Sig Sauer P320 Holsters - Precision-Fit Solutions for Modular Platforms
Alien Gear holsters for the Sig Sauer P320 are engineered to match the exact slide length, grip module profile, and trigger guard geometry of each specific P320 variant. The P320's modular fire control unit (FCU) design allows users to swap grip modules, slides, and calibers, but holster fit depends on the precise external dimensions of your chosen configuration.
Each holster in this collection is molded for a specific P320 variant to ensure proper trigger guard coverage, consistent retention, and reliable draw mechanics.
This collection covers P320 Compact/Carry in .40 cal and 9mm, Subcompact in 9mm and .40 cal, Full Size in 9mm and .40 cal, M17, M18, XCarry (including configurations with Nightstick TCM-550XL and Streamlight TLR-7A), XCompact (including configuration with Foxtrot1X Light), XFive Legion, and P320-XTEN.
Light-bearing configurations are molded to specific weapon light models and will not accommodate different lights or mounting positions.
Sig Sauer P320 Technical Overview
The Sig Sauer P320 is a striker-fired, short-recoil-operated pistol built around a serialized fire control unit (FCU) that can be installed in different grip modules and slide assemblies. Key specifications vary by configuration but include:
P320 Compact/Carry
- Overall Length: 7.2 inches
- Height: 5.3 inches
- Barrel Length: 3.9 inches
- Width: 1.3 inches
- Capacity: 15+1 (9mm), 13+1 (.40 cal)
P320 Full Size
- Overall Length: 8.0 inches
- Height: 5.5 inches
- Barrel Length: 4.7 inches
- Width: 1.3 inches
- Capacity: 17+1 (9mm), 14+1 (.40 cal)
P320 M17/M18
- M17 mirrors Full Size dimensions; M18 mirrors Compact dimensions
- Both feature manual thumb safety and coyote tan finish
- Capacity: 17+1 (M17), 21+1 (extended); 17+1 (M18)
P320 X-Series (XCarry, XCompact, XFive Legion)
- Enhanced grip modules with improved texturing and undercuts
- Optics-ready slide cuts on most configurations
- XFive Legion: 5-inch barrel, competition-focused ergonomics
P320-XTEN
- Chambered in 10mm Auto
- Larger frame to accommodate higher chamber pressures
- Capacity: 15+1
The P320's striker-fired trigger system requires holsters with complete trigger guard coverage and no gaps that allow foreign objects to contact the trigger while holstered. Manual thumb safeties on M17/M18 models add a mechanical layer but do not replace the need for proper holster design and disciplined handling.
How to Choose the Right Alien Gear Holster for Your Sig P320
Match Your Exact P320 Configuration
Select holsters based on your specific slide length, grip module size, caliber, and accessory configuration.
The P320 Compact, Full Size, M17, M18, XCarry, XCompact, XFive Legion, and XTEN each have distinct external dimensions that affect holster fit. Do not assume that a holster for one P320 variant will fit another, even within the same general size class. Grip module profiles, trigger guard geometry, and slide contours vary across configurations.
Account for Weapon Lights and Optics
If you carry with a weapon-mounted light, choose a holster explicitly molded for your exact light model. This collection includes configurations for the Nightstick TCM-550XL, Streamlight TLR-7A, and Foxtrot1X Light.
Using a different light or mounting position may prevent the pistol from seating properly or may compromise retention. All P320 holsters in this collection accommodate optics-ready slides and red dot sights, but frame-mounted lasers or non-standard slide profiles may not be compatible.
Consider Manual Safety Compatibility (M17/M18)
The M17 and M18 variants feature manual thumb safeties that extend from the frame. Holsters designed for these models must provide clearance for the safety lever without interference during draw or reholstering.
Holsters molded for non-safety P320 variants may contact or block the safety, while M17/M18 holsters may have sweat guard cutouts that reduce trigger protection on non-safety frames. Always match your holster to your pistol's safety configuration.
Prioritize Carry Position Based on Role and Concealment Needs
Appendix and IWB holsters deliver deep concealment for everyday carry under fitted clothing, though slide length and grip module height influence printing and comfort.
Full-size P320 variants may print more in appendix carry compared to compact or subcompact configurations. OWB and paddle holsters provide faster access and greater comfort for range use, open carry, or duty applications but require longer cover garments for concealment.
Level II retention holsters suit law enforcement, security, and professional roles where weapon retention under physical contact is critical.
Verify Retention Adjustment and Trigger Guard Protection
Alien Gear holsters for the P320 include user-adjustable retention screws. Set retention to ensure the pistol locks securely with an audible click during holstering and releases smoothly during the draw.
Inspect the trigger guard area to confirm there are no gaps large enough to admit foreign objects like keys, seat belt buckles, or fabric. Poor trigger guard coverage has been identified as a specific safety concern with P320 holsters.
Carry Styles Supported by This Collection
Appendix
Appendix holsters position the P320 at the front of the waistband for fast access and effective concealment under fitted clothing.
Compact, XCarry, and XCompact configurations work well in this position, though Full Size variants may require careful cant and ride height adjustment to manage slide length and grip printing. Adjustable retention and breathable backers reduce hotspots during seated driving or extended wear.
Inside-the-Waistband (IWB)
Traditional IWB placement behind the hip (3–4 o'clock) balances concealment with comfort for many body types.
This position typically produces less printing when bending or seated compared to appendix carry, making it effective for users who prioritize all-day comfort over maximum concealment speed. Mid-ride holsters reduce grip protrusion while maintaining instinctive draw mechanics.
Outside-the-Waistband (OWB) Paddle
OWB paddle holsters deliver quick on-off convenience without threading through belt loops, making them practical for range use, training, or open carry. The paddle design allows flexible positioning along the belt line while maintaining stable retention. Full concealment requires jackets or longer cover garments, particularly with Full Size or XFive Legion configurations.
Belt
Belt-mounted OWB holsters provide a tighter ride against the body compared to paddle systems. This configuration suits range days, competitions, or open carry scenarios where accessibility and draw speed are prioritized over concealment. The secure attachment is stable during high-movement activities or when wearing gear.
Chest
Chest holsters distribute weight across the shoulders rather than the waistline, keeping the P320 accessible while wearing backpacks, plate carriers, or bulky outdoor gear. This carry method is effective for hikers, hunters, or field workers who need unobstructed waist access for tools or other equipment.
Drop Leg
Drop leg holsters position the P320 lower on the thigh for easier access when seated in vehicles or wearing tactical gear that blocks traditional belt carry. This configuration balances stability during movement with quick-draw capability, making it suitable for range training, duty scenarios, or environments where belt-mounted holsters are impractical.
Hook & Loop
Hook-and-loop mounting allows attachment to plate carriers, modular chest rigs, or specialized tactical gear. This carry method integrates the P320 into existing loadouts without requiring dedicated belt space, though it typically demands additional practice to develop consistent draw mechanics compared to rigid belt systems.
Belly Band
Belly band holsters provide concealment options for athletic wear, tucked shirts, or situations where traditional belts are impractical. The elastic design conforms to body movement while maintaining secure retention, though draw mechanics may require additional practice compared to rigid holster systems.
Level II Retention
Level II retention holsters feature active retention mechanisms—typically thumb-release or index-finger-release devices—that lock the pistol in the holster until deliberately disengaged.
These holsters are designed for law enforcement, security, and professional duty use where weapon retention during physical confrontation is critical. Draw mechanics require specific training to ensure smooth, consistent access under stress.
Common Fit or Selection Mistakes to Avoid
Assuming All P320 Holsters Fit All P320 Variants
The P320's modular design allows significant configuration changes, but holster fit depends on external dimensions. A holster molded for the P320 Compact will not properly fit the Full Size, XCarry, or XTEN due to differences in slide length, grip module height, and trigger guard profile.
Similarly, holsters for standard P320 frames may not accommodate X-Series grip modules, which feature tighter, less-flared trigger guard profiles. Always select holsters explicitly molded for your exact variant.
Using Non-Matching Weapon Lights
Light-bearing holsters are molded to specific weapon light models and mounting positions. A holster designed for the Streamlight TLR-7A will not accommodate the Nightstick TCM-550XL or Foxtrot1X Light, and vice versa.
Even small differences in light body shape, switch placement, or rail mounting footprint can prevent the pistol from seating correctly or compromise retention. Verify exact light compatibility before purchase.
Mixing M17/M18 Safeties with Non-Safety Holsters
M17 and M18 holsters include clearance cutouts for the manual thumb safety lever. Using these holsters with non-safety P320 variants may reduce trigger guard protection due to the safety cutout.
Conversely, using non-safety holsters with M17/M18 pistols may cause the safety lever to contact the holster body, interfering with draw or reholstering. Match your holster to your pistol's safety configuration.
Attempting to Adapt Holsters for Heavily Modified P320s
Aftermarket slides with non-standard profiles, barrel-mounted compensators, custom grip modules with altered trigger guards, or unusual light/optic combinations may not fit holsters molded for OEM P320 configurations.
If you have significantly modified your P320 beyond factory specifications, verify compatibility or expect fitment issues.
Neglecting Trigger Guard Gap Inspection
The P320's striker-fired trigger system is vulnerable to unintended discharge if foreign objects enter the trigger guard while the pistol is holstered.
Inspect holsters to ensure there are no gaps large enough to admit keys, fabric, seat belt buckles, or other items. Holsters with poor trigger guard coverage or excessive clearance around the trigger area introduce significant safety risk.
