CCW Guns, Concealed Carry Firearms
Springfield Hellcat vs Sig P365: Size, Capacity and Weight Compared
Quick answer: On the makers’ own spec sheets, the Springfield Hellcat and the Sig P365 are nearly the same size. Springfield lists the Hellcat 3″ OSP at 4 inches tall with the flush magazine and 6 inches long. Sig lists the P365 at 4.3 inches tall and 5.8 inches long. The clearest difference is capacity: the Hellcat ships with an 11-round flush magazine and a 13-round extended one, and the P365 ships with two 10-round magazines. Weight is close on paper (17.9 ounces for the Hellcat with the flush magazine, 17.8 for the P365), but the two makers don’t measure it the same way.
Hellcat vs P365 Specs, Side by Side
| Spec | Springfield Hellcat 3″ OSP | Sig P365 |
|---|---|---|
| Height | 4 in with the flush magazine; 4.5 in with the extended magazine | 4.3 in |
| Width, as the maker lists it | 1 in grip width | 1.1 in overall width |
| Overall length | 6 in | 5.8 in |
| Barrel length | 3 in | 3.1 in |
| Weight, as the maker lists it | 17.9 oz with the flush magazine; 18.3 oz with the extended magazine | 17.8 oz (Sig doesn’t say whether that includes a magazine) |
| Magazines in the box | One 11-round and one 13-round extended | Two 10-round |
| Sights | Tritium/luminescent front, U-notch rear | XRAY3 day/night sights |
| Optic ready | Yes: rear slide deck cut for a micro red dot | Yes (Shield RMSc footprint) |
| Maker’s size class | Micro-Compact | Micro-Compact |
Sources: Springfield Armory’s product page for the Hellcat 3″ Micro-Compact OSP 9mm (HC9319BOSP) and Sig Sauer’s product page for the P365 (365-9-BXR3P), both checked October 29, 2026. Springfield lists grip width and Sig lists overall width, so the width row is not a like-for-like comparison. Sig lists inches to one decimal place.
Which Hellcat and Which P365?
Both makers sell several versions. This page compares the base 9mm models:
- Hellcat 3″ Micro-Compact OSP (HC9319BOSP): Springfield’s current base Hellcat. “OSP” means the slide is cut for a micro red dot. Springfield also sells the Hellcat Pro and the Hellcat RDP.
- P365 (365-9-BXR3P): Sig’s optic-ready base P365. Sig also sells the taller P365X and the larger P365-XMACRO, which our Sig P365 vs P365X comparison covers.
Grip Height: Close, and It Depends on the Magazine
The grip is the part that prints. When you bend, reach or sit, the bottom of the grip is what pushes out against your shirt.
With its flush 11-round magazine, Springfield lists the Hellcat at 4 inches tall, about 0.3 inches shorter than Sig’s 4.3 inches for the P365. With the 13-round extended magazine the Hellcat is 4.5 inches. Sig doesn’t say which magazine its 4.3-inch figure is measured with; the P365 ships with 10-round magazines.
Width and Length: What Sits Inside the Holster
Springfield lists a 1-inch grip width for the Hellcat. Sig lists 1.1 inches overall width for the P365. Those aren’t the same measurement, so the numbers don’t tell you which gun is wider. Inside the waistband, width adds to how far the gun and holster stand off your body.
Length is what sits below your belt. The Hellcat is 6 inches long and the P365 is 5.8 inches, so about 0.2 inches apart. The barrels are 3 inches and 3.1 inches.
Weight: Don’t Read Too Much Into a Tenth of an Ounce
Springfield lists the Hellcat at 17.9 ounces with the flush magazine and 18.3 ounces with the extended one. Sig lists the P365 at 17.8 ounces without saying whether a magazine is included. Because the makers don’t measure the same way, the 0.1-ounce gap doesn’t settle which one is lighter. If weight matters to you, hold each one with a loaded magazine before you buy.
Capacity: 11 or 13 vs 10
Springfield ships the Hellcat with one 11-round flush magazine and one 13-round extended magazine. Sig ships the P365 with two 10-round magazines and sells larger magazines separately. Out of the box, the Hellcat holds one more round with the flush magazine, and three more with the extended one.
Optics
Both base models are optic-ready. Springfield says the Hellcat OSP’s rear slide deck is cut to accept a micro red dot. Sig lists the P365’s optic footprint as Shield RMSc. If you add an optic or a light, you’ll need a holster made for that gun with that setup.
Making Either One Comfortable to Carry
Whichever you choose, the grip needs to tuck in to stop printing. Three things do most of the work:
- A claw or wing on the holster presses against your belt and rotates the grip in toward your body.
- A wedge low on the body side of the holster pushes the muzzle end out, which tips the grip in. For printing, keep the fill fuller and mount it low. For comfort, start in the middle on fill and move it toward the edge that digs in. Our wedge placement guide shows where it goes.
- A stiff gun belt keeps the holster from sagging. We carry Kore ratcheting gun belts.
We make the Cloudster Pillow, a soft holster wedge made of adjustable cooling-gel memory foam in a fabric cover. It attaches to the back of your holster with hook-and-loop Velcro and goes on any holster: Kydex, leather or hybrid. On leather or hybrid holsters, some owners make it semi-permanent with a dot of glue at the corners and center of the adhesive Velcro, or by lightly sanding the mounting spot with very fine-grit sandpaper. Both change your holster, so check its warranty first.
Which size? Both guns take the Standard or the Deluxe with no light. Step up to the Deluxe or the Monster for a weapon light or a sidecar mag carrier. For larger body frames we recommend sizing up: a larger pillow can always be made to feel smaller by taking some fill out, but a smaller pillow can’t be made to feel bigger.
Our size finder takes 30 seconds, or tell us your gun and holster and we’ll confirm. For holster setup, see our Sig P365 holster guide and Hellcat Pro holster guide.
Hellcat or P365: How to Decide
Choose the Hellcat if:
- You want more rounds out of the box: 11 flush and 13 extended, against 10
- You want the shorter grip with the flush magazine: 4 inches against 4.3
Choose the P365 if:
- You want the shorter gun overall: 5.8 inches against 6
- You want an optic footprint the maker names: Sig lists Shield RMSc
- You may move up to a P365X or XMACRO later; see our P365 vs P365X comparison
Comparing other slim 9mms? See our Shield Plus vs P365, Glock 43X vs Sig P365 and Glock 43 vs 43X comparisons, or our best carry pistols guide.
Quick Answers
Is the Hellcat smaller than the P365?
Shorter in grip height with the flush magazine (4 vs 4.3 inches) and 0.2 inches longer (6 vs 5.8 inches). The makers list width differently: 1-inch grip width for the Hellcat, 1.1 inches overall for the P365.
Which holds more rounds?
The Hellcat. Springfield ships it with an 11-round and a 13-round magazine. Sig ships the P365 with two 10-round magazines.
Which one is lighter?
The makers’ figures can’t settle it. Springfield lists 17.9 ounces with the flush magazine; Sig lists 17.8 ounces without saying whether a magazine is included.
Are both optic-ready?
Yes. The Hellcat OSP’s slide is cut for a micro red dot, and Sig lists the P365’s footprint as Shield RMSc.
What size Cloudster Pillow do I need?
The Standard or the Deluxe for a Hellcat or P365 with no light. Step up to the Deluxe or the Monster for a weapon light or a sidecar mag carrier. For larger body frames we recommend sizing up.
Written by the Cloudster Pillow team. We make holster wedges and carry Kore gun belts. We don’t sell firearms or holsters, and nobody paid for this comparison. Specs are from Springfield Armory’s and Sig Sauer’s published product pages, checked October 29, 2026. This isn’t legal advice: magazine limits and carry laws vary by state.
