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300 blackout case to the 221?

Not getting any response on reloading area so here goes.
Since the 300 is supposed to be based on the 221, can it be reformed into a 221?
Thanks
 
Would think you would have to turn several times while stepping it down? My guess is too much brass to get it all the way down to .22 without doing such??? Just guesses though. Best to scrounge a few cases and see where it goes. Surely I would think you would have to anneal fired brass before starting or it will fold/buckle over itself, might have to anneal new also???????? With all that work I would buy new Lapua and know what I had.
 
It would be a lot cheaper to make it, if turning wasn't necessary.

Someone who tried it said the length did come up a little short.
 
I tried 223 brass but it didn't work out well.

The parent case for 300 Blackout is a .223 case. A 300BO is essentially a straight-walled case created by cutting a 223 case at the point where the body and shoulder intersect. I believe that it is easier to form 221 Fireball brass directly from a .223 case. By using the 223 case you only need to bump back the shoulder (several small passes) and then trim the neck length to match your desired case length. The new neck is formed from case walls of 223 case (thicker material). Depending on your rifle's chamber you may need to either neck turn outside or ream inside to reduce wall thickness.

If you use a 300 BO case then you will need to form both the shoulder & neck, trim to length, and then still need to neck turn/ream neck.

I suspect that it is easier to gradually bump back an existing shoulder then it is to neck down a case that also requires creating a shoulder and neck. Additionally, using 300BO case will cost more because of extra cost of buying transitional dies required to neck down from .308" to .224" case as well as forming a shoulder.
 
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I had no trouble taking a 300 BO and running it in a 221FB size die and coming out with a formed case.

Good Feedback! Have you also made 221 cases from 223 cases? If so then based on your experience is one way better/easier than the other?

Thanks
 

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