The FN 545 MRD is a striker-fired .45 ACP pistol with a 4.1-inch barrel and 15+1 capacity. The MRD designation indicates the optics-ready slide with driftable steel cowitness sights and a mounting cut compatible with the Holosun 407C red dot and similar optics. No manual safety — the striker-fired single-action-only mechanism handles safety through integrated systems. 
 

Key Specifications 

• Manufacturer: FN 
• Model: 545 MRD Holosun 
• Caliber: .45 ACP 
• Action: Striker Fired (SAO) 
• Capacity: 15+1 rounds 
• Barrel Length: 4.1 inches 
• Overall Length: 7.7 inches 
• Weight: 30 oz 
• Frame Material: Polymer Black Textured Grip 
• Sights: Driftable Steel Cowitness / Holosun 407C Red Dot Optic Option 
• Safety Features: No manual safety 
• Finish Color/Type: Black 
   

Detailed Features 

 
The polymer frame keeps weight at 30 oz despite the .45 ACP chambering. The textured grip provides consistent purchase during rapid fire. The trigger runs at approximately 6 lb pull weight — standard for striker-fired pistols at this class. Driftable steel sights cowitness with the included optic cut, so iron sight alignment is maintained as a backup when a red dot is mounted. The ambidextrous controls work for both left- and right-handed shooters without modification.

The FN 545 MRD draws a mix of enthusiastic and measured responses, which is fairly typical for a newer .45 ACP entry in a category dominated by established platforms.

Build quality and ergonomics come up positively in most hands-on reviews. FN's manufacturing standards are generally trusted, and the textured grip, optics-ready slide, and ambidextrous controls are all cited as well-executed features. The 15+1 capacity is a genuine advantage over older single-stack .45 ACP designs.

Recoil management is regularly praised. At 30 oz with a polymer frame, the gun handles .45 ACP recoil reasonably — multiple reviewers note it shoots flatter than expected for the caliber.

Accuracy gets solid marks. Out-of-box performance at range distances is consistently described as good, with groups running tight enough for both competitive and defensive use.

The trigger divides opinion. Some find it smooth and well-positioned; others want a lighter or shorter pull. This tends to come down to individual preference and what the shooter is used to.

Price and accessory availability are the two most common criticisms. As a newer model, holster options and aftermarket parts are more limited compared to platforms like the Glock 21 or SIG P220 in the same caliber. Price sits at the higher end of the full-size .45 ACP market, which some view as fair given FN's quality and others find harder to justify.