I've gotten questions from various people regarding how to properly adjust the various reloading dies (decapping, sizing, belling, seating...). Rather than explain it individually each time, I'll write it one final time, and you can read about it here any time you like.
One thing you should always do is make sure your dies are CLEAN - a little WD-40, Kroil, CRC, Hoppe's, etc... on a Q-Tip works well. I do a quick cleaning of every die after every use. This maintains proper tolerances, load consistency, and keeps your dies and brass from being scratched up and ruined by foreign particles. Build-up on your dies (dirt, crud, lube, wax, ...) will change the way they form your brass cases or seat bullets. The dies that get dirty the fastest are the resizing dies and bullet seating dies (if you seat lubricated lead bullets). Keep 'em clean.
These dies can be used to knock the primer out of any case. They are useful to those who want to clean the brass with an exposed primer pocket. If you tumble after doing this be sure to clean any tumbling media out of the flash holes! They are also useful as a temporary fix for those who have resizing dies with missing decapping pins.
Why resize at all? When a cartridge is fired in a firearm's chamber, it actually stretches to tightly fit that chamber during powder combustion. After combustion is complete, it 'springs back' to a degree, but not enough to ensure that it will feed easily to next time you load it. Additionally, unless you have a tight custom chamber, the brass will have stretched so that it will not longer hold a bullet securely. These dies usually have a decapping pin to combine the decapping (depriming) operation with resizing the case.
These dies come in two types - neck only and full length sizing dies. The 'neck size only' dies are used for resizing the casenecks of bottleneck rifle cartridges that are fired in a bolt-action rifle (or bolt-action handgun, I suppose). This die only sizes the neck, and does nothing to the case body. Full length sizing dies full length size the whole case. Why are there two types? Well, the full length sizing dies can be used on cases that were fired in any firearm, while the 'neck size only' dies should only be used on cases that are used in the SAME (one particular) bolt-action firearm. Why? Because the case becomes 'fireformed' (customized) to that particular chamber, and may not feed properly into another. The reason you should only use this die for cases fired in bolt-action firearms is that other actions may not be strong enough to chamber the 'custom-fitted' case by themselves.
This procedure neck sizes 3/4 of the neck - not the whole neck. Why? By leaving about 1/4 of the neck unsized, it will help align the cartridge better in the chamber than if the whole neck was sized. This is an aid to accuracy.
I neck size only for a Rem 700 in .308 Win and a Win 70 in .270 Win. I resize about 3/4 of the neck. Since I started neck sizing only, I have NOT needed to EVER AGAIN full-length size my brass. I trim every time I load them, I anneal the necks every 5 firings, and I keep my loads 'reasonable' (I don't try to 'max' them out).
Accuracy? Well, I don't know about the Rem 700, because I never full length sized the brass. My accuracy has increased in the Win 70, but I don't know if that's because I (1) have become a better shooter (I think I have), (2) put better recoil pads on these rifles (contribution to #1?), and/or (3) finally found the loads it likes to shoot.
This can be used for cases fired in any firearm. Those seeking the ultimate in accuracy with bottleneck cases in bolt-action rifles may choose to neck size only. Some people advise that this also be done for all hunting ammunition - even for bottleneck cases used in a bolt-action firearm. I disagree, but urge whoever 'neck-only' sizes their bottleneck cases to run them through your firearm in a safe place ( - OUTSIDE for sure!) to make sure they feed properly.
Here we want to re-size the case 'just enough' so that it chambers easily in your firearm. If you just blindly resize it as much as the die will do, you risk pushing the shoulder back too far. This will lead to premature case head separation (thinning and separation of the brass down by the case head). In other words, you'll wear your brass out too fast, and risk 'splits' in your brass during firing. This is a definitely a 'bad thing'. Additionally, you are creating unwanted "slop" between the cartridge and your rifle's chamber if you resize the case too much.
These are used on straight-wall (mostly handgun) cases, and I suppose any case being loaded with a cast lead bullet. I've never loaded 'low velocity' case lead loads in any of my rifles. This operation is performed to prevent the case from "shaving" the lead from a bullet, or buckling the case.
When seating bullets in pistol cases, some people prefer to seat and crimp in two separate operations. It has been claimed that this increases accuracy. Maybe I'm just not good enough a pistol shot to notice the difference yet, but I seat / crimp in one operation when loading pistol ammunition. Bottleneck rifle cartridges only require bullet seating, but some people also crimp their rifle ammunition. The theory is that this gives more uniform neck tension. I feel that it damages bullets with no cannelure, and adversely affects accuracy. To ensure uniform neck tension on my rifle ammunition, I personally use a quality neck die, and polish the inside of the case neck with steel wool. To each his own ... the debate continues.
This can be a little tricky, but once you've done it, it all makes sense.
When seating rifle bullets, I use Redding Competition Seating dies, and feel that they were definitely worth the $65 I paid for them. Another thing you can do to increase accuracy in your loads is to "square up" your dies with the press ram. There are two approaches to this end, and I believe they both work equally well. If you're having trouble with non-concentric rounds, try these tips :
1. Place a large O-ring between your sizing die and seating die where the lock nut meets the loading press. It is possible that the lock nut on your die is a bit cocked, causing your die to be misaligned when it is screwed down tight onto your press. The O-ring should have a somewhat snug fit on the die body. Tighten the die down as normal. Be sure to tighten it the same amount each time you use it, or you will not get consistent case dimensions from session to session, assuming you removed the die. When you use the die, it will flex slightly (due to the 'give' in the O-ring) and automatically align the die (and therefore, your case) with the ram, allowing the die to straighten itself out if this is the problem. There was an article describing this in the VHA magazine, I think in the spring of 1999.
2. Mechanically square your sizing and seating dies with the ram by placing a square (that means the top and bottom are parallel to each other) piece of steel stock between the shell holder and die. Precision machined washers, precision tools, and even shell holders flipped upside down all work well. With the die in place, but a little loose, raise the ram. With light pressure on the die, tighten down the lock nut. This will align your die STRAIGHT in your press, and will decrease bullet runout.
Last updated : 02 January 2001