Fire forming for 400 H&H

Pheroze

AH ambassador
Joined
Jul 6, 2013
Messages
5,234
Reaction score
8,832
Location
Ontario
Media
98
Articles
27
Hunting reports
Africa
1
USA/Canada
6
Member of
OFAH, DSC
Hunted
South Africa, Canada, USA
I am going to use the abundance of 375 H&H brass that I have to make practice ammo for my 400 H&H. This is my first attempt at fire forming brass to convert it to a different calibre, so any insight and advice is welcome.

My plan is to resize 375 H&H brass to the 400 H&H shape and then load a 300 grain Barnes .411 bullet over 77 grains of Varget for a velocity of about 2576 fps according to Quickload. Hopefully this will provide me with a more available source of practice ammo. Please let me know your thoughts.

Pheroze
 
Run 375 H&H brass thru a 375 die then directly into your 400 H&H die and be sure to use plenty of lube but not too much to cause dents and you should be ready to go! proper brass for Quality Brass is
available when you head to Africa. I have one built by Kevin Weaver and it is a shooter with both North Forks and A-frames 400 gr. I've used Hunter and Varget and both do well. I have destain for Barnes bullets due to fowling and inconsistent game performance (I know.....HATE MAIL to follow). and much prefer heavy for caliber bullets. The beauty of the 400H&H is very little difference in recoil compared to 375 H&H.
 
Last edited:
Run 375 H&H brass thru a 375 die then directly into your 400 H&H die and be sure to use plenty of lube but not too much to cause dents and you should be ready to go! proper brass for Quality Brass is
available when you head to Africa. I have one built by Kevin Weaver and it is a shooter with both North Forks and A-frames 400 gr. I've used Hunter and Varget and both do well. I have destain for Barnes bullets due to fowling and inconsistent game performance (I know.....HATE MAIL to follow). and much prefer heavy for caliber bullets. The beauty of the 400H&H is very little difference in recoil compared to 375 H&H.
Thank you

I too have North Forks and A Frames set up with my head stamped brass. I really like this calibre.

I am apprehensive about the initial shot with the reformed brass as it looks different even after running it through the 400 die. I appreciate reassurance!
 
What are your thoughts on annealing of the neck & shoulder prior to running the cases through the 400 H&H die? Also would you recommend firing a fire forming load prior to the first real load?
ps in what very little case forming I've done, better results came from fire forming than by using an expander die for the intial neck up.
 
What are your thoughts on annealing of the neck & shoulder prior to running the cases through the 400 H&H die? Also would you recommend firing a fire forming load prior to the first real load?
ps in what very little case forming I've done, better results came from fire forming than by using an expander die for the intial neck up.
I have never annealed, but it seemed to accept the die easily. I use imperial wax and it seemed to be no problem. It has a taper still that needs to blow out.

Quivkload shows this powder charge and bullet to have very moderate pressure. I am not sure what else I would use to otherwise fire form the case
 
You can either size and fire a 40cal projectile or a compacted wad of toilet paper, some will put some corn meal on top of the powder and then toilet paper. Either will work. Some cases require two firings to form properly. I’ve loaded cast projectiles on an appropriate powder charge and use as close up hunting round or just a plinking round when forming 300 wind bag into 280 nitro express.
Gumpy
 
Your plan should work. If you get some stretching on the case web, you can size it to something bigger, then back down just till the bolt closes. You shouldn’t have to being belted, but I’ve had to do it to a 303 before.
 
After re-sizing the 375 H&H brass in your 400 H&H sizing die you will see a slight visual wrinkle in the neck this is left over from the 375 shoulder. My first loads with the re-sized brass were a bit softer then yours using the same .411 Hornady 300gr SP as the price was right... Those first loads were mainly used for shooting drills and to shoot out the wrinkle left in the neck after re-sizing, though I can't see and reason why you could not hunt with the visual wrinkle present. You will find the re-sized 375 brass to be a few thou short but the neck is so long it will not matter ....
I later worked up a Barnes .411 300gr TSX load with my which I have used for pigs and elk and have no problem hunting with the re-sized 375 H&H stamped brass any where a proper head stamp is not needed further saving my proper 400H&H head stamped brass for travels far away ....
 

Forum statistics

Threads
64,224
Messages
1,414,790
Members
129,270
Latest member
RobertaHir
 

 

 

Latest profile posts

wheelerdan wrote on Jager Waffen74's profile.
Sir, I think I have been writing to you about the purchase of the HK 639 rifle under an email "Tt Jake." If this is you, then I am truly interested. I am just trying to verify identify. Tt Jake is asking for a cash transaction. No disrespect intended, Just trying to verify who I am talking to. Thank you. Respectfully. Dan
Gary C wrote on HuntingFreak's profile.
Hey my friend, I am returning to SA for a Cape Buffalo hunt in June 26. My outfitter has suggested Highveld but I have read some poor reports. Wondering how satisfied you were with your mounts from them? Thanks in advance.
Finally back to somewhat normal I missed reading the messages and posts
Remember I will be at the ISE show in Denver Colorado for 8-12 January, and after the show I will be available for meetings anywhere in the USA I will traveling around to meet with old and new clients, let me know and we will set up a meeting!
Beautiful Aardwolf for our Spanish client and good friend Alberto
WhatsApp Image 2025-11-12 at 17.27.22 (2).jpeg
 
Top