.280 ACKLEY IMPROVED

Kotimaki

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Jan 13, 2019
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I picked up a kimber hunter 84l in 280 ackley this summer and am finally getting around to load development. I decided to start with the Berger classic 168 and 4831. Saami spec on the 280ai is 3.330 coal. This rifle jams a bullet into the lands at a coal of3.250 tight enough that it will pull bullets every time. So I'm looking at loading to 3.240 to start for a 10 thou jump. This throws published load data and pressures out the window. Anybody have a formula to estimate pressure increase vs diminished case capacity?
 

Don Fischer

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Jun 27, 2017
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Just start low with published data and work up. You will be fine
For crying out loud, lot's of people say that. I have a better idea. Start low with published data and work up. Ah shoot, that's what you said! Your a pretty smart feller! Make the OLL what ever your rifle can handle.
 

VikingsGuy

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I picked up a kimber hunter 84l in 280 ackley this summer and am finally getting around to load development. I decided to start with the Berger classic 168 and 4831. Saami spec on the 280ai is 3.330 coal. This rifle jams a bullet into the lands at a coal of3.250 tight enough that it will pull bullets every time. So I'm looking at loading to 3.240 to start for a 10 thou jump. This throws published load data and pressures out the window. Anybody have a formula to estimate pressure increase vs diminished case capacity?
Brockel called it. But if you are curious for more info you can post on the handloadersbench.com forum and typically somebody will run the numbers through QuickLoad for you.
 
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Kotimaki

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Jan 13, 2019
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Worked my way up to 60.5 ...no pressure signs. Low node was too low , high node seems about exactly what I was looking for. 60.5 is just over 3000 and 3/4 group. This rifle does heat up fast and consistently throws the 3rd shot to the right an inch or more. Ten minutes between rounds made a huge difference. All in all I think I'm going to like this rifle.
 

std7mag

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Aug 23, 2016
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central pa
Ummm, you don't specify WHICH 4831...
There is a difference!
Just like 4350.

And you don't have to go to handloaders for some Quickload data. Just PM me with your specs.
Already got bullet, COAL.
Just need barrel length, and which powder.
 

Millsworks

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Feb 6, 2017
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Quick load takes all the adventure and education out of the loading process.
You will never actually know till you run em down the barrel.
I recommend 20 thousands jump as the most, 15 is usually great for accuracy and reliable loading in and out of the chamber.
Load a few and give it a tweak hear and there and run some more.
Start 6-8 grains below Max and go with the 10 thou jump. You can increase powder or seat the bullet deeper on several as you go, checking for pressure sighns, accuracy, and speed if you have a chrony.
 

std7mag

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8gr lower seems a big step. To me at least.
Depending upon powder, there is the possibility of getting pressure spikes due to not enough case fill.

As with everything, Quickload is a tool. Use with caution.
 

VikingsGuy

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Aug 2, 2017
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8gr lower seems a big step. To me at least.
Depending upon powder, there is the possibility of getting pressure spikes due to not enough case fill.

As with everything, Quickload is a tool. Use with caution.
10% below max is general loadbook advice. I tend to start 5-7% below and have never had pressure signs in the first two-thirds of a ladder. YMMV.
 
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