Fire forming: .375 H&H Magnum to .423 (404) Jeffery

Very interesting, and I didn't think that this could be done safely. I can understand that the case wall in front of the belt could expand to the chamber diameter, but does the belted part (.532) also expand to the Jeff diameter (.545), or is the fireformed cartridge still a bit slim around the case head?

How far down the case do you anneal?

Would you care to make a guess on how many times you have reloaded such cases?

/cmk
 
Very interesting, and I didn't think that this could be done safely. I can understand that the case wall in front of the belt could expand to the chamber diameter, but does the belted part (.532) also expand to the Jeff diameter (.545), or is the fireformed cartridge still a bit slim around the case head?

How far down the case do you anneal?

Would you care to make a guess on how many times you have reloaded such cases?

/cmk
CMK, I need to measure the belt diameter to give you a diameter in this regards. I anneal the neck part, and take care not to anneal to low down to the bottom of the case. I have been shooting these cases the past few years and still reload them.
I have purchased new Hornady brass I am using for my hunting these days. As pointed out, I needed brass that time and it was not available, so I had to make a plan. (y)(y)
 
I have known about fire forming brass in this manner for several years but have never done it. From reading other posts on reforming 375 H&H to 404 Jeffery I was lead to believe that while it is serviceable the overall length is just a little short. But as Gert mentions when your in a "pinch" this procedure is a good work around.
 
I have known about fire forming brass in this manner for several years but have never done it. From reading other posts on reforming 375 H&H to 404 Jeffery I was lead to believe that while it is serviceable the overall length is just a little short. But as Gert mentions when your in a "pinch" this procedure is a good work around.
 
As I pointed out, these fire formed brass that was a belted magnum head-spaced on the belt..after fire forming it head spaced on the shoulder. I never has a failure when these fire formed brass was shot in my 404 Jeffery...Johan Greyling is still using this brass that we fire formed. Johan Greyling is my mentor who assist me in most of the gunsmith training I do after my full time job. Some interesting phenomenon about the Walter 404 Jeffery barrels is that the diameter measures .418 inches....(y)(y) I contacted Walter Barrel company, to there knowledge they were not aware of this. We have previously ordered a few Walter barrels in the 404 Jeffery caliber..thus we noticed the diameter to measure .418 inch. A good friend Hansie Minnaar, owner of Stewarts Core bonded bullets has the same experience in this regards, he had to make bullets for the 404 Jeffery owners in a .418 inch diameter...
 
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Gert, this is most interesting. I have recently gotten myself a 404 Jef, but haven't had the ability to fire it yet. It has a Lothar Walther barrel. I believe the previous owner used regular Hornady DGX bullets without any problems. As these have a bit of a bad reputation, I thought I'd go with A-frames and Woodleighs, so I purchased a bunch of those. Perhaps I should have my barrel slugged before doing any major shooting?

At least I should probably do so before ordering a mould to start casting my own bullets...

Sorry for getting off-topic.

/cmk
 
Gert, this is most interesting. I have recently gotten myself a 404 Jef, but haven't had the ability to fire it yet. It has a Lothar Walther barrel. I believe the previous owner used regular Hornady DGX bullets without any problems. As these have a bit of a bad reputation, I thought I'd go with A-frames and Woodleighs, so I purchased a bunch of those. Perhaps I should have my barrel slugged before doing any major shooting?

At least I should probably do so before ordering a mould to start casting my own bullets...

Sorry for getting off-topic.

/cmk
CMK, , slug your barrel, that will always be the first step when you get hold of a rifle you want to use. There are numerous brands of bullets to shoot in your 404 Jeffery. North-fork bullets , core bonded being the premium range.. I attended a buffalo hunting course conducted by Dr. Kevin Robertson in the Kruger National park ,using my 404 Jeffery open sights during the shooting trails..with great success..Dr. Kevin believe in the North Fork cup/core bullet in a 450 gn for the 404 Jeffery rifle as the best combination to hunt buffalo and..they use Dzombo solid bullets as their choice for elephant hunting/culling. I purchased 450 gn Steward core bonded bullets from my friend Hansie Minnaar to use in this upcoming hunting season , I need to hunt Blue wildebeest bulls ...
 
Hi Gert, when you refer to these as practice rounds are you shooting cast or jacketed bullets for practice?
 
Impala bullets are the cheapest to use as practice rounds...I moved away from using cast bullets...it seems to be a hassle when reloading..Impala bullets are excellent to hunt with as well..I will be hunting impala bullets this upcoming hunting season..the larger bore seems to favor the use of Impala bullets...(y)(y)
 
Reviving an old post...shortly after I commence using Impala bullets on the Dangerous Game shooting days organized by BASA , I really saw why the large bore calibers is so effective when hunting game like large bodied plains game animals like Giraffe/Eland /blue wildebeest ..the Impala bullet punch an exact caliber hole into the skin of the animal thus providing a good blood spoor .
Fast forward a few years, I am still using the .375H&H Magnum fire formed to 404 Jeffery brass when shooting on club days and now have a lot of great quality 404 Jeffery cases for the next twenty years....
But the fire forming exercise really got me to understand how brass can flow when under pressure and heat, something I did not understand previously. Every day we learn new things about processes and materials... (y)
 
Reviving an old post...
Fast forward a few years, I am still using the .375H&H Magnum fire formed to 404 Jeffery brass when shooting on club days and now have a lot of great quality 404 Jeffery cases for the next twenty years....
But the fire forming exercise really got me to understand how brass can flow when under pressure and heat, something I did not understand previously. Every day we learn new things about processes and materials... (y)
Hi Gert, do you have an estimate of how many times you've reloaded the fire-formed 375 cases?
 
Hi Gert, do you think this process can be used do convert 300WM brass to 308 Norma Magnum brass?
Or would you just use a FL resizing die?
 
Jorg, looking back at the fire-form procedures Johan Greyling assisted me with, I believe you can use the FL resizing die as well as first anneal all the cases before you fire form..follow the process Johan Greyling assisted me with as described in the thread of the .375 to the 404 Jeffery forming..keep in mind, at no stage is it dangerous since the fire forming is in a rifle barrel, at low pressures and use maize to fill the cases as well...
You might have to do it two or three times to ensure a complete forming...but you will be able to do it.

I think the MP200 powder for pistols at 15grains is a safe way to go. Please give some feedback of your fire forming process..the usual safety precautions like safety glasses , ear protection, safe environment where you can do the fire forming alone is always a good thing to do.
 
Jorg, looking back at the fire-form procedures Johan Greyling assisted me with, I believe you can use the FL resizing die as well as first anneal all the cases before you fire form..follow the process Johan Greyling assisted me with as described in the thread of the .375 to the 404 Jeffery forming..keep in mind, at no stage is it dangerous since the fire forming is in a rifle barrel, at low pressures and use maize to fill the cases as well...
You might have to do it two or three times to ensure a complete forming...but you will be able to do it.

I think the MP200 powder for pistols at 15grains is a safe way to go. Please give some feedback of your fire forming process..the usual safety precautions like safety glasses , ear protection, safe environment where you can do the fire forming alone is always a good thing to do.
Thank you Gert. I have never attempted fire formìng ever but will have too maby in the future. My 308 Norma brass is getting little and so scarce too find and expensive. I only have a FL die and brass does not seem to last too long.
 
 

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Wow, thanks Gert. Not badly priced. The last time I saw a couple of years ago was R1200 for 50. I will order from them.
Weereens, baie dankie. Ek wardeer
 
Wow, thanks Gert. Not badly priced. The last time I saw a couple of years ago was R1200 for 50. I will order from them.
Weereens, baie dankie. Ek wardeer
Jorg, dit is `n plesier, I do not thinkyou will get it for a better price since it is a specialized caliber..I noticed the USA military are converting from the .338 Lapua to the .308 Norma Magnum ...
 
John , good to hear from you, thank you kindly, yes it was a busy period the last year or so..but I am making more time to get to the forums and working on rifle builds..I am currently complete the .375 H&H Magnum since I had to replace the old barrel and now have to fit all the quarter rib and front sights again..have been working at it the past two days ..
 

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