Hi all
I am in the process of working up a couple loads using 117 grain SST and 87 grain ballistic tips. Is there anyone using 7828 ssc or hybrid 100 for either of these that could give me a little help?

Check with your powder mfgs website for recommended loads.

This is all I could find on your .257 Ackley Imp. http://www.reloadersnest.com/frontpage.asp?CaliberID=34 Didn't see the two powders you have listed.

If you can seat the 117gr SST one caliber into the case, for an OAL of 3.166", QuickLoad suggests a MAX load of 52 grains of IMR7828 will give right around 47,000psi. Nosler does not list an 87gr Ballistic Tip, so I'm going to presume you meant the 85 grain offering. Again, seated one caliber deep, for an OAL of 2.976", QuickLoad suggests a compressed charge of 56 grains IMR7828, generating just under 47,000psi.

I would consider 47gr of Hybrid 100V to be about max for the 117gr SST and 50gr of Hybrid 100V to be about MAX with the 85gr BT.

Please back these off 10% and work up carefully. Since you are working with a wildcat, there simply isn't a lot of data out there, especially for the latest powder and bullet combinations. As a very rough rule, you can use middling charges for the parent cartridge as a starting point, working up loads while being very diligent about checking for pressure signs. It's best to proceed slowly, when navigating uncharted waters.

I thank-you all very much for the starting point and I checked the bullet weight my dad bought and you are right 85 gr

I would say that 7828 is too slow for the .257 AII like Varget for the lighter bullets and 4831 is about as slow as you need to get top speed with the heavier bullets. Both Hornady and Seirra have detailed load data.

Scroll to the bottom of this page to the "Similar Threads" section and click on the several previous threads/posts on the 257 Robt's AI.

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A quick update
I worked up loads for both the 87 grain and 117 grain bullets
Using hybrid 100v and Imr7828 ssc 3400's for the 87 and 2900's for the 117
And each give me silver dollar ten shot groups at 200 letting the
Barrel cool every 5 shots. Very very happy with both
No strings and no signs of pressure even when micing cases