280 Ackley Chamber

fraz01

Well-Known Member
Joined
Dec 9, 2020
Messages
190
Location
washington
Forgot to mention that I have a buddy who is using Peterson brass in his Saami chambered 280AI. He is very impressed with the brass. Was using Nosler with good results but is pushing the Peterson a little harder and has had good brass life so far. Peterson has some loaded ammo, don't know if they load any 280 AI. 280 is definitely an over achiever.
 

Justice1327

Well-Known Member
Joined
Jan 29, 2021
Messages
647
Location
USA
I know that this has been hashed and re-hashed.
I've searched everywhere and conversations seem to end in a giant axle-wrap.
Some say that you can fire a factory Nosler 280AI or Federal AI round in a SAAMI chamber.
Nosler has been quoted as saying not to fire Nosler ammo in the "old Ackley" chamber.
Maybe that's a CYA statement ?

Here's my dilemma :

1) I would like my rifle to be able to safely shoot Nosler and Federal ammo.
2) My smith only has the old Ackley reamer.
3) Can the old reamer be used for this ?
4) How much "jump" is max for the factory ammo ?

What if I used this information to set my throat ?
My mag box is 3.7" and I would like to shoot 168gr Bergers when I can find them.
Before Nosler had the SAAMI specs done on the 280AI, the ‘old’ 280AI was 14th longer in headspace. Today’s 280R ammo can be fired in a 280 AI. But not the other way around
 
Last edited:

Mcranch

Well-Known Member
Joined
Jan 7, 2021
Messages
91
Location
Texas
I have the old 40* 280 AI chambered in 94. So I can’t buy Nosler 280 AI shells and load them up and fire away? I fire form 280 rem nickel plate shells and after fire form. 160 AB RL19 I moved over two clicks and fire two more after the first three I’m older now and after more than two cups of Java I’m not as steady l used to put em in right close This is a Krieger #3 at 25”on a sako av I picked up for 60 bucks these were shot last November .?McMillan stock back then when you could get one for 235 I think I got about 980 in it with a Leupold 50 when they first came out when I rebarrel I would guess it would be the saami New style chamber I guess I would have to get ahold of John and have a chat with him back then they would do the threads and have you ready to head space twist up and bed your stock I think I want to look into a 30 nosler with a custom 700? Maybe even consider a prefit action?
2DA70767-F395-4D7E-A039-7D38554E7E4B.jpeg
 

KoolBreeze

Well-Known Member
Joined
Mar 6, 2016
Messages
65
Wow, such a confusing topic with so much back and forth it's hard for a layman such as myself to know what works and what don't. But I gather factory loaded 280 Remington ammo can be "safely" fired in the SAMMI 280AI rifle?
 

KoolBreeze

Well-Known Member
Joined
Mar 6, 2016
Messages
65
When I bought my 280 AI, one of the reasons I did was because I had a good bit 280 Rem ammo on hand and ammo these days is, well, you know. Still haven't shot the rifle but plan to hopefully this weekend. It has a SAMMI compliant 280 Ackley Improved chamber. I have a couple boxes of different off-the-shelf 280 AI ammo for it, so hopefully it will like that. However, if it doesn't can I safely fire 280 Rem ammo in it or not? I'm reading in some threads you can but in others you can't due to the shorter chamber.
 

Bob Wright

Well-Known Member
Joined
Jan 23, 2018
Messages
1,834
Location
Litchfield Park, Az.
When I bought my 280 AI, one of the reasons I did was because I had a good bit 280 Rem ammo on hand and ammo these days is, well, you know. Still haven't shot the rifle but plan to hopefully this weekend. It has a SAMMI compliant 280 Ackley Improved chamber. I have a couple boxes of different off-the-shelf 280 AI ammo for it, so hopefully it will like that. However, if it doesn't can I safely fire 280 Rem ammo in it or not? I'm reading in some threads you can but in others you can't due to the shorter chamber.
Is your 280AI a factory rifle as opposed to one that a Smith built? The reason I ask is if they used a "match reamer" on a custom build, you should have the chamber cast performed and find out if the neck of the chamber is on the low side of tolerance. I have been having to turn necks on any brass I use due to match chambers.
It's easily remedied if so.
 

KoolBreeze

Well-Known Member
Joined
Mar 6, 2016
Messages
65
Is your 280AI a factory rifle as opposed to one that a Smith built? The reason I ask is if they used a "match reamer" on a custom build, you should have the chamber cast performed and find out if the neck of the chamber is on the low side of tolerance. I have been having to turn necks on any brass I use due to match chambers.
It's easily remedied if so.

Yes, it's a factory Browning xbolt.
 

Clark

Well-Known Member
Joined
Oct 19, 2006
Messages
762
I have the SAAMI reamer, the SAAMI headspace gauge, and Nosler 280AI brass.

My trouble was with the neck diameter of the Lee and Redding sizer dies, but I just use new Nosler brass.


We generally like the neck to be honed to 0.002" smaller than the loaded ammo, to allow for the elastic deformation of brass [spring back]. when Forster does it. But they don't make a 280AI die.

0.3105 - 0.002" = 0.3085"

1) Redding with a neck that is a go with a 0.303" pin gauge
2) Lee Precision with a neck that is a go with a 0.298" pin gauge
 

Attachments

  • 280 Ackley Imrpoved neck diameter 0.3105 in loaded 20180515_220630 (1).jpg
    280 Ackley Imrpoved neck diameter 0.3105 in loaded 20180515_220630 (1).jpg
    137.4 KB · Views: 15

Darryle

Well-Known Member
LRH Team Member
Joined
Apr 19, 2019
Messages
453
Location
Weatherford, Texas
I have the SAAMI reamer, the SAAMI headspace gauge, and Nosler 280AI brass.

My trouble was with the neck diameter of the Lee and Redding sizer dies, but I just use new Nosler brass.


We generally like the neck to be honed to 0.002" smaller than the loaded ammo, to allow for the elastic deformation of brass [spring back]. when Forster does it. But they don't make a 280AI die.

0.3105 - 0.002" = 0.3085"

1) Redding with a neck that is a go with a 0.303" pin gauge
2) Lee Precision with a neck that is a go with a 0.298" pin gauge
.002" smaller or larger in OD?

Wouldn't .002" smaller be an interference fit?
 

shortgrass

Well-Known Member
Joined
Mar 31, 2010
Messages
3,318
Location
Weatherford, Oklahoma
.002" smaller would raise pressures dramatically. That condition would do nothing to enhance accuracy, and it could be down right dangerous! In a 'hunting rifle' .004-.006 would be about right with .004 being on the tight side.
 

KRP

Well-Known Member
Joined
Dec 25, 2007
Messages
608
Location
Kuna, ID
.002" smaller or larger in OD?

Wouldn't .002" smaller be an interference fit?
.002" smaller would raise pressures dramatically. That condition would do nothing to enhance accuracy, and it could be down right dangerous! In a 'hunting rifle' .004-.006 would be about right with .004 being on the tight side.
He's talking about sizing dies not the chamber.
 
Top