Asking for loads but mainly powder and bullet combos? Cases and dies are recommended to me by the gunsmith. Pistol bullets being favored for varmint and plinking loads. Any experienced with the 400 Whelen here? TIA, Be Well, Packy

Pack Can I ask if you are going to use cylindrical 06 brass ? I have a 375/06 Ackley Imp and I use 30-06 brass. Not much shoulder there before fireforming. I have obtained the best fireforming with a cast bullet seated out to firmly jam into the rifling with about 12 grs of Red Dot. Cases come out nicely formed and zero case loss.I had toyed with the idea of a 416/06 IMP but even with the IMP case there isn't much shoulder to headspace on. I'm very happy with the 375/06 AI with lots of good 375 cal bullets at good prices

There is plenty of load data on the 400 Whelen thread
under Big Bores

As for fire forming, I used to do that, but to save time, just expand the shoulder first to .458 and then resize normally.

If I was recommending the 400 Wheelen I would also recommend the rifle.

F. Guffey

I am going to have dpcd make for me an expanding die to make 30-03 new brass into some long lasting cases for my new rifle. Per dpcd I am ordering a die set from CH4D in the G&H style. Be Well, Packy

I still get questions every month on the 400 Whelen, from guys who are still confused and interested in it. They have usually the, what is by now, volumes of information on it, starting in 1923 or so. As I have said before, History is great, but there is so much information, suggestions, and versions of it, that it is like drinking from a fire hose, and you still won't know what to do. Every one of them is really scared of "Headspace" on the 400. Data Overload. No need for fear; it is a very easy wildcat to tame.
So I will give the Executive Summary, on How to Get and Shoot the Right 400 Whelen.
1. Get the 400 Whelen reamer from Dave Manson, specify the G&H version. It has a 458 shoulder, More than enough, and the reamer is .4585 OD.
2. Get the reloading die set from CH4D; specify the G&H set; call them; they know exactly what to do.
3. Get or make (I make plugs for Lee expanders) an expander that will make any 30-06 case into a .458. This is easier than fire forming with pistol bullets, but that works too; you have to jam them into the lands. Anneal or not; some brass needs it.
4. Size and load as normal; plenty of loading data out there.
5. Get the barrel from Douglas; specify their .410 barrel, with one in 12. You can shoot any .410/411 bullets made for the 450-400, 405 WCF, etc, in it. Even 41 mag pistol bullets. Some guys ask for a lower quality barrel. No.
6. That's it. I have six of them in process now.