A friend of mine recently introduced me to the .400 corbon round. I reload a lot of 40 S&W and have an over abundance of .45 ACP brass on hand. That got me to thinking. Is it possible to neck down .45 ACP brass to .400 and convert it to .400 corbon? Has anyone ever done this before?

I don't even have .400 corbon case specs in my Lyman 48th edition reloading handbook, and Hodgdon's website doesn't list .400 corbon reloading data. Does anyone have data on the case specifications and reloading data or know where I can get it? Also, does anyone think it's possible to neck down .45 ACP cases to .400?

I appreciate the help and advice.

I have a .400 CorBon and it is a simple procedure to neck down .45 ACP brass to .400 CorBon with a single pass in the .400 sizing die. If you already reload rifle cartridges you will know how to deal with this cartridge. Don't forget to use case lube since the sizing die is not a carbide ring for straight walled case type of die. And, I suggest dropping a resized case into your .400 CorBon barrel and checking the headspace before doing a whole batch. It's easy to set the shoulder back too far. However, I wouldn't resize .45 ACP brass at all unless you are planning on shooting light loads, which is not really the point with a .400 CorBon. Or, use only brass marked .45 ACP +P, which is probably harder to find than .400 CorBon brass. Also, the later .400 CorBon brass uses the small primer pocket (the original brass used large pistol primers). I haven't tried to buy .400 CorBon brass in some time but had no problem doing it.

Lastly, I recommend getting the Lee Factory Crimp die for the .400 CorBon as any attempts to crimp effectively the CorBon round will cause shoulder bulge with any other die. You will probably also want to put a stronger recoil spring on your 1911.

Here is some load data but proceed with caution.
http://www.handloads.org/loaddata/default.asp?Caliber=4...Order=Powder&Source=

This cartridge is really only interesting with the 135 grain to 155 grain bullets as heavier bullets don't get you much more than a .40 S&W.

Thanks a lot for the info. I've been gone a few days so sorry for replying so slowly.

I didn't know that full pressures required +P brass. If that's the case I'll probably just get .400 CorBon brass & gear and go from there. It kind of sucks because I have several thousand .45 ACP cases laying around, but I'll find some use for them. :-)

I've used the Starline 400 Corbon brass with good results, but have also shot a lot of resized (non +P) 45ACP brass in the Corbon without any problems. I tend to keep the loads in the ACP brass on the lighter side, although I've tried some near-max loads without any problems either.

With a lot of ACP brass now coming with small primers, I sort it out and set it aside to be reformed to 400 Corbon. I've also scrapped the few Corbons with large primers I had so now all my 45ACP reloading is with large primers, all the 400CB is with small. Keeps things simpler with the Dillon SDB.

Bud