Sig P365 Build Planner: Parts, Fit and Prices
Micro-compact 9mm on a serialized fire control unit. Mix grips and slides freely. 31 parts from 10 brands, each checked for fit against the rest of your build, with prices compared across retailers.
Open the Sig P365 BuilderStart from a Complete Build
Three Sig P365 builds where every part already fits, from $678.94. Open one in the builder and swap anything you like.
What's in the Budget Sig P365
- Fire Control Unit: Sig Sauer P365 Fire Control Unit $159.99
- Grip Module: Sig Sauer P365 Grip Module, Standard $49.99
- Slide Assembly: Sig Sauer P365 Slide Assembly, 3.1", Optic Ready $299.99
- Barrel: Sig Sauer P365 Barrel, 3.1" $109.99
- Recoil Spring: Sig Sauer P365 Recoil Spring Assembly $19.99
- Magazine: Sig Sauer P365 10-Round Magazine $38.99
What's in the Best Value Sig P365
- Fire Control Unit: Sig Sauer P365 Fire Control Unit $159.99
- Grip Module: Sig Sauer P365XL Grip Module $49.99
- Slide Assembly: Sig Sauer P365XL Slide Assembly, 3.7", Optic Ready $319.99
- Barrel: Sig Sauer P365XL Barrel, 3.7" $109.99
- Recoil Spring: Sig Sauer P365XL Recoil Spring Assembly $19.99
- Optic: Holosun HS507K X2 $274.99
- Magazine: Sig Sauer P365XL 12-Round Magazine $37.99
What's in the Premium Sig P365
- Fire Control Unit: Sig Sauer P365 Fire Control Unit, Flat Trigger $179.99
- Grip Module: Wilson Combat P365XL Grip Module $65.99
- Slide Assembly: Sig Sauer P365XL Spectre Comp Slide Assembly $449.99
- Barrel: Sig Sauer P365 Barrel, 3.1" $109.99
- Recoil Spring: Sig Sauer P365XL Recoil Spring Assembly $19.99
- Optic: Holosun EPS Carry $359.99
- Magazine: Sig Sauer P365XL 12-Round Magazine $37.99
Sig P365 Parts and Prices
Every Sig P365 part we list, cheapest first, with the lowest price we found (prices last checked Oct 5, 2026). The builder checks how each one fits with the rest of your parts.
Fire Control Unit
2 options, $159.99 to $179.99. The serialized chassis. Fits every P365 grip and slide.
Grip Module
3 options, $49.99 to $65.99. Standard (micro) or XL length.
| Sig Sauer P365 Grip Module, Standard Budget PickMicro length · 10 rd flush | $49.99 at Sig Sauer (sample price) |
|---|---|
| Sig Sauer P365XL Grip Module Best ValueXL length · 12 rd flush · Accessory rail | $49.99 at Sig Sauer (sample price) |
| Wilson Combat P365XL Grip Module Premium PickXL length · Aggressive texture · Flared magwell | $65.99 at OpticsPlanet (checked Oct 4, 2026) |
Slide Assembly
3 options, $299.99 to $449.99. Comes with sights and slide parts. 3.1" or 3.7".
| Sig Sauer P365 Slide Assembly, 3.1", Optic Ready Budget Pick3.1" · RMSc cut · X-Ray3 sights | $299.99 at Sig Sauer (sample price) |
|---|---|
| Sig Sauer P365XL Slide Assembly, 3.7", Optic Ready Best Value3.7" · RMSc cut · X-Ray3 sights | $319.99 at Sig Sauer (sample price) |
| Sig Sauer P365XL Spectre Comp Slide Assembly Premium PickXL length · Takes 3.1" barrel + XL spring · Integrated comp · RMSc cut | $449.99 at Sig Sauer (sample price) |
Barrel
5 options, $109.99 to $184.99. Must be the length the slide is made for.
| Sig Sauer P365 Barrel, 3.1" Budget Pick3.1" | $109.99 at Sig Sauer (sample price) |
|---|---|
| Sig Sauer P365XL Barrel, 3.7" Best Value3.7" | $109.99 at Sig Sauer (sample price) |
| Sig Sauer P365XL Barrel, 3.7", Threaded3.7" · Threaded 1/2x28 | $139.99 at Sig Sauer (sample price) |
| True Precision P365 Axiom Barrel, 3.1"3.1" · Match grade | $174.99 at OpticsPlanet (sample price) |
| True Precision P365XL Axiom Barrel3.7" · Match grade | $184.99 at OpticsPlanet (sample price) |
Recoil Spring
2 options, $19.99. Must match the slide length.
Optic
6 options, $189.99 to $389.99. Optic-ready P365 slides take the RMSc / Romeo Zero footprint.
| Sig Sauer RomeoZero Elite Budget PickRMSc footprint · Direct mount | $189.99 at OpticsPlanet (sample price) |
|---|---|
| Holosun HS407K X2RMSc footprint · 6 MOA dot | $229.99 at Primary Arms (sample price) |
| Holosun HS507K X2 Best ValueRMSc footprint · Multi-reticle | $274.99 at OpticsPlanet (sample price) |
| Shield RMSc 4 MOARMSc footprint · Very low profile | $289.99 at OpticsPlanet (sample price) |
| Holosun EPS Carry Premium PickRMSc footprint · Enclosed emitter | $359.99 at OpticsPlanet (sample price) |
| Trijicon RMRcc 3.25 MOARMRcc footprint | $389.99 at OpticsPlanet (sample price) |
Magazine
3 options, $37.99 to $42.99. Match the mag to the grip length for a flush fit.
| Sig Sauer P365XL 12-Round Magazine Best Value12 rd · XL grip flush | $37.99 at Primary Arms (sample price) |
|---|---|
| Sig Sauer P365 10-Round Magazine Budget Pick10 rd · Standard grip flush | $38.99 at MidwayUSA (sample price) |
| Sig Sauer P365 15-Round Extended Magazine Premium Pick15 rd · Extended | $42.99 at Primary Arms (sample price) |
Weapon Light
1 option, $145.00. Must fit the frame's accessory rail.
| Streamlight TLR-7 Sub, Sig P365/XL500 lm · P365 rail | $145.00 at Brownells (sample price) |
|---|
Holster
4 options, $64.99 to $74.99. Molded for one pistol size, with or without a light.
| Vedder LightTuck IWB, P365Kydex IWB · Optic cut · Open bottom | $64.99 at Brownells (sample price) |
|---|---|
| Vedder LightTuck IWB, P365XLKydex IWB · Optic cut · Open bottom | $64.99 at Brownells (sample price) |
| Vedder LightTuck IWB, P365 + TLR-7 SubKydex IWB · Carries TLR-7 Sub · Optic cut · Open bottom | $74.99 at Brownells (sample price) |
| Vedder LightTuck IWB, P365XL + TLR-7 SubKydex IWB · Carries TLR-7 Sub · Optic cut · Open bottom | $74.99 at Brownells (sample price) |
Case
2 options, $54.97 to $109.95. Any pistol case fits; check length if you run a light or comp.
| Savior Equipment Specialist Double Pistol Case, 14"Soft · Two pistols · Mag pouches | $54.97 at Brownells (sample price) |
|---|---|
| Pelican 1170 Protector CaseHard · Watertight · Lockable | $109.95 at OpticsPlanet (sample price) |