Trimming brass sucks. It’s got to be the most tedious and time consuming part of reloading rifle ammo. Undoubtedly the step that all reloaders would like to skip. Every other stage is practically automated in comparison and at least somewhat exciting. Seating new primers: we got explosives. Loading powder: flammable materials and once again explosives! Seating the bullets: it’s ready for action! All very satisfying. If I didn’t have to trim my brass the world would be a happier place.
If you asked ten different reloaders what they used to trim their brass it wouldn’t surprise me in the least if you got a wide variety of answers, possibly ten different ones. Most I suspect have managed regardless of their choice to figure out how to make their particular method reasonably consistent and efficient. They may have managed to create an efficient system with more mundane trimming tools and I suspect this is what most reloaders often default too. Working to perfect their particular method to work best for them. Others may spend more money (potentially a lot) on more complicated, quicker and presumably precise devices. I have researched just about every device used for trimming brass with very few (and expensive) exceptions and they all appear to have their strength and weaknesses. Now I haven’t purchased all of these devices and tried them out personally, I’m not made of money after all, but I can say with good confidence that they all appear to suffer from the same weakness: precision and consistency. Nothing would please me more then to be proven wrong and have someone point me in the direction of the holy grail of brass trimmers. Without costing me a fortune thanks. I think the key to making trimming brass tolerable and efficient is to experiment with the nuances of technique each device requires.
My tool for trimming brass is the Lyman Universal Carbide Case Trimmer. Purchased from Brownells for around 90 bucks it has served me reasonably well and when I can get into a rhythm can be tolerably fast. Lyman describes the trimmer on their website as follows: “The Universal Carbide Case Trimmer features a premium Carbide Cutter Head with a fine grain and ultra-sharp cutting edge. The carbide head will hold its edge longer, making this trimmer ideal for volume reloaders. The popular patented Universal Chuckhead handles any case from .17 caliber to .458 caliber with no collets required. The Trimmer includes 9 of the most popular pilots.” It has served me well so far regardless of the previously mentioned universal challenges of brass trimmers. It is consistent when I’m consistent and as precise as I am. It has some very notables strengths and one glaring weakness. Knowing these particular nuances before purchasing and using the trimmer would have helped me tremendously and led to fewer frustrations while attempting to master its idiosyncrasies.
Let’s talk about the good. It’s a sturdy device and has a couple of holes in the frame so it can be mounted to your workspace. I personally prefer to clamp it to my workbench so I can place it and remove it at my leisure. The “Universal Chuckhead” is fantastic and allows for very quick engagement and disengagement of the piece of brass being trimmed while keeping it straight and true to the cutting bit. This greatly enhances the speed of which you can move from one piece of brass to the next as well as helping to insure consistency and precision. This is arguably the Lyman Universal Carbide Case Trimmer’s greatest attribute. The carbide cutting bits are sharp and easily trim the brass leaving a smooth cut with a minimum of rough edges or burrs.
Now the bad. The case trimmer has a very significant design flaw. One I learned about firsthand and later discovered was a known issue. Fortunately there is an easy solution but one I would have preferred learning about before it manifested itself in my trimmer. The picture below illustrates it best. The spindle or rod that connects to the cutter runs through a collar of sorts in the frame. With repeated use the carbide bit when pulled from the case mouth will often times impact the collar with some force. You can see the collar has sunken somewhat within the frame in the picture on the left. Even more obvious is the collar protruding outside the frame on the right. There is a simple remedy and one you should immediately take if you decide to purchase this brass trimmer. Insert a washer between the rod and the carbide bit. The washer will impact the frame before the bit can impact the collar. It’s an easy and inexpensive fix. I just wish it wasn’t necessary.
So what’s the verdict? As I mentioned previously each trimmer has particular nuances that determine it’s speed and precision and the Lyman Universal Carbide Case Trimmer is no exception. Most notably is pressure. I strongly suspect that all case trimming techniques or devices suffer from this same challenge. The pressure you apply, either to the brass itself or the cutting device, impacts the depth of cut you ultimately make. When I apply a consistent and precise pressure I get consistent and precise results. The solution is simple: practice. I went through my fair share of brass that was cut either two short or needed a 2nd trim while getting a feel for the proper pressure. There are both tactile and audible cues to when the brass has been cut sufficiently. A little practice and it becomes easy enough. Keep in mind as well that I am talking about only a differences in the thousandths of an inch. For many purposes the difference between trimming a piece of .223 to 1.741 and 1.750 in entirely inconsequential. The video below shows the Lyman Universal Carbide Case Trimmer in action. It’s as accurate as I want it to be and fast enough to get a couple hundred rounds done an hour.