Fireforming Brass for a 280 AI

[biggelaar22]

Not sure if this has been posted before or not, but I am curious if I should run standard 280 Rem brass through an AI FL Die prior to forming it in the rifle to ensure a proper seal or if I should just load it as is and shoot it to form it to the chamber? (Yes, 280 AI brass is really expensive and hard to get, especially if it is not Nosler)

Just wondering cause I have a tight chamber 280 AI rifle that I would like some cheaper brass for to build an alternate load for plinking/target.

Any good information in this field would be greatly appreciated.

Thanks

[rugerfan]

I’ve always used factory brass in my 280ai, but I’ve had a couple other ai chamberings as well and always just used standard dies for the first loading when fireforming.

[fps plus]

Yes one can fire standard 280 rem in your 280 ackley. That’s the nice thing about ackley chambers. Just load a standard charge for a 280 rem and fire it . Surprisingly accuracy and velocity can be very good doing so . Some like to wipe the cartridge to be fired and formed with a lite coat of oil feeling it helps them form better

[catnthehat]

Although I do not have a 280AI, I have owned four different AI chambered rifles and never had an issue with shooting srandard ammo in them to make the brass.
The last was a 6mmRemAI. And it was very accurate with standard 6mm Remington ammo

Cat

[Pathfinder76]

Why would you run it through the AI die first? The only possible differing outcome is that you create excessive headspace. Don’t do it.

[Dean2]

The Ackley chamber is slightly wider in the body , with a sharper shoulder. Factory 280 brass actually has more head space than AI brass does but running factory brass through an AI sizing die will do nothing. The die can make AI brass back into regular brass by squeezing it down, it can't expand regular brass to AI dimensions, the only way to do that is to fire form it. As the others have said,Fire form your brass, as all AI rounds were designed to do exactly that, and then you are good to go from there.

[biggelaar22]

Thanks guys. I appreciate the info.

The only reason I would run it through the die was mostly due to having a shorter headspace than spec on the rifle, that was the thought until I was educated by guys more knowledgeable than me. ( Plus from my understanding, headspace is basically how the casing seals to the chamber, which also fed a bit of confusion cause standard 280 has a longer headspace than the ai).

Tight groups fellas.

[Dean2]

In the 280, head space is set off of where the shoulder contacts the chamber. The same is true on the AI. The much sharper angle of the AI's 40 degree shoulder is what sets the head space in the AI. The standard 280 will fit in the AI chamber with no issues at all.

[fps plus]

There is some confusion as to the headspacing . The standard 280 headspaces of a point on the shoulder . The Ackleys headspace off the junction of the neck and the shoulder . This is why one can fire a standard cartridge in an ackley chamber .

[Dean2]

Originally Posted by fps plus

There is some confusion as to the headspacing . The standard 280 headspaces of a point on the shoulder . The Ackleys headspace off the junction of the neck and the shoulder . This is why one can fire a standard cartridge in an ackley chamber .

Much clearer description than the one I provided. Datum line versus neck/shoulder junction.