A reloading die is -in basic principle- just like any other die that is used to produce or shape an item. A spent case has been deformed by the explosion that has taken place inside and a die will be slid around the case, pushing it back into shape by great force, provided by a reloading press. That’s the theory, but dies are now used for a multitude of different tasks that are performed with a pressing motion, using great force. Often, you buy dies in a set for your basic set-up, after which you can buy separate dies for specific tasks.
Often, a die set will consist of two or three dies. The latter is mostly used for pistol and revolver cartridges. The reloading dies featured in such a set are:
- Resizing/decapping die
- Expander (flare) die
- Bullet seating/crimp die
The resizing/decapping die will compress your case back to standard size. Inside, there’s a hardened pin that will push the spent primer out of the case while you’re sizing. You’re actually performing two actions in one movement.
In order to push the bullet inside the neck without deforming or damaging it, the neck should be flared beforehand. Think of it as making a funnel shape that’ll make it easier to push a flat base bullet inside the neck. This is what the expander die does for you.
And with the bullet seating/crimp die, you will push the bullet firmly inside the neck to exactly the depth that you need. Sometimes, this will be enough, but often the neck needs to be crimped around the bullet. This is something where the die you use will be specially designed for. When a taper fit is needed, the neck will be crimped with a taper, getting smaller towards the top. However, bullets with a cannelure or groove (often for pistol or revolver), need a roll fit, where the edge of the neck is rolled into the groove in the bullet. Both methods require their own specific set of reloading dies.
Rifle cartridges often need a two-piece reloading die set, consisting of:
- Resizing/decapping die
- Bullet seating/crimp die
As you can see, the expander die has been left away. That’s because most of the time, it’s not needed to flare the case mouth as rifle bullets feature a tapered boat tail base.
When we’re looking at reloading dies for rifle cartridges, there are different sets you can choose from. For instance, there are full length reloading dies, that’ll resize the whole case from top to bottom. However, you can also use neck dies, that’ll only size the neck of the case. The advantage being that the material of the case isn’t stressed as much, giving you a couple of more reloads from it. But… the rifle shouldn’t be critical when doing this, such as semi-automatics are. For those tight chambering rifles, sometimes even full-length dies aren’t enough. That’s what small base die sets are for. They compress the case even tighter for small tolerance rifles to prevent jamming. Another type of die to take note of, is the top-of-the-shelf self centering die with changeable neck bushes that’ll allow you to finetune the interference fit between the neck and the bullet. It’s something that can give top shooters the edge in accuracy.
Besides the die sets above, there are multiple different single dies available. For instance, if you want to remove the primer before cleaning your case, you can do this with a deprimer (decapping) die, without damaging a combined sizer/decapping die with a fouled case. There are powder checker dies that will help you check if you’ve got the correct powder load inside the case before pressing home the bullet. It shows if the case is empty or maybe even double loaded. Lock-out dies to exactly the same, but will also block a progressive reloading press if your load isn’t correct. Continuing with the single dies, there are bullet feeder dies that’ll place a bullet in the case, but won’t seat it, nor crimp the case. And bullet pulling dies can be quite helpful when you need to remove the bullet from a cartridge with a damaged case of a doubtful powder load.
You should never skimp on your tooling. Ever. And that’s why you should be buying reloading dies that are top notch quality. We’ve only sell the best dies from brands that are well-known for their quality products. Why? Because the quality of the die will greatly determine the quality of your reloaded ammunition. Great dies will give the best uniformity and consistency. And as an added bonus, quality dies not only give you the most accurate ammunition, they will last the longest too. It really pays when you go for quality.
For pistol and revolver cartridges, the die sets are often made from tool steel. Hard and durable steel that’ll have no problem shaping the soft brass of the cases. But it’s a different story altogether when we’re talking about bottleneck cases for rifles. For these, the sizer die should have a tungsten carbide bushing, which is even harder than tool steel and is yet more durable too. Without a tungsten carbide bushing, the bottleneck case will get stuck solid inside the die, without any possibility of getting it out without damaging it. The forces are that great, that tool steel would wear quick too. Tungsten carbide will be far more durable. That’s the reason why you often pay a bit more for rifle dies.