handling characteristics for hunting. The longer barreled rifles were for more target type shooting and playing around at the range, just to see what they could do.

PWC,
"Stick around and learn something"..... probably not from you, but please surprise me.


Shot placement relegates all other discussions to secondary importance.

Stop the .270 improved madness...if you need more from a .277" tube, rechamber for the .270 Wby.

CRS,

Should you take issue with anything I've mentioned,denote same and I'll open your eyes..................

PWC please explain how your experiences are more valuable and relevant than Mr. Waters', Mr. O'Connor's or anyone elses experiences.
On second thought, in your megalomaniacal madness you probably think you ARE more important and experienced than Mr. Waters etal.
You just stay here and keep all of us apprised of your uber valuable experiences. Me, I'll be out in the woods putting my experience to work far from any computer.
Have a great day and I look forward to gleening the benefits I can derive from your voluminous postings.

Just be cool nsaquam, I think that in the 14 days of PWC, that NOBODY CARES. Have a good day.

Buying 270AI dies could be a deal killer. $110 extra from RCBS.

A .277" groove barrel and a 270AI reamer are priced on par.

257RI and 280RAI dies are ok.

One could make a seater die with the chamber reamer, and size with a Lee Collet 270 Win die. Pitch the brass when it needs a shoulder bump. That would be cheap enough.

How do people find this stuff do bring it back after 6 weeks? I rarely bother to click on page 2...

Not so sure about that. Mind you, lots of people think that the 25-06AI has something to gain over the 25-06 so, with the 270 Win. having a larger bore diameter, it should show even more improvement.

I'd stick to the 270 Winchester.

As I understand it, the only way to improve on a .270 in a meaningful way on a 30-06 case is to go with the Gibbs. If I remember correctly it was one of Rocky's favorites, and the one he said benefited most from the "treatment". Trouble is, it's a giant PITA to form brass. Start with 30-06, form a false shoulder, neck to .270, blow it out, FL size...PITA

You'd be almost as well served by just necking down a 7x66 Vom Hofe, at which point you might as well have bought a .270 Weatherby. And if you're gonna do that, you've already missed the point about everything that's great about a .270.

I've always liked the idea but in practical terms, the 270 Winchester does it very well all by itself.

I have owned 2 270's, both with 22 inch tubes. Still have one of them. I may have had slow barrels but both of them were pretty much all done at a little under 3000 fps with 130's and 2800 fps with 150's. From reading other postings I am sure that my results were not typical, but that was my experience. Twice.

I like the 277 bore and had lots of Nosler Partitions, 150's and 160's, that I obtained for $10 a box at a sale, so I had a 270 Roy put together. With a 24 inch barrel I have no trouble adding 250-300 fps to anything I was able to squeak out of the 270 Win, and at lower pressures to boot.

Really like the 284 bore also, but where the rubber meets the road there is really very little difference other than what's in your mind. I seriously doubt that a 7 RM or 7 Roy will do anything on game out to 500 yards, which is my self imposed limit, that I cannot do with the 270 Roy.

Opinions vary, mine is that either the 270 or 280 AI versions largest advantage lies in the mind of the owner.

GH your velocity deficit was due to the 22" barrels.
In my experience a 24" barrel is required to get full velocity from the .270WCF.

chamber yourself a .277 in roy fashion in the action you like; hang 26" of bbl on it and run 130's (think accubond,interbond,etc BC .435 plus) at 3500. Its not a feat to do so safely. 7828 is your huckleberry. No 270win AI, 280 rem AI and maybe not a 7RM gonna touch that. Dont forget your freebore. You might be surprised how well it'll shoot.

There is a lot of truth in the above post;but maybe some misconceptions, too.There are too many 22" barreled 270's out there that routinely break 3100 fps with a 130,and it has been done by too many people in too many rifles over too many years(very safely)to seriously question whether the cartridge can safely achieve those velocities,especially with todays powders.Yes a 24" barrel may (or may not) give more velocity than a 22" but this assumes both barrels are "equal",and they almost never are.

I have owned more than one 22" 270 barrels that would safely give 3200 with a 130.

I do agree though that going AI is pretty much a waste of time over the standard cases when there are perfectly good belted cartridges with significantly greater capacity.

With bullets up to 150 gr in weight(where 270 cal generally tops out) I could never see the advantage to a magnum capacity 270 over a 7mm...there are so many good full spitzer 7mm bullets out there of 160-175 gr weight,that I feel a mag capacity 270 has little to offer,and this is where the 7mm magnums really trump.There is nothing a 270 Weatherby does with 130 gr bullets that cannot be accomplished with a 7 mag and the same weight bullet.There are no full spitzer bullets weighing more than 150 gr commonly available in 270 that I know of...

BTDT with all these things except the AI's which,to me, are trends that have been hanging around for years,and pretty pointless.I let friends do the experiments with the 280AI and report back....won't waste my time.

On a standard case, give me a 270 or 280 with a 22" barrel and a nice light rifle....if you wanna beat those two, and intend to use a 24" tube,get a magnum capacity 7mm.The rest is fluff.

Stick must have one unsatisfying home life to spend so much time in front of a keyboard.

Like I said...

It's amazing that not one person has AI'd the 270 but PWC.

I'd sure like to see some loading data posted on actual results, enough bickering...

In the late 70's a friend put a 29" Hart barrel on a Rem 7oo chambered in std 270 Win. It was unreal fast and accurate...can't remember any hard stats. Memory is fuzzy, but I think that he was shooting the 90g Sierra's at 3900 or close to it ...don't take that number to the bank. This long barrel'd 270 put wings on full grown chucks.

He kept talking about making an AI out of his to eliminate case trimming.

Interesting, I was at the range yesterday and someone had a 270 Win AI!

The 270 AI version with his handloads of 150 gr. Partitions produced between 2974 FPS and 3017 FPS over the Chrony. 24" barrel Model 70. Accuracy looked to be about 1" at the 100 yard backstop.

Same here. For me it's 24". Was just re-reading as my buddy is going to settle on the plan non-AI 270 Win. and use the slightly longer barrel.

Hey Bluedreaux! It's baaacckk!

Great old thread with a bunch of guys I admire.

It begs a question though; has our rifle geekery changed from velocity to gear?

Since this thread started I explored a few ideas in velocity, but always come back to running custom turrets on my most accurate .270 and favorite load.

It sure has been satisfying to kill farther and more repeatedly than I ever thought possible with a .270 It just sort of happened over the years while I was studying lower pressure and higher BC, but using the one rifle I rely on.

.277 bullet fired from a 22" barrel will not kill deer. but a 6.5 Creedmore kills like lighting a a mile away. or so it is said

fixed it for you ;-)

Seriously though: 22" .270 AI

-> Why ?

= Hate Tedious Case Trimming Task
= 280 AI Envy

do you not agree that the difference between the 270 Win and the 270 AI would be about 2" of barrel?

I'd rather have a 24" 270 Win. than a 22" 270 AI.

Either will handle 100% of N.A. big game and about 90% of the rest of world. The other 10% can be done with a 300 Win mag and a 416 Rem Mag.

Eight years and running. I wonder how it came out?

I would go 6.5 saum now instead.

Nobody makes a 26" 270 WSM -->> Hmmmm

I would go 6.5 SAUM too

I know this is an old thread and, although it is a good read, I can see no real reason for a .270 Win AI. Looked into building a .270 Gibbs a few years ago and the numbers just didn't work. The gains in velocity just didn't justify the need to form brass for full power loads or the lack of factory ammo in a pinch(sometimes [bleep] just happens right?). I could see the 280 AI being a better solution for this reason alone, if you must. I'll just stick with the 270 WCF and be happy.

With RL26 and a 24" barrel, and 150 gr bullets, you might get 3100+ fps out of a 270 AI.

Anyone with experience here?

.270 GayER

Well boys I owned a 270 AI, my first wildcat! It was a 700 BDL I had rebarreled with a 24 inch Shilen tube. Shot fine and I got on average almost a hundred feet per second more that I got from my first 270. Traded it off for a nice light 30-06. That is the best way to improve on the 270!

Guy at the range on Sunday was shooting near 3100fps with RL26 and 140gr. Partitions; should be possible.

Dang, 2009 called.....it wants its thread back.

Apparently, you can get those velocities nowadays with RL26, so no need for the AI; else, likely get even more with the AI if that's what you really want.

Y'all keep resurrecting these old threads... Giving me ideas...

OK. This is from memory but I did rechamber a 24" Winchester from 270 to 270AI, to 270 Gibbs, and then, with enough setback to cleanup the shoulder, to 270 Weatherby. The owner of this rifle used the casehead expansion method of determining excessive pressure (I don't want to hear it) and loaded each to where he saw measurable expansion then backed off to where he saw none. He used Winchester brass for the standard cases and Weatherby brass for the Weatherby. As I recall, the resultant velocities, with 150 Hornady's and 4831, were:
270 Win 2940
270 AI 2990
270 Gibbs 3070
270 Weatherby 3180
He felt the Weatherby could have done better but the brass was soft. Could be.
Right now, I'm having an issue which frequently rears it's ugly head on this site where the typing function keeps failing so I'll say (just happened again) no more. The beneficaries of this are those who hang out here because they don't have to read as much of my stuff. GD

Greetings... Just back from my annual Wyoming antelope hunt with my son and grandson. My 6.5-06 AI worked just fine with a Hornady 143 ELD-X. I usually build a different rifle every year. Gun nut....reloading geek (whatever). Does anyone know a smith with a 270AI reamer? I have a 24" Rem 700 Custom Shop 270 Win that I would like rechambered to 270 AI. Not intending to re-ignite any campfire flames, just looking for info. THANKS

Lol….

Well heck with all the new bullets why not a fast twist 270AI? Could sort of reinvent the wheel and not quite match the 280AI. But it would be fun.

Alpineprick....just couldn't MYOB could you....

Thanks rickt300. I have (2) 280 Remington Improveds and an original 280 Ackley. Lots of better powder and bullet options out there to experiment with.....Enjoy the journey!

Everything everyone wrote years ago on this thread about the AI not really offering much at all to the 270 Win is exactly right.
BUT, that said, as a looney, I would have a ball with a 24" barrel, 8" twist, 270 AI. Would have almost as big a ball with a 24", 8" twist, 270 Win, but that would be much less of a pain in the butt so what's fun about that?? ;o)
In 2022 I wonder why all .270s aren't twisted 8" anyway. Don't see it hurting the 150 grain and less bullets but opens up a lot with the new high BC heavies.
Rex

I use Hornady 140gr SPBT Interlocks now (see John Wooters article Hunting July 1986, where he says the 140 gr bullet has been one of the best improvements to the 270). For a hunt for Tahr and Chamois to New Zealand a few years ago my load was chronographed at 3,044 fps out of my Winchester pre64 featherweight’s 22” barrel. That’ll do me. According to Wooters this bullet (with a reasonable BC) shoots flatter than the 130 gr and has more energy beyond 100 yards than the 150 gr. Wooters says “that’s some compromise.”

Happy to email or message the article to anyone who is interested.