I have a military Mauser 98 that has to become a sporter.

I have considered the 338-06, but one of the chambering reamer rental shops has the 338-06 Ackley improved available.

So is there any reason to consider using the Ackley improved round?

Nope as long as you handload. Might not feed quite as well and most Ackley cartridges really don't add all that much anyway.
(Duck, incoming!) Resale (if an issue) will suffer too.

If you want it, you should have it. After all, the Yellowstone Caldera is overdue to blow.

One reason, it could clean up an existing chamber. I did that with a 308 barrel when I turned it into a 30-06 AI. A standard 30-06 won't clean up a 308 without a serious setback and shortening of the barrel.

Some will say it will help prevent excessive case stretch prolonging case life.

It does have a cool factor.

Not much of a volume increase (338-06 AI vs. 338-06), thus, not much velocity increase - assuming equal pressure levels.

One potential problem, if you ever do some big dollar guided hunt, is the name.

By the time you've told your guide what you're shooting - three thir-ty eight ought six ack ley im proved - the record book animal you're looking at has escaped into the next county.

Better make it a two eight-y.

More trouble than it's worth. I had a 338 Scovill (a 338-06 Improved modeled around a 9.3x62 case) built on a M70 one time. I did not get enough additional velocity out of it over a 338-06 to make it worth the hassle in case forming.

Improved cartridges are a nice idea, but after fooling with a couple, if I wanted more punch than a 338-06, I'd go to another cartridge - 338WinMag, 9.3x62, whatever hits your fancy. Spend more time shooting & less time case forming.

Only my thoughts, but they're yours FWIW

Mines not any faster, but does have the cool factor.

No hassles really in fireforming. New brass in any chambering I run through a die to straighten 'em out anyway, so necking up 06 with a tapered expander is no extra effort. Fireforming is good for much needed practice also. Not that big a deal in the overall scheme. I'd do it again.

I went back and forth on the 338-06 and 338-06AI. I wound up going with a standard 338-06 because of the standardized caliber and commercial ammo versus handload only. I do handload but if I ever decided to sell the rifle my target audience would be limited to handloaders.

My 338-06 is currently being made/barreled at Pac-Nor and I hope to have it later this fall.

I have the 338-06 Imp on a model 70 classic. It feeds very smoothly so, at least in my rifle, compromised feeding is not an issue.

The supposed hassel of fireforming is another complete non-issue ... you do practice with your rifle, do you not? Two birds with one stone and all that.

There is probably less case stretching with the improved version but that really is another yawner. If you are too lazy to trim every few firings, you are probably too lazy to handload well.

If you find yourself in a situation where you have to use standard factory 338-06 ammo (good luck finding it) than go ahead and use it. The accuracy in my rifle suffers not at all when fireforming and velocity loss is negligable. The worst that will happen is you will end up with more fireformed brass.

You will realize a velocity gain of maybe 35 to 40 fps if you do not lean on things too hard. This is a negligable gain in the real world but it does seem to fall under the category of "free lunch".

The only issue of consequence is, I believe, having a gunsmith who is competent enough to see that your rifle feeds propery.

Do what ever you want and sleep easy after the fact - there is no wrong choice between the two. In either case you will end up with an easy to load, easy to shoot and extremely potent big game getter.

The fact that an AI cartridges has much lees case groth is a plus IMHO that allows the brass to last much longer. Triming cases after each firing simply means that the case head will soon seperate

Before I commissioned the build I would read Ken Waters' article on the subject. He did an excellent article in the pages of Handloader magazine.

You can thand me later.

The 338-06 Ack is my favorite Elk cartridge. I use the Swift 210 Scirocco with Rel 15 .

I don't see any advantage, and I like AI cartridges. The bigger the diameter of the bullet the less gain there is, except of course the lack of trimming and "cool factor".

I have a 338-06 A-Square and LOVE it. You get near WM performance with less powder, and cases are easy to form. I used old 270 WCF stuff a client had given me.

If you have a hankerin' for an Ackley may I suggest the Better Bob??

I once read that the .250-3000 Sav is the greatest of the AI improvements.

I replaced the .30-06 barrel with a .338-06 A&B on my NIB Sav 111 laminated stock and I wouldn't even think about touching it.

I played with a 338-06AI for a bit and didn't seem to get any noticeable velocity advantage over guys loading the non-AI version, "maybe" 50fps... and hassle with fireforming etc.

Sold it on here a while back - hope "Savorino" has coaxed a few more fps from it-

More trigger time is a real pain in the ass.......

Actualy I've found fire forming to be a great way to enjoy a new rifle. My 257 AI shoots fireforming loads nearly as accurately as full-powered ones.

Only Ackley chambering I have is the .243AI. I agree with previous posters in that any velocity increase you'll see with your .338 will be minimal but case life is extended noticeably. I base that conclusion on the fact that my case trimming has become a non-factor. Fireforming and load development are a pleasure in my experience. Only down side I can see is a hit to it's re-sale value or market appeal. Just not a popular chambering.

Also built a 338-06 AI on a 98 action with A&B short chambered 338-06. Shoots MOA but not much velocity gain. Get 2700 with 210 TSX. Would probably do it again. I use 270 brass but fire form with 12 grains of bullseye under corn meal after trimming to 2.5".

AI in this case,was great idea,just enough extra volume to use H-4350 with a 225.Lower pressure,but the same 2650. Some of the newer mid-range powders such as Big Game,my choice, N-550,and IMR-4007 makes that less of a reason to AI.

R-17 might be real interesting.

Just AI it and be done.. there is no downside... ..

And +10 on the RL-17..

Croldfort,
Ackley claimed the only cartrides that satisfied him in his Imp line of cartridges were the 250 Savage, 257 Roberts and 7x57, these 3 gained about 300 FPS and that is a substantial gain.

As to the 338-06, and from a practical hunting standpoint there is little, if any advantage to improving it..But, I would suggest there might be some advantage to case life, another 100 ot 150 FPS in velocity, better head spaceing and less case trimming as the IMP cases are alleged to streatch less and I think I agree on this, and one probably has more room for his bullets and if you have a long chamber and magazine then you can add even more velocity, all the same ole stuff, and it has some merit, but at the price of time and effort.

I wouldn't expect any better killing power as there is plenty to spare in both..

In my opinnion, and I shot the 338-06 in both std. and IMP. early on, the best way to improve the 338-06 is to rechamber it to the 338 Win.

The 338 Win. walks off and leaves the 338-06, it does not have any more felt recoil that I can tell, it works out of the same size action, if you want 338-06 performance then use less powder in your 338 Win. It really improves on the 338-06 IMO and in the same rifle..At least that has been my experience and Elmer Keith agreed with that.

I can push a 210 Nosler at 3005 FPS with little pressure, and a 300 gr. woodliegh at 2500 FPS, that is way beyond a properly loaded 338-06.

I have no problem with the so called dreaded "belt" for you belt bashers, it's been working on the 375 H&H, 300 WBY, 416 Rem, 7 MM Magnums for 200 years, and with honors.

If I wanted a non belted 338 then I would go with the 9.3x62 as the best bet..Whoops I have one of those also.

Not bashing the 338-06 or the 35 Whelan (same catagory as the 338-06), they are both definately good cartridges, just that IMO there are a couple of better options out there for your consideration.

Had and love the Standard NON-ai. Would never do one in AI.

Case stretch a non issue. Performance too similar IMHO.

Throat a Non-Ai for 250s to max case capacity and still touch lands if desired w/200-230s - those will do most anything asked of the 338 bore IMHO. 250 and heavier are fine also, but trajectory can be an issue.

IMR4320/WW cases/partial sized brass after simple neck up and firing worked great.

1/2MOA

2900+ w/200s
2790 w/215s
2670 w/225s

23" Hart

I have both the .338-06 and .338Win taking up space in my safes. A .375H&H lives in there, too. I don't shoot anything bigger than whitetails and the .308Win get my nod there.

FWIW, one of my elderly local gunsmiths used to drive to AZ to shoot long range. Mayap 900yds. IIRC, his rifle was a custom .30-06 AI loaded with 190 gr bullets.

He had two old German Schuetzen rifles with hand carved stocks that were an absolute work of art. I would make him drag them out from the back of his house, just so I could admire them. Life is good.

I have a 257AI and 7X57AI and love the "improvement"!

I once owned a 30-06 AI and found no earthly reason why, after fiddling with it a lot.

I tend to agree that not much is gained in the bigger tubes, however my FN rechambered from 375 H&H to 375 Wby gains 100-170 FPS.

Well okay, I'll bring it up long as no one else has. In Nosler #5 the 338-06 A-Square has a Max SAAMI OAL of 3.440" . One would be damn hard pressed to get that length in a 98 unless you plan on a major magazine job. My FN lets me seat a 200gr SP Hornady in the middle of the cannnuelure with a 2.484" trim job for an OAL of 3.332" and that is to tight. If you don't lengthen your magazine you have to short seat the bullets and how does that add to your case capacity? So buy a M700LA and rebarrel it to cash in on the 3.6"+ mag length. Hey build it to shoot, not swoon over. You asked for opinions,I gave you mine at no charge.Magnum_Man

I've got a .338 AI in the works right now. The barrel, a 24", was given to me, so I ain't got a nickel in it. I don't want to open up the bolt face and fuss with feeding, so I won't go with a magnum. I reckon I'd get better speed from a 26" tube, but apart from the many nickels I'd have in it, it'd be a bit unwieldy. Pretty sure a bear won't be able to tell the difference...

I've owned a few rifles chambered for 40-degree shoulder improved cartridges and don't recall that any of them fed as smoothly as the original case prior to being improved.

The worst feeding improved cartrisge that I had was a 250AI in a Ruger 77 RSI. It fed so poorly that I got a new 77 RSI 250 Savage barrel from Rody's and rechambered it to 25 Souper. Same performance, better/smoother feeding.

I have a 338-06 built on a Husqvarna action that was intended for shooting elk and moose size animals, big enough that I want to be able to take quick follow up shots for as long as the animal is still standing and the shot(s) aren't obstructed.

A nearly 11 year old thread resurrected. Nice.

Are you sure ?????????????

Sure it's nice or sure it's nearly 11 years old?

even on an 11 yr old thread. I have one on a Model 70 action.... and compared to several friends who have the AI version...
mine is more accurate ( done by one of the last guys to train under Ackley, who recommended not going with an AI version), plus mine gets 50 to 75 more Fps MV, that 3 friends AI's get....

YMMV...

But I took Bob West's advise and glad I did....he may not have been P.O. Ackley, but training under him, is about a close as one could get...

NONE. Unless paper ballistics impress you.

NO.....unless you like spending more for dies and suffering more on resale value......and gaining nothing for it.

AI cartridges are a great way to spend money and have cocktail hour yarns for a little extra performance. Ymmv

I have owned a bunch of Ackley Improved cartridges over the years. I have a 280 Ackley now, only because it was a new factory rifle at a good price. Overall, they are not worth it. Wasted components when fire forming, barrel wear doing same, and all for little gain. I am past the "Gee Whiz!' stage now.

With components being in short supply nowadays, just about "any" round is going to be costly. If one has a good supply of them, then hey, whatever a man chooses is OK. I would not do another AI myself, just because of that, and Time is a premium anymore. But I do like how they "look" , ha.

I really like all of my Ackleys, but I tend to push them hard. The 338-06 Imp. is 30 this year, so predates the A-Square. A stainless A-bolt stalker with a 25" Shilen select barrel. It only has a 1.5-5x scope, so not the best rig for shooting tiny groups, but adequate for 300+ yd on deer size animals. No feeding problems at all as long as I stay under 3.4" OAL. CH made dies for my chamber at a reasonable price. Get the tapered expander as an option or add-on. There has been about 820 rounds down the tube so far including F/F. The Teslong shows no ugliness anywhere in the barrel. I still have the unfired factory '06 barrel that will screw right back onto the gun. It really doesn't matter, but will someone please explain why the resale value would take a hit?

No standard 338-06 to compare it with, but I can reach 3000fps with 200s & 210s with a casefull of H4350 & between 1/2" to 1-1/2" 4-shot groups @100yds. Mostly under an inch. For comparison... this is approx. 8-10gr less powder than a 338 WM uses to get the same speed. Big Game is also showing promise. Two different lots of RL17 didn't quite get it accuracy-wise in my rifle. Speeds were up close to 3000. Hornady 35 Whelen brass is on the 5th or 6th full power firing. Primer pockets remain tight. I've used 280, 30-06, & the Horny 35 Whelen brass so far with success. With past lots of brass, it rarely needs trim after F/F (to square mouths). The rifle was built specifically for the 210 Partition & I can see no reason or need to shoot anything heavier than 215 Sierras, or maybe 225s at 2800+ & 2600fps respectively in very limited testing so far.

Nothing needs to be "wasted" during fireforming. If you're that damned cheap, I wouldn't hesitate to take it deer hunting around here with F/F loads. Of the last 25 I formed with Speer 200s & the remnants of an $11 price tagged can of IMR4895, 18 shot into 1-1/2' @ 100 yds. at 2764fps 10' instrumental. The 2 flyers opened it to about 2-1/2". The last 5 rang a 6" steel plate at 200 yds. with a 1" high 100 yd. zero. Range notes say it was, not windy, but WINDY that day. Not too shabby for a bunch of leftovers.

358WCF,

Pushing Ackley Improved cartridges "hard" is the primary reason they supposedly get significantly more velocity--and always has been. Only a few Ackley Improved rounds get 100 fps more muzzle velocity when loaded to the same pressure--and those are older cartridges with far more body taper than the .338-06, such as the .250 Savage. In most cartridges you can get within 50 fps of the same muzzle velocity by pushing them hard.

I have fooled with a bunch of Ackley (and other "improved") rounds, and so far the only significant difference I've found is the near elimination of case-stretch--which saves a lot of time in reloading hundreds of varmint rounds, but not much in big game cartridges. That said, a lot of recent varmint rounds have a sharp enough shoulder to result in essentially the same thing.

But whatever.....

I have the AI versions of several (including the 338/06AI) and I mostly like them because my fired brass management isn’t good and I like to quickly ID my brass and I neck brass up and down so head stamps alone don’t always work

Except my 223AI, while it’s nice to quickly separate that brass from say my AR15, I shoot heavier bullets in it and try for every FPS I can get.

John,

Maybe "a bit" would have been better used than "hard". Either is an precisely inexact term. Like I said the newest brass still has tight primer pockets after 5 or 6 firings right about 3000fps (c.2985 instrumental Oehler 35 center screen @ 10'). I had some WW brass that had 12 firings before it retired, but that was also used in load development so was past the point where I stop now at least twice. Unsure how much speed the 25" barrel adds. Maybe 25 to 35 fps/inch? Negligible over a 24", but noticeable over a 22". Was going to cut it back an inch at a time after a good load was found to see how many fps were lost, except the rifle balances & handles well as it is. The loads have been trouble free after some initial teething pains. If you were wondering, nickle 280 brass cracks at the neck/shoulder within 3 to 5 reloads after fireforming, but looks cool as schidt with CT Ballistic Tips. It's the same with my other Ackleys. The '06 has a 26" barrel & knocks on 300 H&H speeds with 150s to 180s. The Roberts was 26" & came near 25-06 speeds, but got sold. The 22-250 is only 24"... for now, but betters any 26" Swift I've ever had. Brass life is beyond good with all, but I run them close to red line because that's where they seem to group best. A win/win it seems. Yes I did read most of Bob Hagel's stuff, but tempered it a bit with a lot of Ken Waters.

Now about pressure... equivalent of what? It's certainly higher than a factory '06 & so far, less than problematic. I have no pressure equipment other than a .00005" micrometer & a chronograph, so I bow to your experience with actual pressure tested loads. If the brass lasts as long, or longer, than the same brass in a regular factory chamber with plain old regular loads below "book max." (think 50-52 gr 4064 in WW brass with a 150 in the '06) it makes me curious how unsafe it could really be. Are there really +/-10% pressure excursions with carefully prepared handloads showing SDs often in the teens or lower? Thanks-358.

Never had the AI in 338-06, no need with a 24 inch barreled 338-06, H-380 powder, and 210gr partitions at a 1/2 moa accurate 2800 fps, save the throat, component cost and time, neck up 30-06 brass with one pass, load, zero, and go hunt.

It's a great cartridge, haven't fooled with big bears of the great white north either, but wouldn't hesitate to do so with 250gr A-Frames at 2525 fps over RL-17, or any other critter that inhabits that big spot on the map.

Compares favorably with the x62 in your opinion?

I have been saying this for 15 years now: 338-06 ballistics are an ideal mountain rifle set up in bear country.

Make that longish shot on the sheep or goat through 30 mph winds with a sleek 200-225 grain bullet.

Drop the scope and hike out with the magazine loaded with 275-300 grain bullets sighted to the open sights. Middle of the night, when a curious bear comes to sniff your pack full o bloody sheep meat, that rifle will feel just right in your hands........

Haha. Truth.

To add -

I’ve got several 338-06 rifles and love them. Never tried the AI but can’t see it doing bad things if even limiting the case stretching & maximizing brass life with no other gains might be a net positive.

Stack up a bunch of 200gr Speers & 210gr NP and even several 250gr NP because you can - you’ll be set up for about everything.

In agreement with Atkinsonhunting. There does seem to be a difference (to me, at longer ranges) between a 338-06 (in any of its versions) and a 338 WM or in my case a 340 Wby. I really like the 338-06 almost to a level that some might call excessive - but - it’s not a 340 Wby or a 338 WM. Those two rounds just seem to stomp stuff like they should be illegal especially in the long range penetration department.

My goodness - I don’t know how to express how great a 250 grain Nosler Partition is - and I know there are other, better bullets that I don’t have experience with but I can’t imagine more of a reliable bedrock, simple, at all cost performer.

All of this is my .02 and I’m not a gun writer or professional in any way but have killed lotsa stuff with lotsa stuff.

Is a 338 06 AI practical? Nope.

Any real advantage over a non improved 338 06? Nada.

But I like it. And that sharp 40 shoulder looks cool.
😁
And NO ONE else will have one in an Alabama deer camp. Hell, most people give me a puzzled look when I respond to their questions about what's I'm carrying in the woods.

And it HAMMERS Alabama critters with a 200 gr SST at 2875 FPS.



For something really impractical, I also have a 35 Whelen AI. Mule Deer has called it the most useless AI cartridge.

Practicality? Meh...

I think this thread is a good example of why resurrecting an old thread for more discussion is not necessarily a bad thing.
i have two .338-06 (standard versions) and a .35 Whelen AI. The Whelen feeds very smooth in its Mauser action with no mods (was born a Husky M98 30-06)
Do whatever you like on your build. I think the AI is cool, even though neither of mine is an AI. The basic .338-06 is great too and you'll love it as well.

Best of luck,
Rex

You might as well have an AI - it’s not like the normal 338-06 is that normal.

Then there's the 338 RCM PRC LMNOP on the short action. Mine holds 4 down, weighs 6lbs 8 oz without scope. Equipped with good open sights, its turn key from the factory. Only thing I did was sell the synthetic stock and ordered a walnut stock from Ruger.

60 grains of reloder 16 under a 225 grain Federal fusion is what I'm running.

Depends of what you may see an an advantage.

For use in the field killing game (the intended purpose------ unless the purpose is making the "numbers higher" to impress yourself) the simplest answer is simply "no.

Not sure why he says that, Volume increase isn’t that much less than a 280 AI percentage wise.

Granted, it’s really about the pressure difference of the reloaded rounds !
Supposedly, the AI doesn’t show pressure signs as soon.

For me, I haven’t decided if spiral bolt fluting is a real functional improvement , or simply an affected style feature.

338’06 Go your own way : Alaskalanche built a beaut off of an 84L Montana ‘06 rebored , with a 20” barrel.
A thing of beauty in the bush.

Others go with a longer barrel, and the AI gives more combustion chamber and less trimming, to take advantage of it.
338-280AI takes it to a fairly practical limit using standard brass.

Some have used the 280 RCBS for the optimum shoulder angle for combustion and a little easier feeding after necking up to 338. I can’t see much real difference their over the AIs 40 degree shoulder, but some folks are willing to pursue that compromise especially in a crf action.

4 or 5 down doesn’t hurt either.

I like ‘em both

338Rules,

Hmm. Are you saying any tiny difference in velocity and, perhaps, accuracy makes a noticeable difference in "killing power"?

Sorry, but could not resist. But if you LIKE it, why not?

It’s all about the “Panache” !

As I get older, and so much maturer, I am starting to realize that “Killing Power” has as much to do with Accuracy, as Initial Velocity , Ballistics of Drop & Drift, terminal velocity, and finally terminal impact performance All Combined.

Thanks for not resisting !

Cheers

Yes it is. 👍

Got the left hand blued/wood version of this. It smacks thing hard. This is the real Improved version of the 338 as it has nice proportions, has irons on it and handles wonderfully with its 20" tube and short action. It's been the best rifle I've ever had to date and it's closeout price of $499 NIB was a steal.

My AI was strictly a good rifle deal I couldn't let get away... On the receiving end definitely no advantage I can see...

Nice old thread. I agree with this ^^^^^^.
Doing it on a Mauser will cause some feed issues either way and mag box length issues either way. Both can be over come.

AI cartridges give plenty of benefits:
- increased velocity
- increased efficiency
- reduced brass stretch
- reduced bolt thrust (very good for a military Mauser)
- better headpace (and likely improved accuracy)

I doubt I would build a rifle in .338-06, but if I did I would definitely do AI. There really is no downside.

Woody! Good to see you on the 'fire... and HAPPY BIRTHDAY BUDDY! Hope its a good one....

some of us miss ya around here..... one of the good guys, we've been sorry to see ran off by the idiotic Trolls...

Have a good hunting season my friend....

Myself... I'm thinking this may be my last one...

Not only NO....but hell no!

Back on topic.....

I built one.. on a Model 70 action, rebore...The guy who did it, was one of the last guys to train under P.O. Ackley. Bob West in Eugene OR.

When he did it, he told me old P.O. Ackley saw no reason for it, because it gave no real world gains... so I just went with the 338/06 rebore.

Had several local buddies with the Ackley version... and at the range a couple of time, each with 24 inch barrels., mine had 50 fps more velocity than the guys with the AI's. so that kind of bore out what Bob West told me P.O. himself said.

He also was the guy who recommended to use H 380 for it, which I followed and it was a right choice... that or 4064...

He recommended 50 grains of 4064 as a charge for it also.... because the velocity for 200, 225 and 250 grain Hornady bullets was 2500 fps MV, with that 50 gr of 4064 charge. My chronograph verified that also... and also pretty much had the same general point of impact at 100 yds.

and here is Bob West , operating out of his garage. who had about 20 guns he was working on for Hank Williams Jr, about 10 for Tom Selleck and a host of others for celebrities......While I was at his shop, Hank Williams Jr called him like 3 times, so he finally took the call, when I said I didn't mind waiting.

Then all of a sudden, he says " Hank, I gotta go take a Whizz.... here talk to my friend John here, until I get back.." Then he just hands me the phone and takes off..... So I hear Hank Jr on the phone... "hey John, how's your day going?".. so I talked guns with Hank Jr for about 10 minutes, until Bob got back..

Hank had asked me what Bob was working on for me, and I told him the 338/06.... well that's a good caliber....I prefer the 35 Whelen.. but I've seen them on some of my hunts with others, and they certain work on Elk and Bears....

For a celeb, old Hank Jr was a real down to earth guy..... so my 338/06 has some sort of pedigree to it... kinda sorta...

Nice story. What was Magnum, PI shooting?

Cool story, Seafire!

Cool stuff Seafire... Bob West built my 338-06 also way back then...25 Inch Donnelly barrel on a 1948 pre 64.. Interesting for sure although I didn't get to talk to any celebrities'.

Who's Hank Williams Jr?

Since 1975 the .338 Winny has performed wonderfully for me on Alaskan game and the 30-06 has done the same thing since 1965 and a .338-06 worked also, but has only seen limited use. I have recently turned a new production Mod. 71 into a .348 Ackley Improved and if I get close enough I expect the wonderful 250 grain Kodiak Super Bonded Bullets at about 2,500 fps mv to work very well. Do I need an Improved .348, probably not, but I sure wanted 35 Whelen ballistics with a 250 gain bullet and the improved .348 Ackley version gives it to me. So the itch is scratched and I am happy about it.

The Deluxe Mod. 71 rifle has a beautiful walnut checkered stock, beautiful bluing and I will be feared by all beasts when I am carrying it. Once the XS receiver sight is zeroed for 150 yards all range shooting will be shot off of the sticks. I will be the envy of everyone and I will also look good with my Filson Packer oil skin hat, heck ya!

One thing they all have in common, if the right bullet is put in the right place at a reasonable distance they all kill well.

Does a 338-06 Ackley make sense, not to me because I don't want one, but if I did.........

I have not read all the responses. But I had a similar problem when I picked a 375 Whelen AI. It was what the reamer rental place had and the die retailer had. So I went AI.
The problem is the controlled round feed of the Mauser requires a bit of work on the rails and feeding ramp.
I also have a 280 AI on a 700 action. With that action there was no need to alter the feed.

I'll say the same thing I said in 10/10 if you want whatever performance increase in an AI over a std cartridge. Atleast put it in a std length action not a short box mauser 98 (3.25"). Mb

Do you find , while case trimming is much reduced, that the neck / shoulder junction will thicken over many cycles?
This is what I have found with a 6 Dasher and 280 ai. This makes closing the bolt a bit harder than normal , so neck turn the base of the neck.
Improving a cartridge is not about velocity (for me), but getting it 'right sized' to give more opportunity to hit an OBT at reasonable pressures.

[/quote] Do you find , while case trimming is much reduced, that the neck / shoulder junction will thicken over many cycles?
This is what I have found with a 6 Dasher and 280 ai. This makes closing the bolt a bit harder than normal , so neck turn the base of the neck.
Improving a cartridge is not about velocity (for me), but getting it 'right sized' to give more opportunity to hit an OBT at reasonable pressures.[/quote]

I have seen that--but it also can happen in non-AI bottlenecked cases. But have also seen it in brand-new factory brass with relatively sharp necks, say around 30 degrees. Had a batch of new 6.5 PRC brass that apparently had the "dreaded donut" to a certain extent in maybe 10% of the cases, because it showed up after the first firing. Like you, I neck-turned the base of the neck to solve the problem.