.395" for a 450/400

[Smoke73]

I have been given two barrels by our local gunsmith due to there odd size of .395". They were sent to him by accident and due to border issues was told to do with them what he pleased. I intend to build a 450/400 3" double with these barrels but need some help with design. I am looking to shoot 400 grain WW. Their twist rate is 1-12". I would like to shoot at 2150 fps. I am learning but basically clueless about casting. I have been playing on the mountain mold site so have a few ideas. Main concern is not having to break the bank to start casting for this one oddball caliber. Any help would be great.

[rockrat]

I think the 450/400 uses bullets at .411", so I don't think it would work. The loading dies wouldn't size the necks down far enough, unless you have a custom chambering reamer made, then custom dies to load the rounds. You would end up with a 450/390 instead.

Now, if the barrels are .395" bore, the the groove might be closer to .401"-.403" and the 38-40 might work.

[Smoke73]

Yes I should have explained myself better. I will be having a custom reamer cut for chambering barrels and reaming blank dies.

[AkMike]

What donor action are you going to use?

[Smoke73]

I will most likely go with a Husqvarna Model 51 hammergun. My father taught me to love all things Husky as it wasn't long ago that his grandfather left Sweden.

[Nrut]

Are they McGowen barrels?
You stated that you wanted to run 400gr. cast bullets at 2150fps..
If you run grease groove bullets then you will need gas checks and no one makes gas checks that size that I know of..
I don't think that you can size down .411/.416" gas checks on a .395-7" bullet and make them work..
Maybe you can have a custom "check maker" made..
I would use paper patched bullets in a .395" myself..

RIP over at Accurate Reloading has done quite a bit of work with the .395" and he was the one who had McGowen make barrels in that caliber..
He used various cases for that bore size but not the 450-400 to my knowledge..
The one case that interested me was the 9.3X74R necked up to .395"..
His tests showed that he could easily excess 2150fps with his 420 gr. cast bullet using that case, but he was using a Ruger #1 which can handle higher presure than most doubles..
Here you'll find search results on his 400/395 Nitro Express..
http://forums.accuratereloading.com/eve/forums?a=search&reqWords=400%2F395+Nitro+Express+Cast+Bullets

Good luck with your project and please post results when you get it up and running..