NEW Dies from Area 419: M-Series Sizer (In-Depth)

Brand new dies from AREA 419 and something never seen before! Learn more about them below! 


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All New Dies 

Craig Arnzen from Area 419 came out to the Ultimate Reloader Ranch to give us the details on their new ZERO dies. We’ve previously covered the Area 419 ZERO press among other products, but this is the company’s first leap into die creation. 

Craig explained Area 419’s ZERO reloading pursuit comes from their goal to have a press with ZERO run-out, ZERO play, etc. to create ammunition with ZERO variability. They recognize that true zero is impossible in these areas, but they are determined to continue chasing it. As they tested the ZERO press, Craig noticed that they were doing as much die testing as they were press testing. They began to look at the variables they observed in dies and what could be done to eliminate them. 

Over the next few years, they continued investigation, but also began to learn of problems and grievances customers called in with. This list of recurring problems turned into the foundation of ZERO dies. ZERO dies address the following: simplify headspace and enhance consistency, simplify setting neck tension, achieve true on-spec sizing and have greater adaptability. 

Setting out to fix existing problems runs the risk of creating new ones or complicating the manufacturing process. Area 419 has built a die they believe is the most well-featured, easy to use, and most complete die ever made.

Headspacing and Sizing 

Area 419 already has a shellholder kit with different shims for different sizing options, but the ZERO die has a different approach with more control. Craig explained that when sizing, he likes to see the top of the shellholder meet the bottom of the die. This gives a very consistent chamber size. On a standard ⅞” die, the modular shellholder system allows you to control where that “bolt face” is on the bottom.

The ZERO die allows you to move the chamber against a fixed point. This allows for a micrometer-headspace adjustment in sizing. Instead of cutting out dies, having them float in space, or swapping out dies, you can adjust the headspace with a micrometer, much like you can with many seating dies.

Dimensional correctness is another issue addressed with ZERO dies. After you reload brass several times, it’s common to get some stick at the top of the primary extraction. This generally derives from inappropriately resized brass. This happens because most sizing dies are the same size or a bit larger than your chamber, especially if you are shooting a factory chamber or a slightly oversized chamber, which is relatively common. This means that when you shoot, your brass is fireformed to too large a spec and you need to size it down. If your sizing die doesn’t allow you to size the brass down, after just a few reloads, you’ll begin to get some interference between the web and chamber mouth. The ZERO die sizes down to a true factory spec on brass to allow for nice, clean extraction without a sticky bolt. This is helpful to the shooter so he/she doesn’t have to break position. 

Craig says there is no excuse for a sticky bolt, and the issue usually comes down to inappropriately sized chambers in sizing dies. 

The third part of this equation is neck tension. Craig has always believed neck sizing should be done from the inside of the neck and be the last step. Many people will use a mandrel die to do this. Other dies have a pull-through expander, but if you aren’t fully supporting the neck from the inside, you aren’t getting an appropriate square size. The M-series ZERO sizer die has a precision-ground mandrel with a long bearing surface on each pull-through expander. This means that whether you are loading something with a shorter neck or longer neck in the same cartridge family, the bearing surface of the pull-through mandrel is sizing the entire neck at one time. 

All ZERO dies will come with a mandrel that will give you about 2 thousandths neck tension, but others will be available. 

About the Area 419 M-Series Sizer Die

These dies are all cut with reamers to avoid the inconsistencies found with boring dies. Besides correct internal dimensions and a hard stop with micrometer (M-series) adjustment, these dies have 1 ¼” threads. Craig explained they needed more room diametrically in order to include the features they wanted. Area 419 wanted a sizing chamber to have enough external support and space for it to be moved and managed inside the die. All of Area 419’s M-series sizing dies are 1 ¼” thread. The ZERO press ships with a ⅞” head and nine stations, but a hybrid head is also available with four ⅞” die stations and four 1 ¼” die stations as well as an 1 ¼” turret with eight 1 ¼” stations. 

Craig also noted that RCBS Rockchucker presses have a ⅞” thread, but if you pop out the black insert, you have an 1 ¼” press. In the future, the Area 419 S-series dies will be ⅞” with all the M-series features except the micrometer adjustment. 

Hydraulic Pressure

When sizing brass, you must use some kind of lubricant. These are all some version of a solid or liquid base. Liquids do not compress. When you are sizing and have the outside of the neck under pressure, you’re creating a sealed chamber with liquid between the shoulder and the sizing surface inside the die. Craig noted that every sizing sleeve has a relief hole for material to escape from. This contributes to greater consistency. This relief hole isn’t a new feature, but is commonly found in many resizing dies. A relief hole also helps prevent against hydraulic dents. 

Primer Flicker 

This feature is not new or unique to Area 419 dies, but something they decided to incorporate. The popularity of small primers in 308-based cartridges has soared. These small primers like to stick to the end of the decapping pin. The spent primer needs to go somewhere. The new Frankford Arsenal X10 has two stations for this reason. ZERO dies include some spring tension to throw the spent primer off the decapping pin.


Each die has several pieces. The sizing sleeve, the core of the system, is reamer cut nitrated 17-4 stainless. Nitriding helps with the movement of the sleeve inside the lower body, longevity, and provides lubricity against brass, which is actually very abrasive. The lower body, also of 17-4, is externally threaded 1 ¼” and fits around the sleeve. The precision-ground steel mandrel drops in with matching male and female tapers for square alignment while neck sizing. The upper body contains the stop that meets the micrometer for headspace and a small spring-loaded cap that pushes against the decapper at the top of the stroke. 

You can take your die apart to swap out an insert or clean it, but you generally won’t need to break it down this far. Craig does not recommend anyone taking apart the micrometer top, which goes on last. As a side note, the decapping pins are removable and each die comes with an extra, just in case. Tools for doing this are included as well. 

These dies must be used with an Area 419 shellholder, which you can order with your die, because of the larger rim needed to contact the rim. ZERO press shellholders are being offered first, with traditional click-in shellholders coming later. 

Testing the ZERO M-Series Die

We started with screwing the Area 419 shellholder onto the ZERO press. The die follows. Screw it in and run the ram up like a typical die. When the bottom touched, Craig made sure the micrometer was out fairly far while doing this before dropping in the lock ring to set the lower body. (It is possible to remove the upper body for cleaning without disturbing the lower body.) With the ram up, Craig ran down the micrometer until it stopped. With the sizing sleeve all the way down, brass will be oversized by 8 to 10 thousandths. Craig estimated coming out 4 thousandths from bottomed out. 

I pulled out some freshly annealed 6GT brass. I anneal every time before loading with the AMP annealer. I zeroed the comparator before resizing and found the guestimate setting came to -0.035. The micrometer made it very easy to make minute adjustments until I reached -0.02. This simplicity really shines when working with multiple chambers. I also appreciated that each stroke had very positive feedback— you could feel metal on metal.

Exploded View

There are 14 parts in each die, all with the purpose of making the best resizing die possible. The die starts with the micrometer head with graduations for each thousandth on top and various reference marks below. An O-ring inside sets the appropriate amount of tension. Further in is the upper body which connects to the lower body and houses two individual spring-driven parts, the primer flicker and sleeve stop. The nitrided mandrel, sizing sleeve and threaded decapping pin finishes the system out. 


While you won’t need to take your dies apart to this level, I wanted to walk through the construction of the ZERO M-Series sizing with Craig. While at $500 per die/shellholder combo, it is pricey, but offers something unique. The die itself is available for $450. 

Get the Gear! 

The Area 419 ZERO Press is available directly from Area 419 HERE (check page for current pricing!)

Pre-order the M-series die at!

Shellholders are available for ZERO owners now, with shellholders for other presses coming soon. Caliber pre-orders include 6mm Dasher, 6GT, 6 Creedmoor and 6.5 Creedmoor with 308 coming soon. Craig noted that Area 419 is catering to the short action PRS community first.

Also look for a special on hybrid heads! 

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Gavin Gear 

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