.280 AI controversy explained ...

[varmintH8R]

I have read a ton of posts on this site and others, gunsmith bulletins, etc. I have not found anything that definitively answers the question in my mind. When it comes to reloading, I do not tolerate any uncertainty. Since I don't know for sure, I will continue to fireform.

I certainly agree with the comments that all pre-SAAMI reamers are not all the same. That said, the practical side is that the PO Ackley design used a "negative" or crush headspace to allow for fireforming sharp shoulders. If there were a significant amount of "rogue" chambers reamed so that new SAAMI brass is 14 thou short, it seems to me there would have been a lot of legacy issues in fireforming from 280rem brass.

I think the situation in general is both "bull chips" and "horse hockey" as it has not been definitively answered by a major company with skin in the game (at least that I have seen). Nosler??????

 

[woods]

woods
Cockcroft
Tnwhip

3 and counting in just our little sample

 

[FEENIX]

Just curious what kind of pressure you guys generated with the load that caused it to flatten the primers.

Almost 3 years ago I loaded for a friend, he had a Ruger M77 MKII in .280 Rem that was accurized and AI'd by Brad Stair of Wasatch Precision Arms (WPA) in UT. The hottest load was 60gr of H4831SC, 140gr NAB, BR2, using Nosler .280 AI virgin brass, and .005" off the lands. No pressure signs, no flatten primers.

 

[Tnwhip]

Just curious what kind of pressure you guys generated with the load that caused it to flatten the primers.

Almost 3 years ago I loaded for a friend, he had a Ruger M77 MKII in .280 Rem that was accurized and AI'd by Brad Stair of Wasatch Precision Arms (WPA) in UT. The hottest load was 60gr of H4831SC, 140gr NAB, BR2, using Nosler .280 AI virgin brass, and .005" off the lands. No pressure signs, no flatten primers.

I looked at my records and I started out with 56g of 4831 and a 139 g SST, Nosler brass and a Win. large rifle primer. That is 2 g. under max in my old hornandy book for a regular 280 rem. My primers were so flat it scared me. I went home and checked my load to make sure I didn't screw up. I checked my fired brass against my unfired brass and they were .014 short. I called my gundsmith that chambered it. He could not under stand what was wrong,That is when I got on the internet and found out what Nosler had done. I then necked up my brass to 30 cal and necked back down to 7mm leaving a shoulder to fit tight in the chamber and fireformed all my brass. Everything is find now. My load I am shooting is 63.5g H-1000 with a 162 A-max no problem.

 

[woods]

Just curious what kind of pressure you guys generated with the load that caused it to flatten the primers.

Pressure is very seldom the cause of flattened primers. When the case is fired it moves forward in the chamber until it is stopped (distance determined by headspace), the primer backs out and to the bolt face, the case expands backwards to the bolt face. The primer is being squeezed between the bolt face and the pressure from the expanding gas of powder burning coming through the primer hole.

The edges of the primer that are not supported within the primer pocket by the case head will be flattened.

My flattened primers were not because of pressure. It was a known load that was not causing problems with loose primer pockets, shiny spots on case head or hard bolt lift. Velocity was as expected.

 

[FEENIX]

I posted the same video on another gun site/forum and no one seems to have any problems. However, this response stands out the most from a member that I have the utmost respect for his expert opinion, vast experience, and candor but most especially his willingness to share them to help others ... and I am not alone that look up to him.

Originally posted by XXXXXXX
[br]FEENIX,

...any word of wisdom on the video claim?

One word?

No, but I can conjure up about 3-4,000 in one sitting just to try to clear up the BS that Redding and SAAMI have given us. The problem is that this amount of writing, to do correctly, could take me a couple of hours which I simply don't have these days. Sorry.

In short though, I measure everything before I start a chamber, this includes the reamer, headspace gauge and brass. Why? Too many stupid people in the manufacturing end of this business who don't want to afford Quality Control. Example:

I just sent 4 brand new reamers ($700.00) back to the maker because they were absolutely wrong according to my prints. They pulled the wrong prints from file instead of using the ones I specified in writing. Then to compound the error, they intentionally neglected to measure the reamers and check the prints I asked for.

I've been cutting chambers for Ackley cartridges for a long time. I've never had a failure of any type occur from any of the 200+ Ackley chambers. I follow Ackley's guidelines and I measure everything, twice if necessary. I also test fire every one at least once then measure the case again.

There never was a controversy and there never will be when the rules are followed by people that have been trained properly.

Best.

I x-out his screen name just in case, he didn't care to be quoted outside the forum.

 

[woods]

FEENIX I'm happy for you that you got the direction you seem to need.

But what exactly did he say? He clearly said he had not paid any attention to the video yet and blamed Redding and SAAMI for a big screwup. Then he talked generically about doing a good job. That is good advice.

So an untested blanket statement that absolutely positively without a doubt there is no controversy, unless someone screwed up.

What did we learn. An un-named authority (according to you) doesn't examine the evidence, rants about work ethic and settles the matter offhand without explanation (much like the video!)

BULLCHIPS

 

[Tnwhip]

One thing about it. My fault, your fault, my gunsmiths fault, nobody's fault. My rifle is not a SAMMI chamber. it is .014 longer, just like a lot of 280 Ack. rifles out there. I except that fact. I will fireform all my cases out of 280 or 270 brass just like they have been doing for 50 years. If others rifles can use the Nosler 280 Ack.IMP. brass that is fine with me. My case holds a little more powder, Na Na Na. LOL

 

[FEENIX]

FEENIX I'm happy for you that you got the direction you seem to need.

But what exactly did he say? He clearly said he had not paid any attention to the video yet and blamed Redding and SAAMI for a big screwup. Then he talked generically about doing a good job. That is good advice.

So an untested blanket statement that absolutely positively without a doubt there is no controversy, unless someone screwed up.

What did we learn. An un-named authority (according to you) doesn't examine the evidence, rants about work ethic and settles the matter offhand without explanation (much like the video!)

BULLCHIPS

So are you saying you're the authority on this subject?

 

[FEENIX]

One thing about it. My fault, your fault, my gunsmiths fault, nobody's fault. My rifle is not a SAMMI chamber. it is .014 longer, just like a lot of 280 Ack. rifles out there. I except that fact. I will fireform all my cases out of 280 or 270 brass just like they have been doing for 50 years. If others rifles can use the Nosler 280 Ack.IMP. brass that is fine with me. My case holds a little more powder, Na Na Na. LOL

You sir is a better man for accepting the fact and more importantly recognizing the fault.

I originally considered .280 AI but went for .270 AI instead and couldn't be happier.

 

[bigngreen]

One reamer, two gauges and two chambers that end in the same head space, not hard math lightbulb

 

[woods]

So are you saying you're the authority on this subject?

Typical straw man argument

"type of argument and is an informal fallacy based on misrepresentation of an opponent's position.[3] To "attack a straw man" is to create the illusion of having refuted a proposition by replacing it with a superficially similar yet unequivalent proposition (the "straw man"), and to refute it, without ever having actually refuted the original position"

A video was posted that stated the "controversy was solved" and I replied simply but graphically. When pushed I linked 3 different sources of information outlining the different headspace for old and new (which the video did not address)

2 other posters explained their similar experience to mine outlining the headspace difference

Then an expert opinion was posted that said basically nothing

So if you can point me at data or facts that prove that the .014" difference does not exist, then please do. I don't know if you have any personal experience with this since you have not posted it and I am not trying to make it personal.

Perhaps the problem is that some are labeling it a "controversy". In my mind it is controversial in that Nosler and Remington have decided that they were the authority on 280AI without concern for many many years of history on chambering for the caliber. Also controversial would be the fact that Nosler sold their 280AI brass without an advisory or warning on the box that some chambers might have excess headspace.

So is that solved?

 

[woods]

I originally considered .280 AI but went for .270 AI instead and couldn't be happier.

Perhaps when Remington and Nosler come along and set a SAAMI standard that has a headspace that is .014" shorter than your chamber and brass starts being manufactured for it at the new SAAMI standard

Then you will know how we feel

PS don't know if 270AI is already SAAMI standardized but you should get my point

 

[J E Custom]

Now I am confused.

I have built many 280 AIs and decided when this question came to light I looked at the SAMME
dimensions and found the same dimension difference.

I am a head space fanatic and like .0000 to .0005 for accuracy and could not feel comfortable with
having a chamber that could (In My Opinion) only shoot one brand of ammo when simply using the
280 Remington Go Gage I could use all of the other brands.

I under stand that if you chamber and head space with the new SAMME 280 AI it should be safe
to shoot other brands of ammo, But the head space is still an issue If you shoot anything but the
Nosler ammo in my mind.

So by using the SAMME 280 AI reamer and the 280 Remington go gauge you eliminate any possibility
of to much head space as long as you don't shoot the Nosler ammo.

So in my mind, the choice is that you can shoot one brand of ammo, or all other brands to fire form.

After that the reloader has control of the head space.

I,M not sure if it is OK to shoot the shorter ammo or not, I,m just not willing to find out.

A .014 thousandths short chamber is not a problem for most bolts to close on with cases that head space
on the shoulder, But in my mind a .014 thousandth long chamber Is a questionable
condition.

Controversy or not, As a smith I have to feel that I have built a safe rifle or I just wont do it.

While fire forming, In my experience I have found that less head space is better because it prevents
the case from moving forward while fire forming thinning the web of the brass (A common cause of
case head separation).

I can appreciate all of the different opinions and like to see and hear them because that's what this
web site is known for.

Everyone has a good argument and I have had my mind changed before but not yet on this subject.

J E CUSTOM