Sig Sauer P320 Full Size .45 ACP
Model: 320F-45-BSS
Sig Sauer P320 Full Size .45 ACP
Model: 320F-45-BSS
Full Specifications
About This Firearm
The Sig P320 Full Size in .45 ACP is a discontinued model. Sig stopped producing the .45 ACP variant and now only offers the P320 in 9mm. Used examples and remaining dealer stock still circulate, and magazines, grip modules, and parts remain available. The gun uses the same modular fire control unit as the 9mm P320, meaning the serialized trigger group can be swapped between grip sizes. At 29.5 oz with a polymer frame, it holds 10+1 rounds.
The 6.5 lb striker trigger is the heaviest in the .45 ACP category. The Smith & Wesson M&P 45 M2.0 pulls at 5.8 lbs, and the Glock G21 at 5.5 lbs. Reviewers describe the P320 .45's trigger as having a long take-up before a defined wall, with the break itself being clean but the overall pull weight working against speed. The gun includes SIGLITE night sights and ships with two magazines. The M1913 rail fits standard Picatinny lights. For buyers already invested in the P320 ecosystem with 9mm grip modules, the .45 variant is straightforward to adopt. For new buyers, the discontinued status means no future updates and eventually diminishing parts availability.
Best For
Strengths & Limitations
- The modular fire control unit swaps between grip sizes without tools, and the serialized chassis means the frame is not the registered part
- SIGLITE tritium night sights come factory-installed, which most striker-fired .45s in this group lack
- Discontinued by Sig Sauer. No further production runs, updates, or new variants will be made in .45 ACP. Long-term parts and magazine availability is uncertain.
- The 6.5 lb trigger pull is a full pound heavier than the Glock G21's 5.5 lbs and 0.7 lbs above the S&W M&P 45 M2.0's 5.8 lbs
- No optic cut on any .45 ACP P320 variant, while the competing Glock G21 Gen5 MOS ships with factory optic support
Category Rankings
How the Sig Sauer P320 Full Size .45 ACP ranks among full-size .45 ACP handguns.
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Calculate trajectory, drop, and energy for .45 ACP ammunition.
.45 ACP Ballistics →Where to Buy
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Frequently Asked Questions
Can I use P320 9mm grip modules on the .45 ACP version?
No. The P320 .45 ACP uses a different, wider fire control unit and grip module than the 9mm/.40/.357 SIG versions. The .45 ACP grip modules, magazines, and slide assemblies are not interchangeable with the smaller-caliber P320 parts. Only .45 ACP-specific P320 components work.
Is the Sig P320 .45 ACP still being manufactured?
No. Sig Sauer discontinued the P320 in .45 ACP. The current P320 lineup includes only 9mm models. Remaining dealer inventory is new-old-stock. Magazines and grip modules are still available from Sig and aftermarket suppliers, but production could end at any time.
What ammo does the P320 .45 ACP feed reliably?
Owners report the gun feeds standard 230gr ball ammunition and most hollow points without issues. Federal HST 230gr, Speer Gold Dot 230gr, and Hornady Critical Duty 220gr+P all have strong reliability records in the P320 .45. Some owners note that flat-nosed lead semi-wadcutters occasionally hang up on the feed ramp, but jacketed ammunition runs cleanly.