Reloading firearm cartridges: Part 3
by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
- Trimming the neck
- Deburring the case neck
- Uniforming the case neck
- Primer pocket uniforming
- Straight-wall cases
- Tapered cases
- How to save time
First I want to thank everyone who is taking the design an airgun challenge seriously. We are seeing some thought put into your designs. And remember, the contest is still running until the end of the month. Now, on to today’s report.
This report on reloading is starting to attract some attention, as I hoped it would. Your comments have been instrumental in determining what I write about. I’ll start with a comment by reader Brent.
“So you don’t have to trim the neck with any tool separate than the Lee Loader? I guess the only other things I would need to get are a tumbler with some stainless steel pins and perhaps a scale if I wanted to experiment with powder charges. I do think you need to address leaving empty space in the case because that is a real no no with blackpowder because it tends to act as an explosive rather than a propellant then.”
I responded to him this way.
“Brent, The Lee Loader bypasses several steps that a careful reloader would do. Working on the case neck is one of them.”
Trimming the neck
When we talk about trimming a neck we are usually talking about a bottleneck cartridge, which is one with an angle from the shoulder to the smaller neck. The 5.56mm cartridge that’s used in the M16 rifle is such a cartridge.
This 5.56mm is a typical bottlenecked rifle cartridge.
There are several things that can be trimmed. If the overall cartridge case length is too long, a case trimmer can cut it back to length. We have a maximum “trim to” length that we watch and do not exceed. A case can be trimmed with a file, but a case trimmer designed to trim is much better. Some cases stretch fast and must be trimmed after every three loadings. The Swedish Mauser 6.5X55mm cartridge is notorious for stretching. After the second trim the case should be discarded and not trimmed a third time. It develops a weak spot about two-thirds back of the shoulder and will separate when fired if continually loaded. So you get about 6 reloadings from such a case, and less if you shoot heavy loads.
Deburring the case neck
After trimming the case neck you have to remove the burrs on the inside and outside. That’s done with the deburring tool I showed you in Part 2
After trimming to length the deburring tool is used inside and outside of the case neck to remove any burrs that remain after trimming.
Uniforming the case neck
Back in the 1960s some reloaders of bottleneck cartridges started worrying about making the thickness of every cartridge case neck uniformly identical. They felt the cases would then exert a uniform hold on their bullets and that would improve accuracy. Tools were built to not only cut the thickness of the necks uniform, but to also spin the cartridge to ensure concentricity of the bullet to the cartridge case. This is still being discussed and even done by benchrest competitors with results that are difficult to prove. One camp holds that all this is anal and has little effect on accuracy — the other camp swears by it. I side with the guys who don’t uniform their case necks. I am not a world champion benchrest shooter but I do save countless hours of time while reloading.
Primer pocket uniforming
There is also a school of thought that says the primer pocket flashholes need to be uniformly sized and all burrs on the inside of the case around the holes that were punched through need to be removed. So they drill them all to a uniform size and them deburr them inside. I do not do this. At the end of this section I will tell you a little trick that gets around all this (possibly) useless work.
Besides bottleneck cartridges there are also cartridges with straight walls. They are far more forgiving to reload. They don’t stretch much, but you still must measure their overall length. If they are rimless pistol cartridges, they stop in the chamber of the pistol on the mouth of the cartridge case. That is what determines the headspace of the cartridge and if the headspace isn’t right you can have a problem with exploding ammo. So the length of the case is important.
Rimmed cartridges like the .357 Magnum headspace on the rim. The neck of the cartridge gets folded over and crimped into a groove on the bullet to hold it tight when the pistol recoils. So case length is not as critical there.
The neck of the .357 Magnum case is crimped into the side of the bullet to hold it tight during the recoil of the pistol when the others are fired.
These cases last much longer than bottleneck cases. I get over 10 reloadings of them, even when I load heavy. But eventually the case mouth will crack from being worked back and forth. When that happens, throw it away.
Then there are a few cases that are neither straight, nor are they really bottlenecked. The .22 Hornet is an example of these. It has a gradual tapered shoulder that ends in an extra-long neck. You can argue that it’s a bottleneck, but it doesn’t act like one. It’s a rimmed cartridge, so it headspaces on the rim and not on the neck. This case is made of brass that is super-thin at the mouth of the neck and gets damaged very easily.
The .22 Hornet is an oddball case that doesn’t fit well into a category.
How to save time
Instead of doing all the tedious little things mentioned here, and other things besides, you can shoot groups of 10 shots, and, when a bullet strays outside of the main group, set that case aside and do not use it again. You end up with a set of cases that shot very well for whatever reason, and they will keep on doing the same, reload after reload.
When you reload you will make mistakes. Despite taking every care in the world, things won’t go right every time. You’ll load primers upside down or sideways, you’ll crush cases, you’ll strip bullets. You’ll load the wrong powder, making the cartridge dangerous.
For your mistakes you need an eraser! Reloaders call it a bullet puller and a kinetic puller like the one shown below is the easiest to use.
Oooops! The primer went in sideways and was crushed.
This bullet puller holds the base of the cartridge fast and is struck like a hammer on a hard surface, pulling the bullet by kinetic energy.
Phooey! Three reports already and we haven’t reloaded one cartridge yet. That’s coming soon!