Worlds Finest trimmer
- By Pete Moore
- 1 Comments
- Last updated: 31/10/2019
There are many processes involved in case preparation, one of the most critical is trimming it to the recommended length. With modern bottlenecked types this is essential, as brass is ductile and the necks will stretch with firings. If they go too far, problems will arise; so, a trimmer is required to bring it back to factory specifications.
For years, I used a Lyman, which is like a mini, hand-operated lathe, it uses a universal chuck to hold the case head and a spud/pilot of the correct calibre to go inside the neck for stability. You adjust the cut length and turn the handle and it works. Over that time, I managed to loose most of the pilots and rang 1967SPUD Reloading Supplies about getting some new ones, but they did not have any in. However, I needed something quick, so they suggested an alternative in the form of the Little Crow World’s Finest Trimmer (WFT).
I agreed and what turned up was a bit different compared to the benchmounted machines. It consists of a round, aluminium body that mounts the cutter, which is a standard 3/8” diameter end mill. On the base is a rotary bearing that accepts the calibre adapters, as the Little Crow works on using the case shoulder as the datum point for trimming. It’s also intended to be used with a power tool, like an electric drill or lathe.
The Crow arrived along with 6.5x55 SE and a 243 Win adaptors (as ordered). I could see how it worked easily, the cutter is length-adjustable via two opposed 1/8” Allen grub screws and the insert pushes into the bearing in the base, where it’s held by an O-ring. All you need to do is hook it up to a drill, turn it on and insert the case; neck-first and gently push it in to start cutting.
The cutter was 3/8” diameter and would not fit my drill, I bought a replacement chuck from B&Q and that sorted it. I mentioned this to SPUD, and they said if I was not happy they’d give me a full refund, now that’s good service! I have plans to make a bench mounting rig for it to make the job easier. From here on in you make a master case, by measuring a fired one and adjusting the cutter until you have the correct COL and then Robert’s your father’s brother.
In use, you push the case in, which remains stationary as the tool revolves around it; hence the bearing. You can feel it cutting and also see the swarf coming out of the exit holes in the sides. When it’s finished, you can feel the difference, the end result is a smooth flat mouth that just needs chamfering to complete. In terms of accuracy, the overall deviation was 0.003-0.005” +/-, which is within limits. I found various makes of brass required fine tuning, as to COL adjustment, as I imagine they are all slightly different. I think it produces a more consistent and flatter cut than my Lyman too.