Newbie Reloading Question

[JoeSoap]

So for reloading various big bore african cartridges, I see there is a sizing die (full length or neck), a bullet seating die, a crimping die, and a trimming die (and a special die for belted cartridges to prevent the bulge), a expanding mandrel die. I understand the first two (sizing and seating), but is the crimping die really needed and the trimming die? No idea about the expending die…

I especially dont understand the trimming die, Lee says it cuts the mouth square. If you have a Henderson electric trimmer is this die unnecessary? also I thought the Henderson or Giraud electric trimmers intentionally didn’t cut the mouth square. So I am a little lost as to what is necessary.

 

[Andrew NOLA]

Joe, the sizing die will have a button on the depriming stem that will expand the case mouth to the correct diameter to seat a bullet. You don't need an expanding mandrel. I have used those when I turned the necks for benchrest competition. Not needed for reloading hunting rounds.

On a round that uses a crimp, generally the seating die will also crimp the case mouth into the cannelure. The die will come with instructions on how to do that. I like to crimp separately using a Lee crimp die - they are not expensive. However, not necessary.

I have never used a special die for belted cartridges - I do full length size every case I reload - I do not neck size. If you full length size, the case is exactly the same each time you shoot. Consistency is the key.

I use a Forster trimmer to trim necks. I used to use a Giraud when I shot a higher volume. Both gave me square necks. I have never used the Lee trim die. I would not spend the money on the Giraud for loading for hunting - you just will not load enough to justify the cost.

Buy a Hornady or Sierra reloading manual first and read the sections on reloading. A wealth of really good basic instructions in there.

Mainstream dies in order of my preference, Redding, RCBS, Hornady then Lee. I also really like the redding T-7 turret press - solid lockup and you can set up 2-3 sets of dies in it so you don't have to keep changing them out. I also use a RCBS chargemaster to weigh and throw powder. Satern powder funnels, which are bullet diameter specific. A good set of Calipers and the Hornady Lock‑N‑Load® Bullet Comparator & Inserts (so you can measure loaded cartridge length from the base to the ogive, more preesice than measuring the overall length). I like the RCBS Hand Priming Tool.

It's really not complicated (although you can make it as complicated as your OCD demands).

 

[Ridge Runner]

So for reloading various big bore african cartridges, I see there is a sizing die (full length or neck), a bullet seating die, a crimping die, and a trimming die (and a special die for belted cartridges to prevent the bulge), a expanding mandrel die. I understand the first two (sizing and seating), but is the crimping die really needed and the trimming die? No idea about the expending die…

I especially dont understand the trimming die, Lee says it cuts the mouth square. If you have a Henderson electric trimmer is this die unnecessary? also I thought the Henderson or Giraud electric trimmers intentionally didn’t cut the mouth square. So I am a little lost as to what is necessary.

Hope this helps:

Trimmer: used to trim the neck/mouth of brass to get the case to proper length as shown in the reloading data of the cartridge being reloaded.

Sizing/Resizing Die: generally includes deprimer. Used to deprime the brass and resizes the neck, and case. The neck and case is stretched/widened after being fired, this die reshapes the brass neck/mouth and case back to proper dimensions according to the cartridge reloading data.

Expanding Die: is set to barely flare the case neck/mouth to ease the start in seating the bullet.

Bullet Seating Die: generally also crimps the case to the bullet. Crimping helps keep the bullet of ammunition in the magazine, or second barrel, from loosening under recoil. Some die set don't include a crimp die or the crimp made by the bullet seating die doesn't provide a tight enough crimp thus a separate crimp die needs to be used to crimp the bullet and case more firmly.

 

[Andrew NOLA]

Ridge Runner is correct - on straight wall cases, you do need a seperate expander die that flares the case mouth to accept a bullet. On those cases, the sizing die does not do that. The expander die will come in the set.

My description is accurate for bottle neck cases, like 458 WM, 404 Jeffrey, 416 Rigby, 375 H&H, 375 & 416 ruger, etc . You don't need a seperate expander die for those. The term "mandrel" gave me flashbacks to benchrest.

 

[JoeSoap]

Thank you @Andrew NOLA and @Ridge Runner this was very helpful, your answers are greatly appreciated. Happy New Year!

 

[shootist~]

also I thought the Henderson or Giraud electric trimmers intentionally didn’t cut the mouth square. So I am a little lost as to what is necessary.

The Giraud chamfers / deburrs the case mouth both inside and outside at the same time it trims the case mouth - nice and square. A wonderful machine to have, but it is indeed expensive with added expense for each quick-change caliber conversion.