First off I think that the 280 AI is a great cartridge and I am not trying to say that one is better than the other. The two seem very close in performance. There are advantages and dis-advantages for both. The 284 Winchester yields virtually the same performance but in a shorter case which is more efficient. With a longer throat the bullet can be pulled further out of the case and the OAL becomes that of a long action cartridge. The 284 Win is one of the best 7mm cartridges for a Tikka T3 action. However factory ammo is limited for the .284 Win and is not found on the shelf very often. The 280 AI on the other hand is somewhat limited by the length of a Tikka magazine, maybe other DBMs as well. 280 ammo is readily available. Brass is available for both although I believe that the 284 Win goes out of stock more often.
I worked up a load for my 284 Win using the 162 gr ELD-X. The goal was consistent velocity and accuracy for hunting. This load is not a max load for this bullet. I compared my 284 Win load to Hornady's advertised ballistics for the same bullet in factory loaded Precision Hunter ammo in 280 AI.
My load for the 284 Win:
![Ballistic chart_resized.jpg Ballistic chart_resized.jpg](https://forumdata.rokslide.com/file/forumdata/data/attachments/558/558028-1844e9adff59f2d035d1786d91319a80.jpg)
Hornady's Precision Hunter 162 gr ELD-X in 280 AI:
![Hornady 280 AI cropped.jpg Hornady 280 AI cropped.jpg](https://forumdata.rokslide.com/file/forumdata/data/attachments/558/558033-98ca9a9fe4b9092386180bb605d852f9.jpg)
I worked up a load for my 284 Win using the 162 gr ELD-X. The goal was consistent velocity and accuracy for hunting. This load is not a max load for this bullet. I compared my 284 Win load to Hornady's advertised ballistics for the same bullet in factory loaded Precision Hunter ammo in 280 AI.
My load for the 284 Win:
![Ballistic chart_resized.jpg Ballistic chart_resized.jpg](https://forumdata.rokslide.com/file/forumdata/data/attachments/558/558028-1844e9adff59f2d035d1786d91319a80.jpg)
Hornady's Precision Hunter 162 gr ELD-X in 280 AI:
![Hornady 280 AI cropped.jpg Hornady 280 AI cropped.jpg](https://forumdata.rokslide.com/file/forumdata/data/attachments/558/558033-98ca9a9fe4b9092386180bb605d852f9.jpg)