280 AI concerns

[azgutpile]

I just had the head space of my buddies 280 AI checked out by a local gunsmith and he informed me that it was loose, but not excessive. When he used a standard 280 remington No-Go guage the bolt would close, but it took a little extra effort.

What is the normal/ original process of checking the headspace in a 280 AI? I thought you were supposed to use the go guage as the no go guage on the 280 AI.

FYI, the reason we had the headspace rechecked was because of a case seperation during our last deer hunt, the other was is when we fire form the cases in this rifle, we have to seat the bullets into the lands; otherwise, we get some case distortion just above the case head.

The rifle is a Remington 700 action with a Krieger barrel.



Please let me know your thoughts.

 

[shortgrass]

Is the chamber the "traditional" Ackley or the Nosler Ackley?

 

[azgutpile]

It was supposed to be the original 280AI.

 

[shortgrass]

Traditional .280 Ackley uses the GO, for the .280 Remington, as the NO-GO. Chambering reamers for the .280 Ackley, those that have been made since Nosler standardized it, are of the SAAMI/Nosler dimentions. Gauges are different for the Nosler. I've not tried .280 Rem. gauges in a Nosler chamber. Take the rifle back to whoever cut the chamber for an answer. NO effort should ever be used to close the bolt on any head space gauge.

 

[pmh-usa]

And thank the fine folks at Nosler for this mess . . . you watch, the next long accepted wildcat they 'standardize' will be the same way

 

[dsink]

Was his chamber a rechamber on a factory barrel? If so, was the barrel set back a thread?

 

[J E Custom]

There have been lot's of discussions on the difference in head space between the two different 280 AIs and if you do a search you will find lot's of information.

J E CUSTOM

 

[azgutpile]

I had the rifle checked by two separate gunsmiths, one was able to close the bolt on the 280 Rem (Standard) no-go gauge and he estimated it had an excess headspace of .008" and the other was able to close the bolt on a 280 Rem go gauge with a piece of tape on the back and felt it was within spec.

The other issue that we have is that he purchased the new 280AI SAAMI/ dies, which if you follow the directions in the box will set the shoulder back an additional .014". This left us with a headspace of .017"- .022"

Since the owner of the gun is new to reloading and has the new SAAMI dies already, we are setting the barrel back 1 turn and having it rechambered to the new 280AI SAAMI/ Nosler design. This hopefully will eliminate all of the issues. We will be using new a brand new reamer and gauges.

Thanks for all the help.

 

[shortgrass]

Follwing your above stated plan, which makes good sense by the way, you will either be limited to using Nosler brass or "jamming the bullet" if you use .280 Rem. brass. Unfortunately, there are many other rifles with "issues" findiing their way into the market. Anyone who owns a lathe and has cut a chamber or two for themselves is now a "gunsmith".

 

[FEENIX]

Anyone who owns a lathe and has cut a chamber or two for themselves is now a "gunsmith".

LL!

 

[J E Custom]

I had the rifle checked by two separate gunsmiths, one was able to close the bolt on the 280 Rem (Standard) no-go gauge and he estimated it had an excess headspace of .008" and the other was able to close the bolt on a 280 Rem go gauge with a piece of tape on the back and felt it was within spec.

The other issue that we have is that he purchased the new 280AI SAAMI/ dies, which if you follow the directions in the box will set the shoulder back an additional .014". This left us with a headspace of .017"- .022"

Since the owner of the gun is new to reloading and has the new SAAMI dies already, we are setting the barrel back 1 turn and having it rechambered to the new 280AI SAAMI/ Nosler design. This hopefully will eliminate all of the issues. We will be using new a brand new reamer and gauges.

Thanks for all the help.

First; Two different gunsmiths should not have gotten two different head space clearances.
The chamber did not change from one to the other.

The "New" 280 AI should be .012 to .014 Thousandths shorter than the original 280 AI, which should not allow a standard 280 rem head space gauge to close in the "New" 280 AI.

Tape on the back of a head space gauge is not a good way to measure head space (It can be compressed and give false readings) brass or stainless shim stock is the only way to accurately
measure head space.

SO- If you can close the bolt on a 280 Remington head space gauge (Do not force it) you have the original 280 AI chamber and can shoot all 280 ammo EXCEPT the new Nosler ammo.

If You have the "New" chamber, you should not be able to close the bolt using the 280 Head space gauge(The standard 280 head space gauge is used to set head space for the OLD 280 AI so standard 280 ammo can be fired safely while fire forming to the AI chamber).

You can jam the 280 or 280 AI into the "NEW" AI chamber most of the time but sizing the brass
to fit the new chamber is recommended.

If you have the "NEW" AI chamber you should only shoot Nosler Ammo in it.

If you have the old AI chamber you can shoot all ammo except the Nosler safely.(Shooting the Nosler ammo in a Original AI Chamber can lead to case splitting because of excessive head space.
So you must know what chamber you have.

The "NEW" AI dies can be used in ether chamber if set correctly after fire forming.

Hope this helps, And as Shortgrass said: Just because a person has barreled a couple of actions this
does not automatically make them a gun smith.

Proper head space is paramount for safety and accuracy, so it should be measured correctly and precisely.

J E CUSTOM

 

[atrietch]

I will say this first, I am not a reloader as of now. I have a lot to learn. I am a hunter first and foremost.
I bought a new Kimber 84L Montana in .280 AI. I had it sent directly to a gunsmith to do some "weight reduction work" and I am now getting a game plan to break in the barrel correctly.
My head is spinning regarding now.

1. Is my Kimber the new "Nosler" headspace?
2. If it is, I assume I am all set to shoot the nosler factory ammo?
3. But can I shoot standard .280rem during break in to save $?
4. And if it is ok to shoot the .280rem in my Kimber, will the cases be fireformed correctly for when I do start to reload?

I hope I am not asking questions that seem redundantly simple to you guys. I have tried to search function and I just get more confused to all the diff data.
Thanks in advance for any help.

 

[shortgrass]

I will say this first, I am not a reloader as of now. I have a lot to learn. I am a hunter first and foremost.
I bought a new Kimber 84L Montana in .280 AI. I had it sent directly to a gunsmith to do some "weight reduction work" and I am now getting a game plan to break in the barrel correctly.
My head is spinning regarding now.

1. Is my Kimber the new "Nosler" headspace?
2. If it is, I assume I am all set to shoot the nosler factory ammo?
3. But can I shoot standard .280rem during break in to save $?
4. And if it is ok to shoot the .280rem in my Kimber, will the cases be fireformed correctly for when I do start to reload?

I hope I am not asking questions that seem redundantly simple to you guys. I have tried to search function and I just get more confused to all the diff data.
Thanks in advance for any help.

The new Nosler .280 A.I. is the SAAMI specification. If your rifle is new, it should be to SAAMI specs. If it is, you should shoot Nosler factory .280 A.I. ammo. You should not shoot factory loaded .280 Rem. ammo in the Nosler chamber. The instructions that came with the rifle or Kimber, themselves, can tell you if the chamber is to the new Nosler specs or if it's the "traditional" version, like P.O. Ackley designed.

 

[atrietch]

Thanks, the Kimber is at the Gunsmith's now. I will check the paper work.
So happy I just picked up a couple boxes of .280 rem yesterday...