280 AI: SAAMI chamber or not???

With the 25-06 AI I built, (almost the same case just smaller neck) standard factory loaded rounds chamber with just the ever so slight touch when the bolt is almost fully cammed down. Other than that there is hardly any noticeable difference between them and how fire formed loads chamber.

When I do form brass I simply neck up the standard 25-06 cases using a 270 expander, or neck down 30-06 cases. I leave a false shoulder on them that will just allow me to close the bolt with a little bit of interference. Once the trigger is pulled out come fully formed and fitting cases.

When I was having mine built I corresponded with several gunsmiths who were building some very fine rifles, and one friend who was there in CO and worked under PO himself.

All of them mentioned be sure that the headspace is set using a "GO GAUGE" as the no go gauge, and not the no go, and this applied no matter what the caliber. To make a GO Gauge you used one that had been ground .004" shorter. This would allow any factory load to be chambered and held tight when fired, to allow for forming. If it was to be a re-chamber of a factory barrel, then the barrel also has to be set back enough to allow the reamer to cut the new chamber properly.

Here is a good read about it if your interested,
Rechambering for the Ackley Improved

I have the 25-06 as well as two Contender barrels chambered in .223 AI, and 30-30 AI, and all of them are set up the same way as mentioned above. It is not an issue to fire standard factory loads in either, and if done properly there is no loss in accuracy. With the Contenders, they will both shoot factory loads sub MOA with everything I have tried.

The mention of Nosler 280 AI brass and loads, is something I have run across several times before and in some cases it has been mentioned it wouldn't chamber properly. I can't say one way or the other, as the only .280 I have I left alone, due to having a 7mm RM and STW to go fast with.
 
This a Manson Reamer on chambering the Ackley

http://www.mansonreamers.com/Instructions/Ackley Gaging.pdf

I had 280AI building using SAAMI spec reamer and I didn't build it to fire form brass as I plan on buying Nosler 280AI brass. If I had to fire form brass I would of had one build like Manson post and used 280 case like my other Ackleys.

I read couple post about the Cooper 280AI on another site think it was last year. If I was going to buy a rifle I'd buy one that is chamber for the 280AI SAAMI spec. I've shot the old 7mm Express and my 280AI was Rem 700 280 and like the 280 case.

Well good luck
 
Kimber chambers a 280 AI using the SAMMI spec. I read about Sako's in this caliber but can't find where they have one in their product line so they remain an unknown. Regardless, it seems the industry is moving toward the SAMMI spec so I've decided, very reluctantly, to not get the Cooper.

I still do not understand why Cooper is staying with the old version of the caliber, regardless of which is better, since the standard now exists.

This caliber is getting more popular and sooner or later more cartridges will be produced for it; they will all surely be made to the SAMMI spec.
 
You do handload, don't you
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Of course I hand load. But I can hand load for either the new SAMMI standard or the older (albeit, more established) standard. Performance should be identical so why not chose the now-accepted standard?

We can argue until the cows come home whether SAMMI should have changed the old, established "standard" but they did and I don't see that changing.

I still don't see why Cooper doesn't change...
 
That's all true but I just don't see why it matters to the handloader.

I'm not arguing that A is better than B or the other way...

I'm saying, it don't matter. Buy the GUN you want. The cartridge is irrelevant.
 
Datoka arms is owned by Remington and they make 280AI might want to read about it.
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I had overlooked Dakota (and Nesika). I just called and they also chamber their 280 AI to the SAAMI standard.

Yet another reason to go that route...

The Dakota and Nosler Custom Limited are in the same price area. Would one be preferable to the other with regards to assured accuracy performance??
 
i dont want to sound negative,disrespectfull or like a troll.the 280 AI bullisticley indenticle the,7mm rem. mag and 7mm WSM. if anything the difference is trivial and gun companies come up with so many new cartridges every year that have differences that are trivial at best from the old guns as a gimmick to get people to buy new rifles.wild cats alike are often created more for the imusement of gunsmiths then any real necesity

why even worry about getting such a rifle.almost all of the ackley and layne simpson wild cats are obsolete and irelivent.
i am not trying to be rude,why not get 7mm WSM
 
Not really. It's a smidge less than 7 RSAUM, which in turn is a smidge less than 7 WSM, which in turn is a smidge less with 7 Rem mag. These are small smidges, but they're there. Below .280 AI, .280 rem and .284 win are about on a par.
 
FLChinook, The Dakota is going to weight more looking at both spec and it's in the barrel, Dakota 280AI using Lilja # 5 contour. Depending scope/mounts it be about to 10lbs about 1lb more than the Nosler. I like the Lilja barrel got one on my 280AI it weights 9 3/4 lbs.

Well good luck
 
thats what said or at least meant.the differences between these guns are not worth worrying about.

i would put the .280 AI more on par with the 7mm mag than the classic .280 or .284 win
 
Since I started this thread, I'll attempt to provide closure. We started out asking the question of which version of the 280 AI is preferable. I'm responsible for expanding the scope by asking for input on which rifles might be better (now, there's a can of worms for you!!). Others have questioned the need for the AI version at all. This was all very useful and thanks to all who contributed.

First, and while there is not agreement on this, I have decided on the SAAMI version. As Brian Pfleuger pointed out, when you reload, it really doesn't matter. This is true but is does seem the industry is moving toward the standard (except for Cooper, grrrrrrrr) and using the standard means I can reload or buy.

Regarding the need for an AI version at all. Green_MTMan is absolutely correct in that there are many more calibers out there than the shooting world really needs. Remember when the average shooter only had to worry about choosing between a 270 or a 30-06? But there are special situations that allow someone to indulge. In my case, I've had three rotator cuff surgeries on my right shoulder and every ft-lb of recoil is of concern to me. I know, I can get a suppressor but I do 99.9% of my shooting at the range and I hate the extra noise. That's me.

According to Chuck Hawks Rifle Recoil Table, the recoil of a 7mm Rem Mag varies from 19 to 22, depending on bullet weight. The 280 Rem is around 17 with a slightly lighter rifle. Assuming the 280 AI is similar to the 280 Rem, it will recoil about 20% less than the 7mm Rem Mag. And the performance is about the same. All of you who regularly shoot unbraked 338 Win Mags at 34 ft-lbs will scoff at this distinction and I yield to your physical prowess.

So for me, it will be a 280 SAMMI AI. It could be just a 280 Rem but I might as well go as far out the performance curve that my shoulder will allow.
 
Hey, if you're happy with it, that's all that matters. :)

Much like my .243AI instead of the Win. Is there any real world, significant reason? Nope, just splitting angel hairs with the head of a pin.

It's just what I wanted, so I got one.

You want it, get it. Be happy. :)

We will expect pictures and a range report though. ;)
 
FLChinook, I wholeheartedly agree with get what you want for YOUR needs, and go have fun. That was why I had my 25-06 AI built. I already had an extraordinary standard version which had done everything I ever asked it to do. I simply wanted something a bit different and with which I cold bump up the velocity on the heavier bullets with. I built it from the ground up to do that.

There are a few who have commented on how well they liked it and a few who didn't like it at all. But after the dust settles it still comes home to my barn to sleep.
 
FLChinook said:
So for me, it will be a 280 SAMMI AI. It could be just a 280 Rem but I might as well go as far out the performance curve that my shoulder will allow.
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I've never fired a 7mm RM, just the .280 AI, I love it but it does have a thump to it. Part of the problem is the gun weighs somewhere around 5 1/2 lbs, my own fault. That being said I wanted a very light rifle for backpacking and that's what I got. I'm currently working with a custom builder on getting a brake installed.

The ballistics on this cartridge are great though, sure I could have gotten something more mainstream but I always enjoy something a little different.

Hope you enjoy your new rifle, did you land on a make/model?
 
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