280 AI go

[Luke45]

Just ordered a 280 AI 26"mag contour from Mcgowan, **** i'm beyond addicted to savages now i want them all.
Do you use a standard 280 rem go gauge or do i need an ackley one? and if so i know there are a few differnt 280 ai variants. The one i got from McGowan was "280 ackley improved"

[KRP]

The headspace on a true Ackley chamber is shorter than the parent cartridge. Parent cartridge GO becomes the NO-GO in the Ackley chamber.

[Luke45]

The headspace on a true Ackley chamber is shorter than the parent cartridge. Parent cartridge GO becomes the NO-GO in the Ackley chamber.

so what would you suggest for barrel instilation? this is my first ackley

[Hotolds442]

Either order a headspace gauge in 280AI, find a gunsmith who has one, or have a machine shop remove .004" from a 280 Remington go gauge. If you have to buy the standard go gauge, you might as well just buy the AI version.

[Luke45]

Either order a headspace gauge in 280AI, find a gunsmith who has one, or have a machine shop remove .004" from a 280 Remington go gauge. If you have to buy the standard go gauge, you might as well just buy the AI version.

is there a difference int he chamber dimentions between the old ackly and the new sammi spec one? or is it just how far it is headspaced?

[Hotolds442]

http://gunsmithtalk.wordpress.com/2012/07/17/280-ackley-improved-emperical-headspace-test/

that should answer the question you're asking.

[Luke45]

http://gunsmithtalk.wordpress.com/2012/07/17/280-ackley-improved-emperical-headspace-test/

that should answer the question you're asking.

"The Chamber gauges pictured below were both made with the exact same 280 AI reamer. The only difference between the SAAMI and the Traditional chambers are the headspace gauges, all other measurements are identical."

Got this out of the article, thanks a million. im planning on doing my own fireforming, so the traditional headspace should be perfect. im still not quite sure why they changed the sammi one...

[Hotolds442]

I thought it was done to make sure the AI could not chamber in the 7mm Express.

[Luke45]

I thought it was done to make sure the AI could not chamber in the 7mm Express.

cool that makes sense, but then there basically isnt any reason to get the sammi gauges if your fireforming your own 280 brass then correct?

[Hotolds442]

You should at least get an AI go gauge or have a machinist remove .004 from a 280 go gauge. check to be sure that you're not too long on your setting which could cause dangerous case head separation due to excessive case stretching. Just tightening the barrel down on your brass and calling it good won't work because you need .004 crush on 280 brass to fireform it to AI dimensions.

[Luke45]

You should at least get an AI go gauge or have a machinist remove .004 from a 280 go gauge. check to be sure that you're not too long on your setting which could cause dangerous case head separation due to excessive case stretching. Just tightening the barrel down on your brass and calling it good won't work because you need .004 crush on 280 brass to fireform it to AI dimensions.

I meant the difference between getting the sammi 280 ai sized gauges vs the standard 280 AI gauges. what do you think? is there a benefit to either?

[Hotolds442]

If what the article says is true, then I wouldn't see a difference in the two.

[BillPa]

I meant the difference between getting the sammi 280 ai sized gauges vs the standard 280 AI gauges. what do you think? is there a benefit to either?

According to some the two are the same while others say they're not. I don't know, my 280 Imps were/are the traditional "Ackleys" save the RCBS (improved 30) I used to shoot.

Here's Redding's take.....
http://www.redding-reloading.com/tech-line-a-tips-faqs/133-280-changes%29:

You could email Dave Kiff (PTG) to get his opinion on the subject.

Bill

[FW Conch]

A "True Ackley" chamber is normally thought of as one which can fire the 280Rem or the 280RemAI in the same chamber. If I were going to use 280RemAI Factory Ammo, then I would set the Head Space to that ammo. But then the question would be, what Dies would I use if I wanted to reload? But I don't use Factory Loads, I reload and Fire Form to the chamber. When reloading, with what ever means is used to set headspace, I can load a round, touching the lands, and Fire Form to the chamber. This "may" produce a "slight" wildcat but I can proceed from there "as long as I have dies that are comparable with the chamber I have fire formed to. I may or may not then be able to use factory loads? From the information listed above, It sounds like the tolerances are close enough to not make to much difference, for lack of a better way to put it? I think in this case a "Chamber Cast" would be a good thing, especially to determine if the Dies used would be compatable.

Luke45- Not trying to complicate or over think this ;-))... Please keep us informed of your progress!...... Jim

[RiverSink]

I would get a set of standard 280 Go/NoGo gauges, fire standard 280 ammo to fireform and proceed from there. The same way it's been getting done for year's. Good luck.

[Luke45]

A "True Ackley" chamber is normally thought of as one which can fire the 280Rem or the 280RemAI in the same chamber. If I were going to use 280RemAI Factory Ammo, then I would set the Head Space to that ammo. But then the question would be, what Dies would I use if I wanted to reload? But I don't use Factory Loads, I reload and Fire Form to the chamber. When reloading, with what ever means is used to set headspace, I can load a round, touching the lands, and Fire Form to the chamber. This "may" produce a "slight" wildcat but I can proceed from there "as long as I have dies that are comparable with the chamber I have fire formed to. I may or may not then be able to use factory loads? From the information listed above, It sounds like the tolerances are close enough to not make to much difference, for lack of a better way to put it? I think in this case a "Chamber Cast" would be a good thing, especially to determine if the Dies used would be compatable.

Luke45- Not trying to complicate or over think this ;-))... Please keep us informed of your progress!...... Jim

Thanks for the advice guys ! i'm pretty sure i have the gist of it now.. Anybody have any good 280ai loads worked up with retumbo or H1000 or any other temp stable powders? I probablby will be shooting a 160 or 168 gr bergers or accubonds