FW Arms’ .223 dies were central to the success of our mega brass processing project with Mojo Precision and Mark 7. This time, we’re testing FW Arms’ 9mm hybrid sizing die with dynamic spring hold down!
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Set-Up and Demo
The first order of business was changing the progressive X-10 from .308 to 9mm.
This process takes some time, starting with removing the dies, then the powder measure. (I decided to leave the powder measure off since I am just processing cases.)
I swapped out the priming system, shellplate, swaging pin, priming pin, case feed parts, and case feed bowl. I also changed all of the locator buttons around the base of the press.
When the press was fully set for 9mm, station one held the case feed while station two stayed empty.
Station three held the FW Arms sizer/decapper and station four held the FW Arms dynamic hold down die (micro version) for swaging. The rest of the stations stayed empty.

Prior to filling the case feed bowl, I lubed the once-fired 9mm cases from Mojo Precision with Hornady One-Shot. FW Arms’ 9mm sizing die is carbide, but FW Arms still recommends using lube for smoother operation. I was able to process the cases incredibly quickly with no hiccups.
About the FW Arms’ 9mm Full-Length Hybrid Sizing Die
FW Arms’ 9mm full-length hybrid sizing die features a DLC (diamond-like coating) for reduced friction and a retained carbide ring.
Its design also eliminates the “coke bottle” effect.
From FW Arms:
-
- Long lasting carbide
- Tool steel nose
- Hybrid profile for great neck tension and drastically reduced “bottle” profile on your ammo
Who’s going to pay $190 for a carbide sizing die??? NOT US!!!
After 44 weeks of development we finally came to a grind profile that we like.
The F.W. Arms™ Carbide Hybrid Profile Sizing Die is a full length 9mm sizing die that will give you the best of both worlds: Great Neck Tension and almost no “bottle” profile.
Our carbide sizing ring is positively held into place with our tool steel nose. Each die will be outfitted with a popper style decapper and have the ability to add-on our Dynamic hold down assembly so you can size over swage if you like.
Full disclosure, the steel die pieces are U.S.A. made, as they are machined right here in Las Vegas with our in house CNC machines. The carbide is an import at the moment, we are actively looking for a US source for all of these that won’t break the bank, ours or yours.
The dynamic spring hold down add-on combines swaging and sizing to free up a press station for another purpose like crimping.
Changing FW Arms’ Sizing Die to a Hold Down Die
I utilized FW Arms’ dynamic spring hold down add-on to their full-length sizing die to swage and size simultaneously. The FW Arms’ 9mm sizing die comes with two decapping rods: one standard size and one smaller diameter.
I removed the die cap and spring to expose the installed decapping rod, and removed it.
Changing die setups required making press adjustments. Stations one and two remained the same, but I swapped the sizer/decapper in station three for a simple decapping die.
I secured the sizing die body in station four, screwing in the die until it touched the shell plate with the ram raised, then backed it off about ⅛ of a turn.
Next came installing the hold down. I placed the zero-position spacer in the swaging station and lowered the die over top. From this position, I added the nut and spacer included with the hold-down add on before screwing on the hold-down itself.

Taking extra care with the fine threads, I screwed the hold down add-on down until I felt stiff resistance against the zero spacer, then tightened the die nut. Raising the ram and removing the spacer was the final step. This “reverse” setup ran just as smoothly as the original!
Conclusion
Simultaneous swaging and sizing is a new concept for me, but I like it. As always, I was impressed with the quality and practicality of FW Arms’ dies.
While I wasn’t short on stations with the X-10, combining an operation to free up a station can come in handy!
Get the Gear
FW Arms – Use Code UR10 for 10% Off Your Entire Purchase!
(Expect the FW Arms 9mm Carbide Hybrid Sizer to be in stock by March 2025!)
Mojo Precision – Use Code UR10 to Save 10% on All Casings
Hornady One-Shot Case Lube at Midsouth Shooters Supply and Creedmoor Sports
Frankford Arsenal X-10 (Also available from Midsouth Shooters Supply)
Frankford Arsenal Die Locker Lock Rings (Also available from Midsouth Shooters Supply)
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Thanks,
Kyle Shields