Home Forums Reloading Big Game Rifles 280 ai SAMMI die set

Howdy all, I have a new 280 ai SAMMI spec rifle being built and want to order a die system for it.

I was wondering if the Lee collet die marked 280 Remington / 7mm Express will work with the new 280 ai.

To bump the shoulder I was wondering if the Redding body die has been updated to be used with the new sammi specs. It is marked 280 Remington Ackley Improved 40 degree shoulder.

For seaters I have read that in-line type bullet seaters are the way to go and wanting to avoid the expensive redding competition seater how about the
Hornady Custom Grade New Dimension 2-Die Set 280 Remington Ackley Improved 40-Degree Shoulder?

If anyone has used these with the new 280 ai I'd like your opinions or any other system that has worked for you.

Many thanks!

I have an older 280AI chamber but do use the dies you mentioned. I would think the Lee Collet would size all the neck to very close to the neck/shoulder junction. Close enought so that it would not make any difference.

The reason I say this is because I had Lee make me a Lee Collet for my 6.5 rem mag and it does not quite reach the neck/shoulder junction. I think it even helps! That gun shoots light out

Now I am not sure about the Redding Body Die. The SAAMI chamber has a shoulder that is supposed to be approx .014" closer to the case head so the Body Die may not reach down low enough to size the shoulder. Worst case scenarion is that you may have to take it to a machine shop and have them take off an 1/8" or so. It will be case hardened material so a file probably won't work.

I would go for it anyway because the benefits of the Lee Collet & Redding Body Die are worth it.

Any Redding dies made after 2011, are to saami spec, and are stamped .280 Ackley Improved. Those made before 2011, are to the older wilcat spec., and are stamped .280 Rem. Improved 40*. If the die you are looking at is Redding and is stamped .280 Remington Impoved 40* ,they are not the saami spec dies.

Takeing an eighth of an inch off would be way to much! 1/8th of an inch is .125" way more than .014"

You can adjust the die by setting it and locking it down. A die does not have to hit the shell holder to size

True, but why cut an eighth of an inch off, when there is only .014" differance.

Looking at the Midway website literally everything they have for Redding listed is marked 280 Remington Ackley Improved 40 degree shoulder. Am I to believe all of those dies listed are made before 2011 or are they just mislabeled?

Lets try this, you guys are alot smarter than me so only thing I have is the 280 Remington / 7mm express Lee collet die in hand to size necks.

I need to seat and bump the shoulder.

What would you get/do for my to be SAMMI chamber?

thanks!

Because you may not be able to reach the shoulder to push it back. I had to do this on a 22-250 body die, couldn't reach the shoulder and press was maxed out. Had a machine shop take a little off the bottom of the die and good to go

Get the Redding Body Die. It may reach and push the shoulder back, if it doesn't then take a little off the bottom of the die or the top of the shell holder.

No other die will size the case body and push the shoulder back without messing up the neck sizing you are doing with the Lee Collet. IOW you will have to go to an expander ball type with all the jerking that critter up through the neck and the lube inside the neck. Perhaps they make a bushing type that will push the shoulder back also but they are expensive and IMO don't produce as good a neck as a Lee Collet.

I have the Reddiding die set, stamped .280 Ackley improved. It is to saami spec. Midway did have them.Redding also sells shellholders in .001' increments so you can adjust your shoulder bump. I am a tool and die maker, and have an optical comparator at work I have checked both cases, and indeed there is only .014" between them. Type in .280 Ackley Improved in the search box on the Redding site.

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280 Ackley Improved vs. 280 Rem. Improved 40 Degree
The SAAMI spec cartridge carries the approved name of " 280 Ackley Improved " .
The older wildcat has several names including 280 Ackley Improved 40�, 280 Rem Improved 40�, 280 Imp 40�, 280 Ackley, 280 Rem Imp, and more.
The SAAMI spec 280 Ackley Improved chamber is .014 inches shorter at the datum line headspace dimension than the traditionally accepted wildcat chamber spec as previously produced.
Our current production dies are for chambers that are cut to the SAAMI specification and are stamped "280 Ackley Imp".
Any Redding dies made before 2011 are stamped " 280 Rem Imp 40� " and are built to the originally accepted wildcat specs.
These older dies will not bump the shoulder of cases for a SAAMI chamber. In other words, the old dies are too deep for the current SAAMI chamber.
Redding makes a Competition shellholder that is .014 deeper than the standard #1 shellholder so the owner of a wildcat chamber can use the current SAAMI spec dies for safe resizing.

Failing to use this shellholder or to back the die away from a standard shellholder by a minimum of 0.014" will result in too much shoulder bump which may create an unsafe, excessive headspace condition when fired in a traditionally dimensioned wildcat chamber.

To find the die part numbers for a current production SAAMI spec. rifle, please download our current catalog as a .pdf from www.redding-reloading.com.
You will find these dies listed in Series C and Category II. Limited quantities of the traditional wildcat dies which are marked " 280 Rem Imp 40� " are available at Custom Series Die prices.

Bottom line, don't rely on only the web.
The names many list for this cartridge can be misleading.
Remember, they are wildcat cartridges and adhere to no formal standard.

Note: Any dies that Redding makes for SAAMI approved cartridges are always stamped with the SAAMI approved name or abbreviation.



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Good information Bogtrotter

So now if you have an older Ackley you can find one of the old dies marked 280 Rem Imp 40* or get the thicker shellholder and use with dies marked 280 Ackley Improved

If you have the SAAMI chamber you get one of the new dies marked 280 Ackley Improved or take some off the bottom of the die or shellholder

I get that right?

Yup, You could always use .014-.015 feeler stock to set the die. (saami die)w/ older wildcat chamber and standard shell holder.

You can rely on Bogtrotter to get it straight for you. He has been a tool and die maker for years and has gotten me out of my reloading screw ups many times over. Even built gun parts that were not readily available. Good guy to know. Good shooting.

How about Redding stamped "280 ackley Imp" ? Not improved spelled out.

Personally I think you should do yourself a favor and buy a new set of either RCBS or Redding 280AckImp dies and you'll be good to go. Either will get you on your way to sizing the brass to your SAMMI chamber. You talking about using this die to size the body, that one for the neck and on and on. Ultimately it's up to you, but it seems like your plan has alot of moving parts. That's why I suggested buying 1 die set to do it all..

In 2019, I bought a Kimber Hunter in 280AckImp and I got a set of Redding dies that included the F/L, neck, and seater dies. I have no issues and have sized brass made by Hornady, Peterson, Federal and R-P fireformed 280rem brass without fail or losing any cases.

Good luck with your new rifle and I look forward to seeing some range reports.

This is what I recently bought for my Ruger #1. For the money (free shipping) it's a no brainer.

https://www.midwayusa.com/product/101244296?pid=196260