Which is the better Ackley

[chad]

Which 280 Ackley is better? noslers 40' shoulder or the 30' shoulder?

 

[MudRunner2005]

Ackley also had a 40*, the 30* was another one of his various designs. Looking at a lot of the Ackley Improved case designs, it is obvious that he favored the 40 on most of his improved cartridges.

That being said, I prefer the 40. And all 3 of my Ackleys I specifically requested my smith use his 40-degree reamers (as he has both).

Since Nosler is also making .280 AI pre-formed new brass these days, I would go with the Nosler/SAAMI 40* version.

 

[Jokostel]

Horse a piece... the Nosler (saami spec) chamber is 40 deg.
It's been standard since 2008 if I recall correctly.

 

[TOM H]

Ackley did 3, 40',30'and 28'. The 28' was on 25,270 Ackley mag off the 300 H&H case.

Ackley did 244 with 30' and Fred Huntington (RCBS) did 243 Rockchucker with 32' shoulders.

Prior to the SAAMI Spec 280AI, Sierra and Nolser both had loading data for the 280 Ackley Improved and that had 40' shoulders.

Might want to read this

280 Ackley Improved vs. 280 Rem. Improved 40 Degree - Redding Reloading Equipment: reloading equipment for rifles, handguns, pistols, revolvers and SAECO bullet casting equipment

 

[PGJPJ]

i don't know that either is more efficient. practically speaking the SAAMI version would be easier since you can buy commercial brass.

 

[J E Custom]

i don't know that either is more efficient. practically speaking the SAAMI version would be easier since you can buy commercial brass.

This has been a long time debate and I don't want to start it over again but I prefer the "Old"
version of the 280 AI because you can use the more common 280 Rem Brass made buy many different ammo/brass makers.

When chambering this way, we reduce the head space .003 to .004 less than the 280 and fire forming is straight forward.

If you go with the "new" Nosler, the chamber is .014 shorter than the 280 rem (.018 - .004
= .014) and you should shoot only the Nosler brass or there ammo in that chamber at a much higher price.

http://www.saami.org/PubResources/CC_Drawings/Rifle/280 Remington - 7mm Express.pdf

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

If you look at the SAMME chamber drawings (The bottom drawing)you can see the difference in the 280 Rem case head to shoulder neck junction is 2.192 and the Nosler version Is 2.1742 (.018 shorter. Shooting factory 280 rem ammo in this chamber is almost impossible without heavy bolt
closing so you would be confined to using the Nosler brass and ammo.

Note: the same reamer is/can be used, it is just a matter of head space difference.

There is no power/velocity difference, just ammo and brass availability.

As far as the advantage of a 40o over a 30o shoulder, PO Ackley tested from 25o to 50o shoulders and came to the conclusion that 40o shoulders seemed
to be the most efficient and brass life was optimum. Less shoulder angle is thought to feed better by some but I have never had a problem with 40o shoulders feeding and brass life is definitely better.

J E CUSTOM

 

[Jerry M]

Thank you JE for explaining the difference is a simple manner.

 

[FEENIX]

Thank you JE for explaining the difference is a simple manner.

lightbulbHe always does and I enjoy reading his posts/responses and values his comments/recommendations.lightbulb

 

[TOM H]

This is interesting article from someone that worked for Ackley.

Handloader article on Ackley Imps.

 

[rharfo]

this has been a long time debate and i don't want to start it over again but i prefer the "old"
version of the 280 ai because you can use the more common 280 rem brass made buy many different ammo/brass makers.

When chambering this way, we reduce the head space .003 to .004 less than the 280 and fire forming is straight forward.

If you go with the "new" nosler, the chamber is .014 shorter than the 280 rem (.018 - .004
= .014) and you should shoot only the nosler brass or there ammo in that chamber at a much higher price.

http://www.saami.org/pubresources/cc_drawings/rifle/280 remington - 7mm express.pdf

http://www.saami.org/pubresources/cc_drawings/rifle/280 ackley improved.pdf

if you look at the samme chamber drawings (the bottom drawing)you can see the difference in the 280 rem case head to shoulder neck junction is 2.192 and the nosler version is 2.1742 (.018 shorter. Shooting factory 280 rem ammo in this chamber is almost impossible without heavy bolt
closing so you would be confined to using the nosler brass and ammo.

Note: The same reamer is/can be used, it is just a matter of head space difference.

There is no power/velocity difference, just ammo and brass availability.

As far as the advantage of a 40o over a 30o shoulder, po ackley tested from 25o to 50o shoulders and came to the conclusion that 40o shoulders seemed
to be the most efficient and brass life was optimum. Less shoulder angle is thought to feed better by some but i have never had a problem with 40o shoulders feeding and brass life is definitely better.

J e custom

+1

 

[Edd]

If I was going to build one, I would build the new Nosler version.

That way I could buy the already formed brass and ammo.

If I wanted to load some ammo with standard 280 brass, I could run that brass thru my AI dies and set the length to whatever it needed to be.

As for shooting off the shelf 280 ammo, I'm not sure that will be a consistent issue. It would depend on the exact measurements of the ammo and the chamber. As an example, with a 17.5° shoulder angle, if you had .006" cartridge/chamber neck clearance that clearance would consume about .010" of that extra length.

 

[Jokostel]

I've got about 250 some odd brass that I'll be converting to the Nosler/SAAMI spec....

Makes it easy peasy for bore sighting/barrel break in and plinking....
Just have to make sure that IF you choose to fireform 280s, use the 280 data to do such... otherwise you'll run into a few issues....
gun)

 

[J E Custom]

As for shooting off the shelf 280 ammo, I'm not sure that will be a consistent issue. It would depend on the exact measurements of the ammo and the chamber. As an example, with a 17.5° shoulder angle, if you had .006" cartridge/chamber neck clearance that clearance would consume about .010" of that extra length.[/QUOTE]




I have found that If the head space is set correctly - .003 to.004 less than the 280 head space gauge
all factory 280 rem ammo seams to work well and accuracy is very good and in some cases excellent.

This gives you the advantage of hunting accuracy using standard 280 rem ammo and fire forming cases at the same time saving even more money and having perfect fire formed brass that fits your chamber. (Even though you buy factory Nosler brass, it does not fit your chamber until it is fired the first time.

Again, why limit your self to "ONE" kind of brass when you can use all other brands and in a pinch if you go somewhere and forget or misplace your ammo, you can buy 280 rem ammo (Very common)and the hunt is not ruined).

In my way of thinking, this gives the older 280 AI an edge and is the reason I still like that version
because I don't like to limit myself to one case or one bullet In my rifles.

It doesn't matter which AI Version you decide to build they all perform great.

Just an opinion (Everyone has one)

J E CUSTOM

 

[TOM H]

Prior to the SAAMI Spec 280AI, Nosler and Sierra had loading data for the 280 Ackley Improved and that case just little different than SAAMI Spec 280AI.

If you look at Ackley data in his books for the 7mm/06 improved (Ackley) or 280 Rem Improved your not going to see much if any improvement over SAAMI spec 280AI or the old data from Sierra or Nosler.

Sierra and Nosler had reason for that data otherwise why would they included.

Don't get me wrong but I like the AI, beside 280AI on Rem action I have 222AI,243AI and 35 WhelenAI.