280AI trim length

m2m

Looks like you did everything just right and made all the right choices to fix each problem as it came along.

Yes if you have a SAAMI spec chamber and an older full length of body die, then the die would size the case body thus balooning the shoulder forward and causing a severe crush fit. Then the solution would be to take some off the shell holder or bottom of the die to make it reach the shoulder.

The sequence of events you outlined are logical and predictable with your chamber and die.

IMO
 
Ok gents, time to resurrect this one for some more discussion. I'm one of the thoroughly puzzled 280ai newbie owners. I bought a 280ai two years ago, used. The guy I bought it from provided the reamer specs and I believe this to be a Saami spec reamer. I've been loading with Nosler brass. I usually neck size but after my third loading, cases were tight in the chamber and the bolt was tight.

I set up a redding 280 imp 40* body die per the instructions (to the shell holder), lubed a case a ran it through. It was extremely tight on the case body. I pulled the case and tried it in the action- bolt didn't come close to closing!

I turned the die a quarter turn down and did it again, still would fit in the chamber! I inked the shoulder and neck with a sharpie and went back to the press. Turned the die another quarter turn down. This time the press was camming over hard. There was no mark on the blackened shoulder. Tried the brass in the chamber- no fit!

I sacrificed a shell holder and sanded a few thousands off it (about .008). This allowed me to still turn the die down and not cam so much. Relubed, resized again and got just the slightest ring in the sharpie mark on the brass at the just below the shoulder neck junction. Tried this in the chamber and it was extremely tight but the bolt closed. A little more sharpie removed from the brass after this.

Took a few more thousands off the shell holder, turned die another 1/8 turn down and repeated another run through the die. This time the die showed good contact with the sharpie coating the shoulder. Put the brass in the chamber and the bolt closed as if it were new brass!

Earlier in this post I read per Dave Manson "Finally, re-loading. Don't use dies made to the old spec to re-size cases fired in SAAMI-spec chambers. The few re-size dies I checked that were made to the "old" spec would not reach the shoulder of a case fired in the SAAMI chamber."

Is it possible I have redding dies made to old spec? I tried a redding type s full length sizer with the same results as the body die that came out of a competition set. Is there a way to know?

An additional note. In my .223AI, new parent case .223 Rem brass has a "crush fit" which I was told is by design to ensure a snug fit of the brass for fireforming. With my 280ai, no crush or snugness of factory new 280Rem brass.

Any ideas about what the heck I have going on? Thanks!! Whew!


Nosler and Sierra manual had the same case measurement for the 280AI and case length was 2.525" same as what SAAMI spec is

http://www.saami.org/PubResources/CC_Drawings/Rifle/280 Ackley Improved.pdf

Nosler changed their manual 2007 to conform to SAMMI spec for the 280AI which was approved 2008.

I'm sure sometime maybe 2006 they were working Nolser manual since it came out 2007 and those reamers for the 280AI SAAMI spec were in place. It was 2008 that you could buy Nolser 280AI brass and I got some back then.

My wifes 280AI was complete June 2006 and it chambers Nosler 280AI brass and my 280AI build couple years ago chamber 280AI brass fine and I use same Reddin280AI body die and Wislon neck and seater die.

.What you might do is call Redding tell them about reamer print you have they may be able to help you out.
 
My wifes 280AI was complete June 2006 and it chambers Nosler 280AI brass and my 280AI build couple years ago chamber 280AI brass fine

Either the older 280AI chamber or the new SAAMI spec 280AI chamber will accept the Nosler 280AI brass. That brass is smaller than necessary for the older chamber but it will still chamber and shoot in the older chambers. The problem is that in the older chamber the Nosler 280AI brass will have .014" to .017" headspace which will cause very flattened primers
 
Either the older 280AI chamber or the new SAAMI spec 280AI chamber will accept the Nosler 280AI brass. That brass is smaller than necessary for the older chamber but it will still chamber and shoot in the older chambers. The problem is that in the older chamber the Nosler 280AI brass will have .014" to .017" headspace which will cause very flattened primers


I do own other Ackleys but I do know from having them build I do ask lot of question as to headspace etc and I like to find out which dies will size what I'm having chambered. I've also have dies made after I get few cases did that for the 222AI and 223AI from Neil Jones.

Woods, I don't have what you have to confirm what your telling me so no need to get into a contest over that. Is your chamber like the ones in Sierra manual or Nosler before 2007 manual?
 
I have the older Ackley chamber done by Hart when they rebarreled. I discovered the problem after I used some Nosler 280AI brass. The primers looked like this

Picture017.jpg


wondering what was going on when IDbound clued me in with his post

http://www.longrangehunting.com/forums/f28/280ai-question-69160/index2.html

and directed me to GunSmith talk about it

280 Ackley Improved Alert | GunsmithTalk

Now I just use 280 rem caliber brass and I don't have a problem. I still used the Nosler 280AI brass after it was fireformed with no problem but flattened primers like that are not something to repeat.

So according to all information that I have seen, the Nosler 280AI brass is made smaller to fit the new SAAMI specs with appropriate headspace. But that also means that Nosler 280AI brass will fit in either the new or the old chambers.
 
I have the older Ackley chamber done by Hart when they rebarreled. I discovered the problem after I used some Nosler 280AI brass. The primers looked like this

Picture017.jpg


wondering what was going on when IDbound clued me in with his post

http://www.longrangehunting.com/forums/f28/280ai-question-69160/index2.html

and directed me to GunSmith talk about it

280 Ackley Improved Alert | GunsmithTalk

Now I just use 280 rem caliber brass and I don't have a problem. I still used the Nosler 280AI brass after it was fireformed with no problem but flattened primers like that are not something to repeat.

So according to all information that I have seen, the Nosler 280AI brass is made smaller to fit the new SAAMI specs with appropriate headspace. But that also means that Nosler 280AI brass will fit in either the new or the old chambers.

Nosler has loading data for other AI cases and they all match what in Sierra manual and since those manuals been out for a number of years that would be a good source for loading data. The 280AI in those manuals is bigger than the 280 case since the case was blown out and the Nosler 280AI brass is larger then those two case in earlier Nolser manual and 280AI in Sierra manual. Sierra/Nosler had case dia at the shoulder .450" and SAAMI spec is .454" and they lengthen the case body .007" and to the start of neck .005" so it has little more case capacity. they keep case length 2.525"

What Nosler did if you look at cases like 22-250,243,6rem,270,257,30-06 that have been used for the AI case dia at the shoulder has been .454/.455". Nolser change the dia from .450" to .454" to bring in more to the AI dia.

I'm sure die's were made to those two diagrams in earlier Nolser/Sierra manuals and I'm sure if they were different it would of been known.

there is also a 280 Improved which is listed in "THE HANDLOADER'S MANUAL OF CARTRIDGE CONVERSIONS" which is different also.

I'm looking at reloading manuasl that have those two prints of the 280AI and Nosler SAAMI Spec print and if your chamber was different you made of had something else.
 
280-ai-vs-280-ai-saami.jpg


I have the older true 280AI chamber and when I use Nosler 280AI brass I have .014"+ headspace

Don't know how to make it any plainer than that
 
Metal2meat, redding makes two different full length dies one says 280 improved 40 degree which is for the older chambering and i believe the newer one says. 280 ackley.
 
You need to know what your chamber length is .

SAAMI spec is 2.525 for the AI and 2.540 for the 280 rem.

Nosler is the only one loading the 280 AI and recently standardized it by submitting it to
SAAMI (It had not been one of the SAAMI cartriges before).

It almost looks like they wanted to corner the ammo market for the AI version because they
changed the dimensions slightly over the standard AI reamers of the past. they were designed
to fire form using the standard 280 Rem cases.

Older AI reamers are made long enough to fire form 280 ammo in them. This is the reason
you need to find out what is the case length in your chamber.

If a fired 280 case will fit in your chamber with out effort it is probably OK, if not you chamber
is to short to use without trimming.

Ultimately what you want is a case neck that is .010 to .020 shorter than your chamber.

J E CUSTOM
What I don't get is the 280 Rem minimum chamber length is 2.56. The 280 Ackley minimum chamber length is 2.56. So why would the case length spec on the 280 Rem be 2.54 and the Ackley be 2.525? Regardless of the angle of the shoulder and length of the neck wouldn't you be more consistent in establishing what length short of the chamber would be your target?

Is a gun is chambered SAAMI 2.56 I would think your trim length would be around 2.54 as well? Or am I reading these wrong? I understand the difference in shoulder location from the old AI to the new specs... but as far as target trim length it seems they would be similar. It seems the SAAMI case length is too short.

http://www.saami.org/pubresources/cc_drawings/Rifle/280%20Remington%20-%207mm%20Express.pdf

http://www.saami.org/pubresources/cc_drawings/Rifle/280 Ackley Improved.pdf
 
Last edited:
I have the same question as boog.

What is my max case length in the saami .280 ackley?

I can't read a reamer print very well...
 
Warning! This thread is more than 10 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.
Top