How to reform .45 ACP cases into .400 Corbon

I purchased a 1911 in .45 ACP customized by Bob Coogan that came with a fitted .400 Corbon barrel. I have never used the .400 Corbon barrel because of the scarecity of factory ammo and because I was not set up to reload the round. I recently read a post on a internet forum that stated .400 Corbon brass could be formed using .45 ACP brass. Since I have buckets full of .45 brass and a .400 barrel I figured now is the time to give this round a try.

Anyways, I would like to start reloading but am not sure how to form the brass or which die set to purchase. Any recommendations and guidance would be appreciated.

Mac

When I did this I just rolled the brass over my rifle lube pad and ran them into my .400 Corbon sizing die.

I haven't done this in years because I was underwhelmed with the results. My .400 Corbon barrel and heavy recoil spring have been in a sandwich bag somewhere in a box of gun stuff ever since. YMMV.

For forming .400 Cor-Bon, I've had the best results with either new or once fired Winchester or Federal brass, since they are the thickest of the commercial brass. Just lube it, after inspecting for dings on the case mouths, and then run them through the sizing die. That's all there is to it.

Any case with a case mouth ding will crumple when it's sized down. You'll also lose an occasional round due to dimples, etc. The newer the brass, the better the results.

I also chamfer the inside of the newly formed case mouths to facilitate bullet seating.

Hope this helps.

Fred

I haven't done this in years because I was underwhelmed with the results.
Were you underwhelmed specifically with the forming of the cases, or the cartridge in general? I'd be interested to hear what exactly was disappointing.

For me they just didn't do anything a 185gr .451 bullet couldn't do just as well. They didn't feed any more reliably and didn't shoot any better. The short case necks mean there's not a lot to hold the bullet and setback was always a worry with a cartridge that was already running at a higher pressure.