This is going to sound a bit odd, but I am having a pure custom built on a Magnum LH MRC action... I have the stock blank from Roger Vardy, and it is with my riflesmith, along with the action and proper floor metal. Here is the question:

I was looking hard at the 400 H&H but it appears that cartridge was a pure flash in the pan. I can get brass and dies, but the correct weight projectiles are extremely scarce in .411. It appears that Nosler, who was going to make the 400-grainers for the new round, changed their minds.

So: what would you build on that action, which has a 3.625" magazine box? It being pure custom, I don't want anything 'vanilla' (like a 375), but am open to advice from those far more knowledgable than I am.

I already own a 458 Lott, fwiw, and with a fused neck vertebra, certain hard kickers are out of the question. (The 416 Taylor was a consideration as well, but the bolt face is wrong and the box is too long)...

Thanks in advance, guys...

Seems 416 Rem mag is the most logical with 404 Jeffery in second place.

I did a 404 Jeffery on my LH MRC action.

If you dont want Vanilla there is

.40 Newton
400 A-Square
416-375 Weatherby
416 Dakota
416 Hoffman

416 Dakota or 416 Remington

The 400 H&H is hardly a flash in the pan. As with all things H&H it is well thought out. It will propell a 400 gr bullet at +-2500 fps, which many decades have proven to be all you need. The case design shares the H&H DG design of being belted and well tapered to ensure headspace and feeding. While Barnes and Hornady make 300 gr bullets, the bullet of choice is the 400 Woodleigh. It is also an excellent cast bullet cartridge. My own build is a rebored 300 H&H classic with Rigby style steel bottom metal (no hinged floorplate to open at the wrong time) and an extra cartridge and a generous French walnut stocked executed by a former employee of a well known ex Wyoming single shot rifle firm. It will drop 3 in 1 MOA with only a 1-4 Leupold. If you have a Magnum action make a real magnum.
Suggested reading:
http://www.chuckhawks.com/400_HHMag.htm

I'm shooting the 400H&H as well in fact it is leaving for Zim in 2 days. You are right the .411 dia bullets have been tough to come by but they are getting better. CEB makes .411 bullets in 320,370 and 400 grns. Northfork in 360 Barnes makes bullets in 300 and 400grns Woodleigh makes them in various sizes Hawk makes traditional bullets in .411 and for practice with reduced loads any of the bullets made for the Win 405 and the 450-400 will work. Barnes has been waiting for pressure data from CIP and they claim they will be loading 400H&H in their Vor-Tec line of bullets. Superior Ammo have been making ammo for the Gulf Breeze customers in FL, they are Dakota reps has been selling alot of this caliber and their clients and their 400H&H have been to Africa numerous times. NECG has chambered more than a half a dozen 400's they did mine and they can ream your chamber if need be.
I personally have had success with the Barnes 300gr on a cow elk and boar and have put numerous rounds down range with the various projectiles mentioned above.
The loads going to Africa with me are 400gr CEB solids and 370gr Ceb NC they are both moving around 2400fps using Hodgdon's Varget powder.
Every thing that I have put through this gun has shot well the recoil is very manageable and feeds like a charm I think the cartridge design has a lot to do with it. If you are a handloader and looking for something different I recommend.
Good luck in your quest for a new cartridge.
Below the 400H&H with 480gr Hawk Bullet and the 375H&H with a 300gr TSX. (I should update the pic with CEB bullets for the gang)

For my 400 I re-barreled a new win mod 70 375 i had the mag box changed it now holds 4 down

Seems like a 404 Jeffery would work but unsure about what modifications may be necessary to bolt face and mag. box, etc. and costs.

Loading components are available in the U.S.A., Norma and Hornady Brass....bullets are available from North Fork, CEB, Barnes, Hornady..Hornady and Norma make loaded ammo.

404 would be my first choice by far...classic round that can be loaded to higher velocity, if desired, than a 416 Remington or 400 H&H.

A wildcat simply a 375 H&H necked up to .423 (not blown out) would be lovely. I'm sure this wildcat has a name....

45-70 and Zephyr, thanks for the information and the recomendations. I hadn't made any definitive decision to change calibers, I was just somewhat frustrated by what I perceived as a lack of 400-grain projectiles in the right diameter.

I have been handloading and casting for a bit over 30 years; in fact, I have several moulds that are nominal .410" - .411". Maybe with pure lino I will get lucky and get them to .412".

I will look at CEB and Woodleigh. I sincerely thank both of you for the help, and the others of you for your recommendations.

I have a 400 H&H as well, and although it has been dormant for a while now, I can't imagine a bullet that is missing for what the cartrige was intended to do. It's a hammer, not a scalpel.