Fireforming .280 AI from .280 Remington brass or .270 Win brass?

[Alibiiv]

I saw this Video and It is flawed. When you chamber the 280 Ackley or the 280 SAMMI AI It is true that you can use the same reamer. "BUT" If you use the different head space gauges you will end up with different chamber lengths.

If you understand the relationship of the two and use the chamber dimensions of both (According to SAMMI) the body neck junction on the 280 Rem is 2.1924 from the case head. The 280 SAMMI AI body to neck junction is 2.1742 Making the chambers after fire forming .0182 different. with the .004 to .006 compression of the Ackley recommendation this will reduce the difference of the two chambers
to .0142.

Obviously, If you use the SAMMI head space gauge for both chambers, It will be a SAMMI 280 AI chamber but you may not be able to chamber a standard 280 Rem cartridge because it will be at least .014 thousandths long.

If you chamber it using the 280 REM head space gauge as Ackley recommended and try to shoot a Nosler 280 AI formed case you will end up with .014 to .018 space in front of the body neck junction and possibly have case head separation.

The Body taper per inch is just over .008 thousandths per inch on both cartridges so they will appear to head space the same but the shoulder will be located .014 to .018 different between the two.
So when you fire a Nosler SAMMI AI loaded round in the longer 280 Ackley chamber the case stretch will be .014 to .018 plus your head space (Normally .001 to .0015).

So a person has to make up his mind if he wants a SAMMI chamber or a Ackley chamber. As I have said before there is a difference in the chamber lengths and he has to decide if he wants to use every brand of 280 rem brass With the Ackley, or use only the Nosler brass
in the SAMMI chamber. If you do decide to use the Nosler SAMMI AI chamber in order to use the standard 280 brass you should full size it and bump the shoulder back .014 thousandths before loading and firing it the first time to prevent case stretch.

This is a safety issue and for sure a component issue.

I have chambered several dozen of both chambers and made it clear to the owners of the difference and the risk if this rule is not followed, and have had none of the problems discussed.

J E CUSTOM

Wow lots of information to process here, and a bit confusing?? And please what I am writing here is not in arguing, I am trying to understand this whole concept. From what I have read you make really nice custom rifles, so I believe that you know what about what you are writing here. I went to the Nosler web site, and got some dimensions from there. They are showing the datum point of the .280 Rem, from the base of the cartridge to the shoulder/neck @ being 2.199 and the datum point for the .280 AI (SAAMI) @ 2.182 = .017 making the .280 AI (SAAMI) shorter by .017 thousandths than the .280 Rem.. Are the dimensions in Nosler's web site incorrect? What you have written is that the datum point for the .280 Rem @ 2.1924 and the datum point for the .280 AI (SAAMI) @ 2.172 = .0204 thousandths difference. I do not have the dimensions for the straight .280 Ackley Improved so cannot make any more determinations other than what is written. Is the .280 ACKLEY IMPROVED (original Ackley) reamer the same reamer that a smith would use to chamber the .280 AI (SAAMI) only the chamber is .014 thousandths deeper on the original Ackley Improved?

 

[Derek1280]

Your right JEcustom i missed that was a saami. Mine own rifle is the original Ackley version. My redding dies say 280rem improved 40degrees. All original ackleys pre 2011 wer supposedly marked thus way

 

[Derek1280]

Have ever heard or read this?

 

[J E Custom]

Wow lots of information to process here, and a bit confusing?? And please what I am writing here is not in arguing, I am trying to understand this whole concept. From what I have read you make really nice custom rifles, so I believe that you know what about what you are writing here. I went to the Nosler web site, and got some dimensions from there. They are showing the datum point of the .280 Rem, from the base of the cartridge to the shoulder/neck @ being 2.199 and the datum point for the .280 AI (SAAMI) @ 2.182 = .017 making the .280 AI (SAAMI) shorter by .017 thousandths than the .280 Rem.. Are the dimensions in Nosler's web site incorrect? What you have written is that the datum point for the .280 Rem @ 2.1924 and the datum point for the .280 AI (SAAMI) @ 2.172 = .0204 thousandths difference. I do not have the dimensions for the straight .280 Ackley Improved so cannot make any more determinations other than what is written. Is the .280 ACKLEY IMPROVED (original Ackley) reamer the same reamer that a smith would use to chamber the .280 AI (SAAMI) only the chamber is .014 thousandths deeper on the original Ackley Improved?

You are correct, and I don't take it anyway but that you are trying to understand what and why. The dimension on the 280 rem is the same from the case head to the body neck junction, As the 280 Ackley. The SAMMI drawing for the 280 Rem is based on the datum line and it is 2.1042 but the body neck dimension is/would be 2.1993 and stay the same in the Ackley after it is fire formed. The datum line would change when going to the 40o shoulder but the neck to case head would not.

Dave kiff with PT@G made the original dies for Nosler based on the Ackley dimensions but they changed them. He wrote an article about the problems they would have if they didn't correct this difference but they decided to go on with the difference. (I suspect it had to do with Ammo sales because you would have to use there ammo and/or their brass exclusively if you chambered with the new SAMMI spec.

It has caused many debates and will probably never be resolved. But when you compare the SAMMI specs like you did for the 280 Rem and the New SAMMI 280 AI you will see the difference and no matter what anyone says, .014 to .018 difference is to much to interchange
the two without problems.

This is not My theory or idea, it is a SAMMI fact and all the internet videos and post will not change the facts. I'm sure Nosler would like to say it's the same but they can't. And they wont admit that they made a mistake as Dave reminded them.

So we are on our own with this great cartridge and have to understand what the difference is and deal with it. I for one will never own a SAMMI (Nosler) 280 AI because I don't want to be held ransom when I go to buy brass or ammo. There is nothing wrong with ether one when loaded proper fitting ammo. and the added length (.014 to .018) Doesn't add enough powder capacity to make a measurable difference in velocity, so it just becomes a personal decision as to which one.

J E CUSTOM

 

[Derek1280]

So in your opinion original version is saft to fire form from factory loaded 280rem?

 

[Alibiiv]

You are correct, and I don't take it anyway but that you are trying to understand what and why. The dimension on the 280 rem is the same from the case head to the body neck junction, As the 280 Ackley. The SAMMI drawing for the 280 Rem is based on the datum line and it is 2.1042 but the body neck dimension is/would be 2.1993 and stay the same in the Ackley after it is fire formed. The datum line would change when going to the 40o shoulder but the neck to case head would not.

Dave kiff with PT@G made the original dies for Nosler based on the Ackley dimensions but they changed them. He wrote an article about the problems they would have if they didn't correct this difference but they decided to go on with the difference. (I suspect it had to do with Ammo sales because you would have to use there ammo and/or their brass exclusively if you chambered with the new SAMMI spec.

It has caused many debates and will probably never be resolved. But when you compare the SAMMI specs like you did for the 280 Rem and the New SAMMI 280 AI you will see the difference and no matter what anyone says, .014 to .018 difference is to much to interchange
the two without problems.

This is not My theory or idea, it is a SAMMI fact and all the internet videos and post will not change the facts. I'm sure Nosler would like to say it's the same but they can't. And they wont admit that they made a mistake as Dave reminded them.

So we are on our own with this great cartridge and have to understand what the difference is and deal with it. I for one will never own a SAMMI (Nosler) 280 AI because I don't want to be held ransom when I go to buy brass or ammo. There is nothing wrong with ether one when loaded proper fitting ammo. and the added length (.014 to .018) Doesn't add enough powder capacity to make a measurable difference in velocity, so it just becomes a personal decision as to which one.

J E CUSTOM

I totally agree with you about being held ransom by a company in reference to brass. I wrote this in a previous post here. I have a problem paying double or triple the cost of brass or bullet heads for that matter. It doesn't cost anymore to manufacture a .270 Winchester brass than it does to manufacture .280 AI brass, yet they're charging triple the cost for the.280AI than the.270 brass. I'm willing to spend money on tools that will allow me to make my own brass out of another caliber out of principle!! And I'm certainly not a rich guy, just have principles!!!

 

[Edd]

I believe most, and perhaps all, off the shelf 280 Rem ammo can be chambered and fired in a SAAMI 280AI chamber and an original 280AI chamber.

I think off the shelf SAAMI 280AI ammo should only be fired in a SAAMI chamber.

So if I was building one, I would want a SAAMI chamber.

 

[Alibiiv]

Wow there is so much controversy over the specs on this caliber, I am thinking another caliber instead!! WOW!!!! I tried a search in these forums. The results dating back to 2013 were very complicated and there were a number of people who were pretty much arguing about who was right and who was wrong. I typed in, "280 Ackley Improved SAAMI vs .280 Ackley Improved (40`) good luck with that!! I believe that Nosler had input into the controversy as JE Custom wrote in a previous posting here.

I have also been thinking about the .270 Ackley Improved (40`) original wildcat or the .270 Sherman or a .280 Sherman!! If one reads about the original .270 Ackley Improved (40`) the posts and literature reads that Ackley himself did not feel that the 40` improved version of the .270 really did nothing for the caliber because it was already overbore; however, that was 30+ years ago before the new powders that have hit the market. I cannot seem to find anything on the dimensions for the original .270AI. And....now the Sherman, for me, really is not going to happen because I was told that the magazine box on the Ruger, tang safety in .270 Winchester is too short for the cartridge/caliber; the box measures 3.350. I have a safe full of Ruger tang safety rifles and intend to use two of the Rugers in .270 Win as donor rifles for two builds that I intend to make; one for me and one for my son. I found a gunsmith in Montana who likes working on Rugers, who is good at working on them, and who has agreed to build the rifles for me. He's very reputable with a number of good recommendations and comments on his work! The rifles are ready to go, just need to settle on a freakin caliber!! I've been at this now for at least 6 months, first finding someone who was willing to work on a Ruger and who was good at it, and now a "caliber", it's getting frustrating at this point!

 

[Edd]

Don't let all the rambling keep you from getting what you want. It isn't very complicated. Just look at the numbers.

 

[Alibiiv]

Don't let all the rambling keep you from getting what you want. It isn't very complicated. Just look at the numbers.

Thank you Edd, maybe ought to take a break on all of this. As I started out with this thread, I have been reloading for many many years and never realized how technical all the long range shooting and reloading for it can be. I'll figure this out, just a matter of time. I like the versatility of the .280 AI, I am thinking that if I have to go through all the work to make the SAAMI Ackley Improved, maybe it's worth it to have a .280 AI (40`) original and go from there. As J E Custom addressed in a previous reply, I don't like be held ransom for brass. Thank you again and thank you to everyone who has been giving their input and replies on the thread.

 

[Edd]

Brass will cost you the same for either chamber. The only difference is you will have an additional option for the SAAMI chamber.

 

[Edd]

If you have a SAAMI chamber, you can form your brass from standard 280 brass or you can buy brass already formed.

If you have the original chamber, you will need to form your brass from standard 280 brass.

 

[TOM H]

Nosler 280AI case length is 2.525 and I don't have any Hornady but their data show case length for 280AI @ 2.525". The case length for 280 is 2.540" same as 270

There is only one Kenny Jarrett and he's built lot of 280AI also sold ammo.
http://www.jarrettrifles.com/pet-calibers.html

When Nolder published loading data for 280 Rem Ackely Improved in Manual # 4 and Kenny Jarrett did write up it and it was wildcat back then and length for that 280 Rem Ackley Improved was 2.525".

I shoot 35 WhelenAI and case length is same as 30-06 and my 243AI same length as 243,222AI same as 222. If you look Nosler manual 22-250AI is same length as 22-250,257 Roberts AI same length as 257. When Ackley did 30-06AI it was same length as 30-06.

Why would Ackley shorten that case

 

[Alibiiv]

Gotcha as JE Custom wrote in a reply yesterday @ 7:30PM, Nosler was warned that there would be a problem making the changes that they did, however manufactured their cartridge under Ackley's name anyways. You are now the second person who has replied with the same information. Perhaps Nosler ought to have called "their" cartridge ".280 Nosler" instead of using Ackley's name, but....then maybe it would not have been so appealing to the shooting community. And if they did use the name .280 Nosler that then would be getting confused with the 28 Nosler, the new addition to the Nosler line of cartridges. You're right about all of the original Ackley cartridges, he did nothing to change the overall length of the case, that was the beauty of all his improvements.