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 RMSx and ACRO P-2
AttributeShield SightsRMSxSpecs checked Jul 23, 2026AimpointACRO P-2Specs checked Jul 23, 2026
Typical priceNot documentedNot documented
Weight1.0 oz / 28.6 g excluding battery2.2 oz / 61 g
Overall dimensions1.61 × 1.34 × 1.07 in / 40.8 × 34 × 27.3 mm1.9 × 1.3 × 1.2 in / 47 × 33 × 31 mm
Product formatopticoptic
Mount / compatibilityShield RMS / RMSc footprintAimpoint ACRO interface
Catalog statuscurrentcurrent
BatteryUnderside CR2032CR2032
Battery life20,000-hour average in daylight50,000 hours at daylight setting 6
BrightnessAutomatic; lowest level is night-vision compatible4 night-vision and 6 daylight settings
Clear apertureNot documented0.59 × 0.59 in / 15 × 15 mm
DesignOpen emitterEnclosed emitter
Eye reliefUnlimitedUnlimited
HousingAluminumHigh-strength aluminum
LensGlassNot documented
Magnification
ParallaxNot documentedOperationally parallax-free
Reticle4 MOA, 8 MOA, or 65 MOA ring with 2 MOA dot2.5, 3.5, or 9 MOA red dot, depending on model
Water resistanceIP67: 3 ft / 1 m for 30 minutesSubmersible to 115 ft / 35 m
Editorial context

Choose by use case, not scoreboard.

RMSx: Full-size reflex optic.

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