Home Forums Hunting & Shooting Hunting Rifles learn me about the 280 AI

Bob is a great guy and his vehemence on this subject, as well as his ad hominem attacks, surprises me.
He certainly IS better than that.

I absolutely agree, both Bob and Dogshooter are usually 110% stand up members hence why I'm so surprised with the replies.

Ya can't tell me you ain't seen this before.

Everytime someone says "My 280AI can run close to a 7mm mag" Bob starts gettin' cranky and the next thing ya know everybody is an dumbazz and ya shoulda just built a 270.

Then Nsqamn starts in with the fugged up Saami specs for the 7mm mag and the book loads for the 280AI. Now Bobs all slobberin' and spit starts flyin!!!

"62k this...65k that.... take yer two extra inches of barrel and shove it up yer puddin ring ya dummy!!!!"


This [bleep] is hilarious! And it is also what makes us rifle loonies.

So fugg all y'all. I'm gonna run my 7mm Rem Express Improved!

To those who care I saw a 280 AI Ascent in a gun shop about 30 mins ago. 1700 bones is a ton load far as I'm concerned.

Dober

Buddy of mine is planning a 7mm Gibbs build with a 29 inch tube, ought to run with a 7 Mag and outrun a 280ai with the right loads

This is just me but tween the Gibbs and the AI there's no way I'd do the Gibbs (again).

Run a 29" on all 3 and lets see the sparks fly...grin

Dober

How did that Ascent handle, Dober?

I like the fit and feel of my Montana Ls in 30-06 and 280AI.

I like the 280AI more than my7mm RM and 280 Rem, but not as much as my 7-08.

That should light more fire in the rifle looney world....

taz-I didn't handle it today but in October I handled one at the range. 4 me they're just too light to be an effective tool for me. Plus, I want absolutely nothing to do with a brake.

I have a Lil Sky .308 and totally love the rig (though I wish it had a bit more barrel weight). All the other Montana's leave a bit to be desired for my likes.

Dober

Well he got the idea that he needed a Gibbs when he was shooting with me when I was working up loads for an 8mm Gibbs, He was trying to decide which one when he came across the 7mm dies and barrel on the cheap, old military barrel bore looks just about perfect...

Rainy my friend... I'm not questioning anything. Your within what you and a few guys think are safe... that's cool. You know what you're doing... I'm not questioning it....

I'm just saying I've had a few... the 7 is quicker... period. And, 65k to 65k the 7RM dominates the AI.... some aren't comfortable with that, for those guys there's the AI.

I can respect that Dogshooter and as I have said before yes apples to apples concerning barrel length the 7RM will outrun a .280 AI

I down loaded this from another site.This guy strikes me as careful and well reasoned handloader and 280AI user.Unfortunately when I downloaded the article not all the data came up, but IIRC from 3 minutes ago, he topped out at 3250 with a 140 gr bullet and a flat 3000 with a 160.

Note his comments about the 280AI being a "soft, unpretentious" 7 mag. Note also,his comment on water capacity of the case at 67.6 gr of water to neck/shoulder junction.I didn't do it, but compare that to a standard 280, a 7 Rem Mag,a 7mm Dakota,STW,and Mashburn.Lemme know if you care to.




Revised 03/21/02







The improved 280 Remington Case.







280AI with 168gr Berger VLD bullet

The 280 Remington Improved comes in several versions. The 280 Ackley Improved with the 40-degree shoulder is perhaps the most the common. The RCBS version by Fred Huntington with a 30-degree shoulder is more suitable for hunting with magazine rifles, for fast reloading. Although deliberate and slow reloading is recommended for either shoulder, when the magazine is used. The 30-degree shoulder creates fewer jams.

There are some very short-neck versions, like the 280 Gibbs. These versions will increase the powder capacity even more for a little extra performance, and will extract every ounce of power from the 280 Remington case. The only problem I have with these short-neck versions is that they are completely custom in all respects, including reamers, dies, and fire forming methods. But they are real performers.

Holding long 7-mm bullets concentric in a hunting type rifle with a reasonable neck wall thickness of 0.012 to 0.013" is not easy with only 0.280 or less neck length.

One version has a 0.300 neck length, which allows a 0.030" longer powder room than the standard fire formed version. For single shot rifles the necks walls can be reduced to 0.0085" or 0.009 and tend to be less obstinate. The value to reduce case necks that thin is questionable. Total bench rest techniques in reloading are mandatory to make them shoot well.

The 280 Ackley Improved and the 280 Remington Improved RCBS are basically the same except for shoulder angle. With the standard chamber and neck diameter of 0.318, the factory 280 Remington cartridges can be fired to produce the improved cases. The neck junction is set back 0.004" in the 280 AI chamber for a tight fit when standard 280 Remington cases are fired.

Fire forming will shorten the cases by 0.012" to 0.015". The common chamber dimensions are: base 0.469", shoulder diameter 0.455", neck 0.318, chamber length is about 2.555 depending on reamer maker. I prefer a length of 2.530. This length requires a special fire forming method without a bullet.

Since my chamber has also a tight neck of 0.311, virgin brass is first outside neck reamed. The neck walls are trued to a thickness of 0.0125. Most virgin brass is about 2.538" long. After all the case preparation work is done, the necks are chamfered and the cases primed and charged with 16.0 gr of 700X shot gun powder. The cases are then tightly packed with Cream of Wheat to within 1/8 of top. A dab of Crisco is used to hold the Cream of Wheat in place. Commence firing your cases. You are now ready for reloading.

Most of the time your first full power load will make the case 0.004" longer. I have used both the standard and the magnum primers and have settled on the Federal No. 210M Match Large Rifle Primers. Since my rifle is mostly for deer and antelope hunting I do experiment with different bullets in the 130 gr to 145 gr ranges. The Barnes bullets do a good job on game, but have never produced the best groups in some of my rifles.

My favorite powders for the above bullets are IMR 4350, H4831 and Reloader #22. The Norma cases I use have a water volume of 67.6 gr., filled to neck and shoulder junction. A starting loading density for the above bullets and powder choices would be 85%. Work up from there. Also I have found that IMR 4350 will show sign of high pressure before maximum velocity is reached. I most cases Reloader 22 will reach higher velocities.

Although Norma brass cases are more expensive than domestic cases, the outstanding dimensional consistency of the Norma 280 cases are in my opinion worth the extra cost. I have found that Remington cases are as much as 0.007 undersize and some with more than maximum headspace. Since all cases have to be fire formed the headspace is easily eliminated. But the bulge on the bottom can not, and will eventual allow for primer pocket expansion. These cases were made for semi auto rifles and intended to fall into the chamber.

The 280 Ackley Improved qualifies as an unpretentious 7mm soft magnum. It does not have to take a backseat to any of the medium calibers. The outstanding selection of bullets makes it one of the most versatile hunting rifles. Try it on antelope, deer, moose and elk. The two latter species require the 175-gr. bullets. Also I have killed moose with 160 gr Speer bullets.

With a bullet seated in the case the outside diameter of the case neck is 0.308. The radial chamber clearance is 0.0015" (284+12+12 = 308). Chamber neck is 0.311.

Here are some of the loads I have used and still use. These loads were fired over time in four different rifles and considered maximum in the guns I used them in. This is not a loading recommendation and should not be used in any other gun. Use your case water volume measured in grains to the bottom of neck and multiply by 0.85.

For instance 67.6 gr of water x 0.85 = 57.46 grains of powder for the appropriate type of powder, would be a starting load. The powders listed below are appropriate types for this cartridge.



Bullet Weight
Bullet Make
Powder Weight
Powder Maker
Group @ 100 yards 3 shots
Velocity estimated

140 gr
Nosler solid base
60.0 gr.
H 4831
1.00 inch


162 gr
Hornady BT
60.0 gr
IMR 4350
7/8 inch
2950

160 gr
Nosler Part.
61.0 gr
IMR 4831
3/4 inch
3000

139 gr
Hornady FB
62.5 gr
IMR 4831
3/4 inch
3250

139 gr
" " "
61.0 gr
IMR 4350
-----
------

140 gr
Nosler Part.
62.0 gr
IMR 4831
0.700 inch
3200

140 gr
Barnes- X
62.0 gr
IMR 4831
1.50 inch
----

140 gr
Barns-x
61.0 gr
IMR 4350
3/4 inch
----

140 gr
Nosler Ball Tip
62.0 gr
Reloader # 22
0.250 inch


130 gr moly
Nosler Ball Tip
60.0 gr
IMR 4350
2.00 inch

OTOH we have this....down loaded from another site as well.I'm not sure if this guy is a thoughtful, reasoned handloader or a dangerous nut,and is one reason I regard some 280AI handloaders as a bunch of riverboat gamblers willing to dangle by threads on the brink of imminent disaster....notice the warnings and constant reference to loose primer pockets.

I am caused some doubt about his intelligence and experiences,however, when I see the references to the 280AI being the "perfect" case capcity for the 7mm, and anything from the 7 Rem Mag on up being "overbore"....clearly another guy on a mission.

I know from my own experiences that a standard 280 in a 22"-24" barrel is hard [ressed to hit 3100 fps with a 140 gr bullet....how it is that you can add 300 fps to that velocity and get 3400 fps from it by increasing case capacity to only 67.6 gr in the 280AI has me completely flumouxed(that is stretching the limit for a 7mm Dakota,STW or Mashburn)...and another reason I consider the cartridge to be nothing more than a lot of overblown hype hawked by guys living on the ragged edge of disaster.

Everytime I see one of these 280AI threads I think I should get one;then reason prevails and I know I will simply piss $2k down the toilet and the thing will be down the road in 6 months.

I'm through with this stupid [bleep] topic...and the fools who want to believe this shidt,which is all it is.....







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Ackley Improved User
New Member



USA
11 Posts
Posted - Mar 01 2005 : 15:26:46
--------------------------------------------------------------------------------

This is my 280 AI Oehler-chronographed data with 140 grain Sierra flat-base bullets and a 26" barrel - THEY ARE HOT, SO BE CAREFULL AND WORK-UP THEM FROM 3 GRAINS BELOW MAX IN 0.5 GR. INCREMENTS. STOP! when you see pressure signs.

140 Sierra FB - Alliant Reloader 25
66.0 grs. - 3234
66.5 grs. - 3271
67.0 grs. - 3322
67.5 grs. - 3430 (Maximum!)

140 Sierra FB - IMR 4350
60.0 grs. - 3304 (Maximum!)

140 Sierra FB - Alliant Reloader 22
63.0 grs. - 3241
64.0 grs. - 3300
64.5 grs. - 3318
65.0 grs. - 3342 (Maximum!)

~3400 fps velocity is achievable with a 26" barrel and Reloader 25. But, go no higher and use only first-rate modern bolt action rifles in perfect condition. Subtract ~25 fps for each inch less than 26 inches.



Ackley Improved User
New Member



USA
11 Posts
Posted - Mar 01 2005 : 15:30:08
--------------------------------------------------------------------------------

This post is relevant to Ackley Improved users or proposed users. This post was originally stimulated by a question on another form of "how does Hornady get enhanced performance from their Light Magnum ammunition" - that is, what's their process. Below was my response, but I'd like to get feed-back from the reloaders posting here. What do you think? Besides, I though the individual interested in getting a 280 Ackley Improved might appreciate this post.

I don't know what factory process is used for the Hornady Light Magnum ammunition, but you can equal or exceed their velocities without excessive pressures, if you're willing to tap in powder and use compressed loads.

I have a .257 Ackley Improved (AI), .25-06 AI, .280 AI, and 30-06 AI. All guns are custom made bolt-action rifles (Rem M700 or Win M70) with match-grade 26" barrels. I have developed loads for all by experimenting with almost all available modern powders and by chronographing every test firing (Oehler with three screens). I've developed these loads in conjunction with the NECO Internal Ballistic Program. I have reams of data.

The best performance - at a given pressure for a given weight bullet - is almost always obtained with the slowest burning powder that will fill the case and bring the maximum pressure to the desired level. For example, consider Reloader 25 in a 30-06 using 165 or 180 grain bullets with no higher than 65,000 psi. A standard Winchester 30-06 case will roughly hold 66 grains of R25, when tapped in and the powder compressed by the bullet. Reloader 25 compresses nicely, and with tight case necks the bullet will not be pushed back out by the compressed powder. With a 24 inch barrel, maximum velocity with a 180 bullet will be right at ~3000 fps, and with a 165 grain bullet right at ~3100 fps.

I would NEVER recommend starting with this load, but rather recommend working up to it by starting from 62 grains of R25 - then incrementally increasing the charge by 0.5 grain increments until serious pressure signs develop or you achieve 66 grains.

I'm willing to tolerate "significant" pressure - that is, pressures often used when loading the .270 or some of the newer magnums. (These new magnums look good, because they're being loaded to pressures significantly higher than the older calibers - well over 60,000 psi � even close to 64,000 psi. Hence, the comparisons to the �old� are not fair; remember, the companies want to sell new guns.)

A standard modern bolt-action rifle will tolerate pressures in excess of 150,000 psi; hence, you're not in danger of bursting the gun � not even close. But, you don't want to load beyond 65-70,000 psi, because beyond that pressure you can get a sticky bolt or even a frozen case in the chamber - a disaster, if you need a second shot at the trophy of a lifetime. Loading to 65,000 psi will loosen those primer pockets fairly quickly � although I�ve read that brass cases will �take� up to 80,000 psi without overt failure. (By the way, converting CUP pressure to other measures of PSI is a vague and unclear process, without clear conversion tables or rules.)

To test for loose primer pockets, I hand prime all cases and "feel" the primer into the pocket - indeed, you can consider your brass case a type of "copper crusher" pressure gauge. I don't care too much about multiple reloadings of a single case, because cases are cheap, expendable, and very easy to replace.

Finally, I�ve found that Reloader 25 is the single best slow-burning powder on the market. I routinely get the best performance � both accuracy and velocity � with the lowest pressures. Yet, you must load a relatively heavy bullet. When you go to lighter bullets (e.g., 150 or 130 grain for the 30-06), you�ll may need to use R22 or R19 to achieve maximum desired pressure.

Please keep in mind that the 30-06 AI is only a small improvement over the regular 30-06 - that is, ~7% increase in case capacity. For example, with Alliant Reloader 25, I can tap in ~66 grains in a Winchester case, for a 30-06 AI case I can tap in ~71 grains - both filled just below the top. Then you compress those super charges with a 180 grain Nosler BT, and you'll get ~3000 fps with the regular 30-06 and ~3100 fps with the 30-06 AI. Pressure will be ~65,000 psi, and primer pockets will loosen fairly quickly - maybe only after a few loads. Is this worth it? For me, the fun figuring this out was worth it. But, maybe not for you.

The 280 AI and 30-06 AI are essentially identical in performance - get one but no need for both. When worked-up, as described above, the best load I have for the 280 AI is 67 grs. of Reloader 25 with a 150 gr. Nosler BT, which will produce ~3250 fps in a 26� barrel.

The 25-06 AI is over bore and not much of an improvement over the 257 Roberts AI. Of all of them, the 257 Roberts AI is probably the best - just about perfect bore for the .25 caliber - that is, given modern powders.

Actually, the 280 AI is just about perfect bore for 7 mm caliber - the 7 mm Rem Mag and equivalents are all over bore, in my opinion. The 30-06 AI is under bore for .308 caliber - I believe the 30-338 is just about perfect bore for 30 caliber - that is, until high-energy slower burning powders are developed. I find that Reloader 25 is the best high-energy slow burner out there. I know of slower burning powders, such as H870, but they don't seem to have the energy content.

As a final note, IT IS VERY IMPORTANT THAT I USE ONLY THE BEST COMPONENTS, WEIGH EVERY CHARGE, CHRONOGRAPH EVERY LOAD, ANALYZE MY FINDINGS IN CONJUNCTION WITH THE NECO INTERNAL BALLISTICS PROGRAM, AND SHOOT WITH CUSTOM-MADE BOLT-ACTION RIFLES OF THE ABSOLUTE HIGHEST QUALITY! If you plan to do why I�m doing, you should do the same � compromise nothing.

Regards, Ackley Improved User

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer nor the staff of this forum assume any liability for any damage or injury resulting from use of this information.

Ackley Improved

Bob my friend you kind of just proved my point with the article posted. I get 3315 out of 140's and 3050 with 162's.

So my rifle is doing 50-65fps faster then the authors and I'm using what he admits is a faster powder with less pressure.

Again I respect you sir but that articles matches my claims to a "T"

Good luck.

I might as well put my two cents into this argument.

I am an unabashed devotee of the .280Ackley. Here I should also note that my chamber is the older "wildcat" chamber and not the newer SAAAMI/Nosler chamber.

It is the easiest to load for most unfinicky cartridge most consistently accurate rifle I have ever used.

But it is not a 7mm magnum unless you use top end blue ribbon loads for the .280AI and compare them to the rather pedestrian 7RM factory loads.

A well developed full potential load in the 7RM will outrun the Ackley by a good bit and as the bullets get heavier the bigger the edge to the 7RM.

For my purposes I use two bullets in the .280AI. First is the 120 grain Nosler BT. With 61.0 grains of H4350 I get around 3325 fps and crazy good accuracy from a 23 inch Shilen barrel. Its a near maximum but not crazy hot load.

I have cases that have been fired 10-12 times with no need for trimming or loose primer pockets or any other signs of high pressure even when fired in 95+ degree weather.

Second is the 162 grain AMAX with 58.0 grains of 7828. It is a low to mid-range load that makes 2840 fps out of my rifle's 23 inch barrel. I could probably get another 75 fps or so out of the 162 but I doubt I will bother as the accuracy is so fine and with the high BC of the 162 AMAX 2840 fps will get you a long way downrange in style.

+1

Got the same results as did Accurate Powders ballistician Johan Loubser.

Mallard please do me a favor and don't pull my quotes out of context for the purpose of proving your "point".

What I should have explained but did not take the time to do ( and what I meant) is that Rl22 and similar double based propellants will frequently continue to add more velocity as you add more powder with a corresponding increase in pressure,although you will not see it until you have gone too far....only modern brass is saving you even though you are already WELL over te top...unlike some single based propellants like H4831, which will hit a velocity "wall", and give little to no velocity increases as charges are increased.Your chronograph tells you this is going on with both types of powders.

R22 shares this characteristic with sveral others that are similar...Norma 205, MRP, R19,the old and now gone H205.I have worked with them all and seen this deomnstrated numerous times.

You get away with this crap for awhile, thinking everything is OK,and then one day...POW...I have blown two primers in 40 years of handloading...one with H205 and the other with R22 in the 280.

Back in the 80's a few nuts were using N205 to push 140 gr bullets from the 7x57 in excess of 3000 fps...much the same trash I see among you 280AI users today.So it isn't like any of this nonsense is new;it was junk data then with the 7x57,and this is junk data now..

Anyone with any degree of experiences with the double based powders and similar slow burning single based powders in the same cases know this stuff.

So I did not 'prove" any of your contentions and if you are loading like the second guy whose article I posted all I can say is good luck to you....you're one of the 280AI loaders I'm talking about.

To me a 280 A.I. is nothing more than a 280 with the advantage of vastly improved case life and reduced both thrust. The claim that A.I. cartridges mask pressure signs intrigues me not because I intend to run more pressure but because it tells me that the chamber design does not have week points in which the pressure is concentrated causing case distortion or failure at a sooner point in the life of the case. It's kind of like the difference between buying a vehicle that is a 50,000 mile throw away or a 300,000 mile marvel of good engineering. To me....engineering that increases the life of the machinery is a good thing. The engineering behind a straight wall case with sharper shoulders is in fact a very basic and simple engineering concept. In fact the principles involved are so simple you could call it stupid simple!

The claim that us A.I. owners are running excessive pressure is nothing more than a lying line of presumptuous BS. I guess we are supposed to buy and use pressure test equipment to load to pressure tested manuel loads for our 280 A.I.s even though 99% on this forum dont including Bobin Not Home! I'm getting tired of the lying presumptuous BS!!!!!Of course there are ones who will push the envelope from every caliber and make but this is not somehow mysteriously centralized to 280 AI owners. BOB....YUR FULL OF SCHIT!!"

Genius: I (use the term loosely)....along with straight tapers and sharp shoulders that don't stretch,we find finicky feeding in some rifles;high pressure that "seem" OK at home in (say) Illinois,could leave you stuck in the field with a jammed rifle when the temps hit 80 degrees in New Mexico or Africa.

The more tapered case extracts more easily due to the design of most bolt actions along the lines of the Mauser 98 types, primary extraction as you lift the bolt handle causing the case to pull away from the side walls of the chamber as the bolt handle is lifted...not so in a straight taper (Ackley design)as the case drags and sticks to the chamber wall,causing less reliable extraction and function.

The Brits and the inventors of the 7x57,the 30/06, the 270, and the 280,375H&H,300H&H all knew this stuff about bolt action rifle function, which you clearly "don't".

Of course you wouldn't know any of this because you don't know much except what you "read",are an idiot,and have little to no hunting and shooting experience.A treatise of what you"know" will fit on the back of a postage stamp,single spaced.

I'm still waiting to hear all your 7mm "experience" of which I suspect there is very little.

Go sit in a corner,junior.You know next to nothing...you're just polluting the bandwidth.