.280 Ackley Improved load data

[Snowfighter]

Long Range Hunters.
Working on some hand loads for my .280 AI.
Getting moderate results. I was wondering if improper head spacing would cause premature signs of high pressure. Using factory Nosler .280 AI brass and noticed they vary more than I like. Cracked open a new box of brass and loaded some tests. Got signs of high pressure with moderate loads.
Anybody got ideas?
Thanks

 

[wapiti25]

Using a blade micrometer measure the case just ahead of the extractor groove but behind the pressure bulge. Measure before firing new brass and mark with a Sharpie so you can measure the same spot later after firing. Measure and record the reading to a tenth of a thousandth ( .xxx1 ). After firing when you get expansion there the case has reached it's limit. Std mic is too wide to fit and caliper won't read accurate enough. When you see expansion ( .0001 or more) back off one grain or more to keep from ruining the brass .

 

[wapiti25]

Check the chamber with a 280 REM go-gage. The go-gage should be tight when you try to close the bolt or may not close on the go-gage. The Ackley chamber needs to be slightly shorter than the 280 Rem chamber for proper head space.

 

[Snowfighter]

Got it. Thanks for the info. I will work on that.

 

[Snowfighter]

So Ive got another question now. Want go give the Burger 168gr hunting VLD and Hornady 162gr A-Max a go. Having a hard time locating load data for these specific rounds. Was thinking about starting with the .280 Rem data about a grain down from max. Anybody know where to get more accurate load data for these in the .280 AI?

 

[shortgrass]

Now that Nosler has standardized the .280 Improved, we have two of them. The .280 Nosler Improved and the Traditional .280 Ackley Improved. Headspacing is not the same. The Nosler chamber is shorter. For the traditional, as previously mentioned, the "GO" gauge becomes the "NO-GO" gauge. If you have a "Traditional" chamber and wish to use Nosler .280 Improved brass, cartridges need to be loaded with the bullet slightly jammed into the rifling. This method makes sure that the base of the cartrige will be against the bolt face and stretching will take place at the shoulder end of the case not the head end. Stretching at the head end will give signals of high pressure, because the case is thinning there not at the shoulder end, as it should. Loading .280 Remington cases, and firing in a "Traditional" chamber has the case firmly supported between the bolt face and the neck/shoulder junction and "improving" (brass stretching) will take place at the shoulder end, leaving the head end as it should be. If you put a .280 Rem. cartridge in a .280 Nosler Improved to fire form it, you probably won't be able to get the bolt fully closed.

 

[bheadboy]

having had 2 280AI, if found the following to work for me,
take the std water volume for the 280 case, and the water volume for the 280 AI case fired in your chamber,
Calculate the % incresase in volume.
then take the max loads for the std 280 and increase them gradually to the % increase of water volume.

you will hit a point of velocity/lpressure that is ok and the accurcy what you want.

it is a great round.

Bob