280AI question

[David Emerson]

I didn't read every post in the thread so apologies if I am rehashing ...

By definition an "AI" chamber can safely shoot the original/parent case. This means you should be able to safely chamber and fire a 280 Rem in a 280 Rem AI chamber ... and they are almost always amazingly accurate even with shooting the non AI parent in the AI rifle. Therefore - a 280 Rem Go guage will not suffice as a no-go guage for either a 280 Rem or 280 Rem AI.

I have a 260 AI ... I used the 308 go and no go guages for headspacing - it works perfect. I'd check with a smith to be sure but you should be able to use 280 Rem/270win/30-06/25-06/etc go and no go guages to headspace your 280 AI. If not then I suggest to be safest, get your hands on 280 Rem AI go/no go guages.

BTW - I have many times for my own personal use/rifles, used a go guage as a no go guage by adding 5-6 thou of additional length ... electrical tape can work very well for this for a very limited # of bolt closes (2-4). Take this for what it is worth and at your own risk - be cautious ...

 

[David Emerson]

The problem lies in the gentle shoulder of the parent case. So you need to set resistance against the blow of the firing pin.

 

[nkyshooter]

The problem lies in the gentle shoulder of the parent case. So you need to set resistance against the blow of the firing pin.

... true ... for best results when fire forming ... this is typically achieved by loading long to a bit of a jam to create that extra confidence that the case will not move forward upon being stricken by the firing pin. However, the neck shoulder junction creates the resistance needed to fire - even without a 'jam' - and even conservative length factory 280 Rem will fire reliably and safely in the 280 Rem AI without any attention to anything else ... it is a great way in fact to get an initial set of AI cases if you don't have any AI brass to start with.

 

[David Emerson]

... true ... for best results when fire forming ... this is typically achieved by loading long to a bit of a jam to create that extra confidence that the case will not move forward upon being stricken by the firing pin. However, the neck shoulder junction creates the resistance needed to fire - even without a 'jam' - and even conservative length factory 280 Rem will fire reliably and safely in the 280 Rem AI without any attention to anything else ... it is a great way in fact to get an initial set of AI cases if you don't have any AI brass to start with.

I am glad you read a lot

 

[nkyshooter]

Hey David - no disrespect intended to you ... I've been shooting ackley's in various calibers since I was 8 ... well over 40 years ... wish there was more to read about them actually.

To OP ... you have to use the parent cartridge NO go guage as the NO go for the AI chamber ...

 

[David Emerson]

A no go is longer than a go. That is exactly opposite of what you need when making an ackley. There needs to be a crush fit when changing to an ackley to keep from stretching the case at the web or head.

 

[antelopedundee]

I didn't read every post in the thread so apologies if I am rehashing ...

By definition an "AI" chamber can safely shoot the original/parent case. This means you should be able to safely chamber and fire a 280 Rem in a 280 Rem AI chamber ... and they are almost always amazingly accurate even with shooting the non AI parent in the AI rifle. Therefore - a 280 Rem Go guage will not suffice as a no-go guage for either a 280 Rem or 280 Rem AI.

I have a 260 AI ... I used the 308 go and no go guages for headspacing - it works perfect. I'd check with a smith to be sure but you should be able to use 280 Rem/270win/30-06/25-06/etc go and no go guages to headspace your 280 AI. If not then I suggest to be safest, get your hands on 280 Rem AI go/no go guages.

BTW - I have many times for my own personal use/rifles, used a go guage as a no go guage by adding 5-6 thou of additional length ... electrical tape can work very well for this for a very limited # of bolt closes (2-4). Take this for what it is worth and at your own risk - be cautious ...

The .280 Rem is about .050 longer to the shoulder than the .270, .30-06 or .25-06 cases.

 

[shortgrass]

The .280 Rem is about .050 longer to the shoulder than the .270, .30-06 or .25-06 cases.

So , .30/06 gauges WILL NOT WORK CORRECTLY IN THE .280 Rem or .280 AI.

 

[shortgrass]

https://mansonreamers.files.wordpress.com/2015/06/ackley_gaging1.pdf

 

[shortgrass]

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[CjC73]

all this is making me think I should have went my original direction of making this a 280 Sherman. And I just might still. I have 338 Sherman dies I can use with a different neck bushing and 100pcs of new Peterson 280 Rem brass waiting to be fire formed.

I'm going to use the AI go-gage with tape on the bottom for a no-go and go from there.

 

[SavageHunter11]

So I have a remage 280AI barrel I installed using a 280AI go gage and a 280 Rem go gage as the no-go gage.

I screwed the barrel on till it hit the go gage and tightened the nut. I then put the 'no-go' gage in and it still closes, but with some slight resistance and the bolt wouldn't pull the gage out either.

Is this normal? Is this what allows me to shoot 280 Rem brass to fireform?

Just want to make sure I did this right.

As a guy who built a 280A.I. with a Remage setup like you please make sure you know what Go and No-go gauges you have because there are two different versions of it. There is the original that Ackley himself made and then there is the SAAMI spec version that Nosler made and they are both different. I had a good spat with my gunsmith trying to explain to him that he set my barrel to Ackley specs when I specifically requested SAAMI spec and him telling me thatI have no idea what I'm talking about and that he's the professional

 

[shortgrass]

Setting up an Ackley isn't hard, you just don' know what you're doing and trying to learn on the internet!

 

[antelopedundee]

... true ... for best results when fire forming ... this is typically achieved by loading long to a bit of a jam to create that extra confidence that the case will not move forward upon being stricken by the firing pin. However, the neck shoulder junction creates the resistance needed to fire - even without a 'jam' - and even conservative length factory 280 Rem will fire reliably and safely in the 280 Rem AI without any attention to anything else ... it is a great way in fact to get an initial set of AI cases if you don't have any AI brass to start with.

Starting with .280AI brass avoids the problem of shortened cases that you get when you fire form standard .280 cases. IIRC this shortens them by about .015 or so and may contribute to the formation of carbon rings or so some say.