Independent field journal · Practice, evidence, judgmentIssue No. 01 / Summer 2026
KGKNOWN GROUNDClarity and capability in a contested world
Newsletter
Interactive research

Compare like with like.

Start with a product family, then choose two records. Differences, sources, and documentation gaps stay visible.

Step 1

Choose what you are comparing

Compare full-size and compact handgun-mounted optics.

Step 2

Select two pistol optics

Step 3

Review the differences

“Not documented” means Known Ground has not verified that field. It is not a zero, “none,” or compatibility claim.

Side-by-side comparison of 407C X3 and ACRO P-2
AttributeHolosun407C X3Specs checked Jul 23, 2026AimpointACRO P-2Specs checked Jul 23, 2026
Typical priceNot documentedNot documented
Weight1.55 oz2.2 oz / 61 g
Overall dimensions1.78 × 1.32 × 1.10 in1.9 × 1.3 × 1.2 in / 47 × 33 × 31 mm
Product formatopticoptic
Mount / compatibilityTrijicon RMR footprintAimpoint ACRO interface
Catalog statuscurrentcurrent
Adjustment1 MOA per clickNot documented
Adjustment range±50 MOANot documented
Automatic brightnessYesNot documented
BatterySide-loading CR1632CR2032
Battery life50,000 hours at setting 650,000 hours at daylight setting 6
Brightness8 daylight and 4 night-vision settings4 night-vision and 6 daylight settings
Clear apertureNot documented0.59 × 0.59 in / 15 × 15 mm
DesignOpen emitterEnclosed emitter
Eye reliefNot documentedUnlimited
Housing7075-T6 aluminumHigh-strength aluminum
Magnification
Motion activationShake AwakeNot documented
ParallaxNot documentedOperationally parallax-free
Reticle2 MOA red dot2.5, 3.5, or 9 MOA red dot, depending on model
SolarYesNot documented
Water resistanceIP67Submersible to 115 ft / 35 m
Window0.91 × 0.67 inNot documented
Editorial context

Choose by use case, not scoreboard.

407C X3: Current-generation open pistol sight with an RMR footprint.

ACRO P-2: Enclosed duty-focused reflex optic.