Lee vs RCBS for K31: Case Trimmer and Die Comparison
By Amis Thains Published 7 min read
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You are converting a surplus Swiss K31 to fire .308 Winchester and need to know which reloading gear will handle the long, thin case necks without causing feed jams or accuracy loss. This page breaks down the Lee versus RCBS choice for the press, the dies, and the case trimmer specific to the K31's unique dimensions.
In short: For most K31 owners, RCBS is the stronger choice because its carbide dies and robust press build handle the hard Swedish brass well and offer better accuracy potential.
Lee is the value pick if you want a complete, affordable setup and do not mind using single-stage tools that take more time per round.
You need a quality case trimmer from either brand to manage the K31's headspace, which is the critical factor in preventing your new rifle from going out of spec.
Quick picks
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Redding Premium Series dies offer the micrometer seating control needed for K31 precision.
Lee Pacesetter dies provide a complete, reliable package for the budget-minded loader.
The differences at a glance
When you are reloading for the K31, you are essentially loading .308 Winchester, but with a chamber that dictates tighter tolerances. The difference between Lee and RCBS comes down to die construction, press durability, and how they handle the specific brass you are using. If that sounds like your bench, read up on how coaxial presses work next.
| Factor | Lee Precision | RCBS |
|---|---|---|
| Press Build | Single-stage, cast iron, reliable | Single or turret, heavier cast iron, premium feel |
| Die Style | Carbide, smooth operation, less lube | Carbide or steel, high precision, requires lube |
| Case Trimmer | Air trimmer and manual options | Manual and air trimmers, robust |
| Best For | High volume, budget setups | Accuracy, turret setups, long-term durability |
Press build and durability for hard K31 brass
Swiss K31 brass is known for being hard. Over time, this brass can work-harden and become difficult to size back to spec if your press or dies are not up to the task. Both Lee and RCBS make cast iron presses that hold up well, but the feel and weight differ.
RCBS presses, like the Rock Chucker Supreme, have a heavier casting and a more rigid structure. This rigidity helps when you are sizing tight cases, as there is less flex in the frame.
The turret option on RCBS presses allows you to swap dies without adjusting the press, which is handy if you are switching between .308 for your K31 and another caliber.
Lee presses, such as the Challenger, are also cast iron and very sturdy. They are lighter and more compact. For a dedicated K31 setup, the weight difference matters less than the press’s ability to withstand the pressure of sizing hard brass. Both are strong enough, but RCBS wins on build quality and long-term stability.
Pro tip: If you plan to use a turret press, check that the dies are on the same thread size as the press body. RCBS and Lee dies are standard, but mixing brands on a turret can sometimes require adapters.
The heavier cast iron frame reduces flex when sizing hard Swedish brass.
- Each lever is designed for maximum ergonomic benefit with a specific press, please
- The bends of the Ergonomic Lever series keeps the lever travel distance the same, but
Die accuracy and seating control
Accuracy in a K31 depends on consistent case length and bullet seating depth. This is where die design matters most. RCBS and Lee both offer carbide die sets, but the control you have over the seating process varies. Before you buy anything, it is worth looking at comparing die retention methods.
RCBS die sets often come with micrometer heads on the seating die. This lets you set the seating depth in thousandths of an inch, which is critical for tuning your K31. Lee die sets usually use a simpler adjuster. It works well for reliable extraction and feeding, but it is not as precise for match-level accuracy.
For the K31, which is a military rifle with a chamber that can be slightly generous or tight, you want to start with the most precise tool you can afford. A micrometer seating die allows you to find the exact node where accuracy peaks. Lee is fine for volume, but RCBS wins on precision control.
Pro tip: Always check the bullet seating depth with a caliper or dial indicator. Do not rely on the die adjuster alone to ensure consistent groups.
Redding Premium Series dies give the micrometer control needed for K31 tuning.
- Those seeking to improve their handloading capabilities, will find everything in the
- The Carbide Expander Button reduces stress on the case neck; The Micrometer Adjusting
The case trimmer: The most critical tool for K31
Here is where many K31 owners get stuck. The K31 chamber is head-spaced for the original Swiss rim, which is about 0.006 inches thicker than standard .308 Winchester. When you reload with .308 cases, the headspace is larger than it should be.
This causes the case to stretch more at the neck and head. If you do not trim the cases back to spec, the necks will get too thick, and extraction will fail or the case will split.
You must use a case trimmer to bring the length back down. Lee makes the Loader trimmer, which is manual and air-powered. RCBS makes the X-2 trimmer, which is also air-powered and very smooth. Loaders in this spot often ask about reloading volume choice as well.
Both are effective. The air trimmer holds the case in place and rotates it against the cutter, so you do not have to twist the case by hand. This saves your wrist and gives a more consistent cut.
The difference is in the rigidity. The RCBS X-2 is generally considered stiffer, which can handle the hard K31 brass better. The Lee Loader is lighter and more affordable. If you are trimming a large volume of hard brass, the stiffer build of the RCBS trimmer will last longer and maintain tension better.
Safety first: Always set your trimmer to length just under your K31's chamber spec. If in doubt, measure your chamber with a gauge and aim for 1.470 to 1.472 inches for most .308 K31s, but check your specific rifle.
Speed, ease of use, and value
If you are loading for a family or a club, speed matters. Lee dies are carbide and do not need lube, which means you can run them faster and with less cleanup. This makes Lee the winner for high-volume, fast reloading sessions. The Challenger press is simple to set up and start using.
RCBS dies, even the carbide ones, often require a light lube. This adds a step. The turret press is faster for switching loads, but if you are only loading K31, a single-stage RCBS press is just as fast. The cost of RCBS is higher. You pay for the build quality, the micrometer heads, and the longer life of the tools.
For the K31 owner who wants the best accuracy and does not mind spending more, RCBS is the better buy. For the owner who wants to get in and out quickly, load cheap military surplus brass, and keep costs down, Lee is the value winner. The Lee Pacesetter set is a solid, no-nonsense option that gets the job done.
Lee Pacesetter provides a complete, affordable die set for budget K31 loaders.
- Convenient Carrying Case
- Perfect Die Set for a .308
Which should you buy?
- Buy RCBS if you want the most accurate K31 groups, plan to keep the rifle for decades, or want a turret press for multi-caliber use. The extra cost buys you better die control and a stiffer press.
- Buy Lee if you are on a budget, load high volumes of military brass, or want a setup that is quick to use with no lube required. The Pacesetter dies are the best entry point.
- Buy a quality case trimmer regardless. This is the non-negotiable tool. A stiffer trimmer like the RCBS X-2 will outlast a cheaper manual trimmer on hard K31 brass.
The bottom line
For the K31, RCBS is the better brand choice for accuracy and long-term durability, especially if you want micrometer seating control. Lee is the smarter buy for volume and budget. The most important tool is not the press, but the case trimmer. Get a stiff, air-powered trimmer to manage the headspace issue, and your K31 will stay reliable.
- Those seeking to improve their handloading capabilities, will find everything in the
- The Carbide Expander Button reduces stress on the case neck; The Micrometer Adjusting
Frequently asked questions
Can I use Lee dies on an RCBS press?
Yes. The press body is standard, so any single-stage die from either brand will screw in. However, if you are using a turret, you must make sure the die threads match the turret’s posts. RCBS and Lee both use standard die threads, but check the specific turret model’s manual to be safe.
Do K31 cases need to be trimmed every time?
Not every time, but more often than standard .308 cases. Because of the headspace issue, the cases stretch faster. Check your case length with a caliper after you shoot. If the length is over 1.480 inches, trim it back to 1.470 or 1.472 inches. Do not wait for the case to fail.
Is the RCBS Rebel a good press for K31?
The RCBS Rebel is a solid, budget-friendly single-stage press. It is strong enough for K31 reloading. It lacks the heavy casting of the Rock Chucker, but for most users, it will not limit your accuracy. It is a good middle-ground if you want RCBS dies but not the premium press cost.
What is the best case trimmer for K31 brass?
An air trimmer is the best choice. Manual trimmers are hard to keep consistent on hard brass. The RCBS X-2 or the Lee Loader are both excellent. The RCBS X-2 is stiffer and will last longer, but the Lee Loader is more affordable and works just as well for most people.