Derraco Primer Gauge Set with 5 Gauges
Consistent primer seating depth is one of the most underrated factors in precision reloading. The Derraco Primer Gauge Set allows you to measure exactly how deep your primers are seated, determine primer pocket depth, and establish the optimal seating depth for your specific combination of brass and primers. This complete set includes five colour-coded gauge bodies covering the most common cartridge families.
Why Measure Primer Seating Depth?
Precision reloading is all about consistency. The primer initiates ignition, and variation in seating depth can cause differences in lock time and ignition pressure. This directly translates to higher ES and SD values. By measuring primer pocket depth before seating and checking the seated primer afterwards, you know exactly whether your primers are consistently at the correct depth.
The Derraco gauge works on a simple principle: calibrate the dial indicator to zero using the included calibration pin, then every measurement shows the deviation directly. Measure your empty primer pocket first, then the seated primer, and you'll know exactly how much crush you've applied. Most benchrest shooters aim for 0.002" to 0.004" below flush, but with this gauge you can determine what works best for your setup.
Complete Set for Multiple Calibres
Where other manufacturers require you to purchase a separate gauge for each calibre, Derraco includes five colour-coded bases. The colours make it easy to quickly grab the right gauge without searching. The bases fit all cases within the same cartridge family, so the .308 base also works for .243 Winchester, 6.5 Creedmoor, .260 Remington, and other cases sharing the same head diameter.
Build Quality and Materials
Derraco Engineering is known for their no-nonsense approach to precision tools. The gauge bodies are CNC-machined from 6061 aluminium and feature a wear-resistant hard-anodised coating. The calibration block pin is made from stainless steel and precision surface-ground for maximum accuracy. The contact point, or probe, is manufactured from tungsten carbide. This material is extremely hard and wear-resistant, ensuring the gauge remains accurate for years, even with intensive use.
Use Your Own Dial Indicator
The Derraco Primer Gauge is designed to work with standard dial indicators featuring an 8mm stem. Already have a quality indicator from Mitutoyo or another brand? Simply use that. The probe has an M2.5 thread and mounts easily. Note: the calibration pin and probe are essential for using this gauge.
Specifications
- Gauge body material: 6061 aluminium, CNC-machined
- Finish: Hard-anodised coating, colour-coded per calibre
- Calibration pin: Stainless steel, precision surface-ground
- Probe material: Tungsten carbide
- Probe thread: M2.5
- Dial indicator compatibility: 8mm stem diameter
- Included bases: .223 Remington, .308 Winchester, .300 Winchester Magnum, 7.62×39/PPC, .338 Lapua Magnum
- Compatible cartridge families: All calibres sharing the head diameter with the included bases
- Manufacturer: Derraco Engineering (Australia)
