280 A.I. and Nosler Ammo

[hglass]

I just had Mickey Coleman make me a 280 A.I. rifle. In anticipation of receiving my barreled action I purchased two boxes of Nosler 280 A.I. brass and one box of finished ammo (140 gr. AccuBond).
To my surprise the brass nor the ammo when chambered does not allow me to close the bolt. I sent the barrelled action back to Mickey and he said it is dead on to SAAMI specs. Which says Nosler brass and finished ammo are not to SAAMI specs. Anyone else experieance this problem?

 

[SJB358]

Welcome to the forum buddy. As to your 280 Improved issues. I haven't the slightest clue really. There are enough of the 280AI shooters here to help you out though.

Does the ammo allow bolt closure at all? Or is it a tight crush fit? Just wondering, seems like this would have surfaced more with all the recent 280 AI guys. Scotty

 

[hglass]

The bolt does not close at all.

 

[SJB358]

I would give Nosler a call this morning when they open. Might be worth going over what the specs are and what your rifle is chambered to. I really don't have much to assist with the problem, but if your rifle is on the tight side of SAAMI it could be the issue? Again, I am just talking out of my butt as I am not any kind of expert in chambering cartridges. Scotty

 

[DrMike]

It is possible that your gunsmith cut the chamber with an RCBS angle (30 degrees) rather than cutting it for the Ackley angle (40 degrees). The more likely issue is that you now have a gun cut for the Ackley version rather than for the SAAMI/Nosler chamber. When Nosler standardised the cartridge, they found that the Remington Custom Shop had shortened the headspace by 0.014 inches. Nosler kept these numbers, changing the original design from what P.O. Ackley had submitted. Remington believed the change was necessary for fireforming 280 Remington ammunition in an Ackley chamber. The bottom line is that you cannot safely use Nosler brass in a traditional Ackley chamber, although it is still safe to fire form factory ammo in a SAAMI/Nosler chamber. Many gunsmiths seem to be confused on this issue. In your case, you likely now have a true Ackley chamber.

 

[NoslerMP]

I had a nice conversation with Mr. Glass yesterday morning, and we are working on finding the source of his problem. It sounds as though his chamber is cut to a different spec.

 

[nvbroncrider]

If a standard .280 will chamber that will verify? Then shoot and you will know the answer by comparing.

 

[elkeater2]

Wonder if this ever got resolved? It seems like if OP had a true Ackley 40 degree chamber, the Nosler ammo and brass would be undersize and fall in with no bolt stoppage. If I read it right, the spec called for .014" shorter headspace. As always, there are definition and semantics issues to deal with, but the accepted measurement for '06 type rimless cases is the distance from the bolt face to the "datum line" on the shoulder.

I'm curious, because I am about to have my 7mm/06 reamed out to some kind of 280 AI. I was on one of the reamer rental sites, and they specifically noted this issue (Nosler/SAAMI vs. original Ackley) and have reamers for each. I will probably go with the Nosler version, since having brass and ammo available without having to fireform is handy.

So, DrMike, hglass, NoslerMP......which case has more headspace, and is my take on all this flawed?
Elkeater2

 

[JD338]

My 280 AI was cut to the datum line on the shoulder of a R-P case. There is a slight crush fit when chambering a virgin case 280 Remington.
The Nosler 280 AI brass is 50/50 to fit my tight chamber, even if I full length resize it. The measurements I have taken on the Nosler 280 AI brass fall within their spec. I have a very tight chamber at accepts R-P brass without a hitch so I have to do the fire form step.

JD338

 

[elkeater2]

JD338,
I added a case diagram pic to my recent post..Curious how I find the Nosler spec you mentioned.? Oh, I found another case diagram with 2.101" to the shoulder base, so now I'm seeing three different possibilities. Hmmm.
EE2

 

[elkeater2]

As usual, I'm a little behind on this topic. There was a thread earlier this year that covered it pretty well...
viewtopic.php?f=4&t=15233&start=15&hilit=ackley+specifications

Sorry, it still doesn't explain why the OP's new barrel won't swallow the Nosler brass or ammo.
EE2