.280AI SAAMI vs. Original Chambering

Troutslayer2

Well-Known Member
Joined
May 28, 2010
Messages
756
I've got a .280AI that I bought used several years ago. It shoots awesome with loads using virgin Nosler 280AI brass. Because of all of the confusion regarding headspace on the old vs. SAAMI chambring, I have been a little reluctant to reload the once fired brass that is piling up. What do I do? How do I know if the brass is safe to reload or if it's been too stretched by 1x firing because it's Nosler SAAMI spec brass and I believe my gun predates Nosler changing the case dimensions and "standardizing" it.

In my head, the brass if now fireformed to my chamber, but from what I read, the webbing may be stretched. I know this topic has been beaten to death because I feel like I've read every article on the internet about it. I still don't really know how to determine if the brass is safe to reload or if I have to fireform 280 Remington brass in order to be able to reload it. Am I overthinking this? I don't have a headspace gauge, is that something I should get? What other measuring devices should I own to help me get through this?
 
I've got a .280AI that I bought used several years ago. It shoots awesome with loads using virgin Nosler 280AI brass. Because of all of the confusion regarding headspace on the old vs. SAAMI chambring, I have been a little reluctant to reload the once fired brass that is piling up. What do I do? How do I know if the brass is safe to reload or if it's been too stretched by 1x firing because it's Nosler SAAMI spec brass and I believe my gun predates Nosler changing the case dimensions and "standardizing" it.

In my head, the brass if now fireformed to my chamber, but from what I read, the webbing may be stretched. I know this topic has been beaten to death because I feel like I've read every article on the internet about it. I still don't really know how to determine if the brass is safe to reload or if I have to fireform 280 Remington brass in order to be able to reload it. Am I overthinking this? I don't have a headspace gauge, is that something I should get? What other measuring devices should I own to help me get through this?


Lots of people have used the new Nosler brass in their older chambers with little or no problems.

Head space is still a problem in some chambers and case head separation is still a possibility depending on the older AI chamber.

I feel it is best to use the Nosler brass In the new SAMMI chamber and all other brands of 280 brass
in the older chamber just to be safe.

As you said, there have been lots of debates about this and many opinions so you are on your own
because your chamber could be close enough to the new chamber that you don't have a problem, or it could be just the opposite, and your cases could/will fail early.

Most people think that it is just easier to buy the Nosler brass/ammo and shoot it because it is already to the new SAMMI size and it will save fire forming. But a properly head spaced AI chamber
is unbelievably accurate when firing 280 Remington cases/ammo and there is no chance of case head separation.

This problem has nothing to do with cost, it is about head space and the effects of it when it exceeds
.003 or .004 thousandths. There are many different original AI chambers because of the reamers used and the head space that was used in them. (It can be as much as .014 to .018) more than the SAMMI chamber.

I would load the once fired brass and as you shoot it watch for signs of pending case head separation and toss all of it, or start over with quality 280 brass and don't worry about it.


J E CUSTOM
 
If I took my rifle to a good gunsmith, could they measure the headspace and give me a drawing of the chamber? That's what I feel like I need. I don't put a lot of rounds through this gun because I don't want to burn the barrel out. It's my go to lightweight hunting rifle. I have 100 pieces Nosler brass once fired in it, and I need to reload them ASAP.

And thanks JE for your insight. I appreciate it. I wish I had read all of this stuff before I went down the road of buying Nosler brass. At the time, I don't think anyone was talking about the difference. Kind of stupid on Nosler's part for not realizing this could be a big problem for people down the road.
 
I put a spent brass in a vice and cut it in half with a hacksaw. I'm feeling better about reloading this brass, but still interested in your opinions.
 

Attachments

  • IMG_0687.jpg
    IMG_0687.jpg
    210.4 KB · Views: 267
Buy a measuring tool and measure the fired cases and compare the measurement to some unfired cases.
 
Your sectioned case shows no sign of appreciable thinning above the base, so you are good to reload the case. Be sure you do not bump the shoulder back more than 0.002 she's you size the case. You need the tools to measure bump.
You can check for thinning with a paper clip bent 90 degrees at the tip. Slide it down the inside wall to feel for a thin spot above the base.
 
Great group! with a rifle that shot like that, I'd keep buying/shooting the same brass, forget about future handloads, ha. I've had wildcat rifles that shot well after their first fireforming. When I discovered this, set up at least 50 loads the exact way, after their first fireforming. That's what I hunt with. I don't care if I lose the brass when I pop a game animal and throw another in either! Brass is the cheapest thing about our hobby anyhow, ha. Nice, nice combo you got there...
 
If I took my rifle to a good gunsmith, could they measure the headspace and give me a drawing of the chamber? That's what I feel like I need. I don't put a lot of rounds through this gun because I don't want to burn the barrel out. It's my go to lightweight hunting rifle. I have 100 pieces Nosler brass once fired in it, and I need to reload them ASAP.

And thanks JE for your insight. I appreciate it. I wish I had read all of this stuff before I went down the road of buying Nosler brass. At the time, I don't think anyone was talking about the difference. Kind of stupid on Nosler's part for not realizing this could be a big problem for people down the road.

I have 2-280AI and this is about best information.

280 Ackley Improved vs. 280 Rem. Improved 40 Degree - Redding Reloading Equipment: reloading equipment for rifles, handguns, pistols, revolvers and SAECO bullet casting equipment
 


+1
This is what I have been saying to the membership since this problem showed up and was the same information the man that built the dies and reamers (Tooling)for Nosler said the problem was with the "New" 280 SAMMI chamber.

The smith that chambers it can alter it some, but not enough to correct/make up for the difference this this makes. (Especially If he places the correct head space on ether).

J E CUSTOM
 
have a custom set of dies made up- get LE WILSON straight dies made up- all my custom 25-06AI,- 7mm Rem mag AI - etc that Parker Ackley made up for me also cut the dies at the same time back when days..
 
Top