Shoulder bump on 280 Ackley problem....

KyleC

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Is it not possible to shoulder bump Ackley cases? I have no problem getting a .003-.004 shoulder bump on any of my other cartridges I load for but for some reason I do the same procedure and the bolt is really tight closing on a sized round.
 
There is a 280 Ackley wildcat, the original PO Ackley cartridge. And there's the more recent SAAMI approved "Ackley Improved". The original PO Ackley wildcat has a case head to shoulder datum 0.014" longer than the SAAMI "Ackley Improved" cartridge.

Redding made resizing dies for both cartridges. If you're using the original PO Ackley resizing die, you'll not be able to set the shoulder back on the SAAMI chambered cases. Because the PO Ackley resizing, or body, die will be 0.014" longer from base/bottom of die to shoulder datum.

If your Redding body die is stamped with "Ackley Improved" you should be good, provided your rifle is chambered properly for the SAAMI "Ackley Improved" cartridge. If not, you might have an older PO Ackley Redding body die.

Just one possibility...
 
I had a Redding 300wsm die i had to take some off the shell holder to bump the shoulder back, could be die is a little out of spec or headspace is a little tight.
 
Is it not possible to shoulder bump Ackley cases? I have no problem getting a .003-.004 shoulder bump on any of my other cartridges I load for but for some reason I do the same procedure and the bolt is really tight closing on a sized round.
Shave your shell holder down until you can resize. I just did this with my 223 AI
 
Is it not possible to shoulder bump Ackley cases? I have no problem getting a .003-.004 shoulder bump on any of my other cartridges I load for but for some reason I do the same procedure and the bolt is really tight closing on a sized round.
Here's the thing, the 40° shoulder is very good at resisting the bump and, when you do bump, the shoulder springs back MORE. The same thing happens with Weatherby shoulders, maybe .001" more of sizing is necessary as measured to get the desired results.
I had head scratching with 2 of my rounds at first, the 257AI and 375 Weatherby, both were measured, dies set and nothing, cases GREW in length…had to turn .010" off the shell holders to get desired results, as both are 'match grade' chambers at minimum SAAMI/CIP Spec.

Cheers.
 
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