Smith & Wesson M&P15 Sport III
Smith & Wesson2024–presentContemporary
Also known as M&P15 Sport III, 13807
Image credit
- Title
- MP15
- Author
- danphamcdp(attribution required)
- Licence
- CC BY-SA 2.0
- Source
- https://commons.wikimedia.org/wiki/File:MP15.jpg
How Muzzle energy is calculated
E = ½ · m · v²
Inputs
- m4.018 g62.01 grverifiedsource62 gr as published, converted to grams.
- v916.1 m/s3,006 fpsestimatedInterpolated between sourced measurements at 368.3 mm and 508 mm.
1 of 2 inputs link to their source.
How Muzzle velocity is calculated
linear interpolation between the two nearest sourced barrel lengths
Inputs
- v at 368.3 mm905.3 m/s2,970 fpsverifiedsourceTable 2-1, muzzle velocity for the M4: 2,970 fps.
- v at 508 mm944.9 m/s3,100 fpsverifiedsourceTable 2-1, muzzle velocity for the M16A2: 3,100 fps. The M855 is the manual's service round for that rifle.
Assumptions
- Velocity is assumed to vary linearly between the two measurements. Over a short span that is a reasonable reading of the data; it is not a law.
2 of 2 inputs link to their source.
How Loaded mass is calculated
m_loaded = m_empty + m_magazine + n · m_cartridge
Not calculated: m_magazine has no sourced figure yet. Nothing is substituted for a missing input.
Assumptions
- One magazine, filled to the stated capacity. Spare magazines, optics, slings and lights are the owner’s, not the arm’s.
3 of 4 inputs link to their source.
How Free recoil is calculated
E_recoil = ½ · m_firearm · v_recoil²
Inputs
- m_firearm2.957 kg6.519 lbverifiedsource6.52 lb (2957 g) as published.
- v_recoil1.245 m/s4.084 fpsestimated
Assumptions
- Propellant gas momentum is excluded: ARMAG does not record charge weights (SPEC.md §14). This is therefore a lower bound on the real free recoil, consistent between entries but smaller than a figure that includes the gas term.
- Free recoil: the arm is unrestrained. Stock design, muzzle devices, stance and shooter mass are not modelled, because none of them is a property of the arm.
1 of 2 inputs link to their source.
How Capacity is calculated
as published for the primary chambering
Inputs
- capacity30verifiedsourceSupplied with one 30-round magazine.
1 of 1 inputs link to their source.
Derived figures
Computed from the sourced values above. Open ƒ on any figure for the formula, its inputs, and the assumptions it makes.
How Momentum is calculated
p = m · v
Inputs
- m4.018 g62.01 grverifiedsource62 gr as published, converted to grams.
- v916.1 m/s3,006 fpsestimatedInterpolated between sourced measurements at 368.3 mm and 508 mm.
1 of 2 inputs link to their source.
How Sectional density is calculated
SD = mass(gr) / (7000 · diameter(in)²)
Inputs
- mass4.018 g62.01 grverifiedsource62 gr as published, converted to grams.
- diameter5.7 mm0.2244 inestimatedsourceNo free NATO dimensional standard is published. The C.I.P. datasheet for the .223 Remington, which shares this bullet, gives a cartridge-maximum bullet diameter of 5.70 mm.
Assumptions
- Reported in the conventional lb/in² so it is directly comparable with published figures.
2 of 2 inputs link to their source.
How Power factor is calculated
PF = mass(gr) · velocity(fps) / 1000
Inputs
- mass4.018 g62.01 grverifiedsource62 gr as published, converted to grams.
- velocity916.1 m/s3,006 fpsestimatedInterpolated between sourced measurements at 368.3 mm and 508 mm.
Assumptions
- A competition classification defined by the IPSC and USPSA rulebooks, stated in their units. It describes a scoring category, not an effect.
1 of 2 inputs link to their source.
How Magazine dump is calculated
t = (n − 1) / (rpm / 60)
Not calculated: rpm has no sourced figure yet. Nothing is substituted for a missing input.
Assumptions
- Cyclic rate held for the whole magazine, no stoppages, trigger held down. A theoretical figure for comparing mechanisms, not a measured one.
1 of 2 inputs link to their source.
How Sight error at 1 mm is calculated
θ = atan(misalignment / sight radius)
Not calculated: sight radius has no sourced figure yet. Nothing is substituted for a missing input.
Assumptions
- Shows what a stated aiming error costs. The misalignment is the reader’s figure; the site does not claim how well anyone aims.
No input on this calculation carries a clickable source yet.
Specifications
Every row here is generated from the schema, so a figure recorded on this entry cannot be missing from the table — and the same rows, read the same way, are what the comparison shows.
Identity
- Type
- Rifle
- Action
- Self-loading
- Fire modes
- Semi-automatic
- Operating system
- Gas, direct impingement
- Designed in
- United States
- Produced in
- Introduced
- 2024
- Production
- 2024–present
Dimensions and mass
- Mass, empty
- 2.957 kg6.519 lbsource
6.52 lb (2957 g) as published.
- Magazine, empty
- not recorded
- Length
- 889 mm35.00 insource
Stock extended, 35 in (89 cm).
- Length, folded
- 812.8 mm32.00 insource
Stock collapsed, 32 in (81 cm). The stock telescopes; it does not fold.
- Width
- 63.5 mm2.500 insource
2.5 in (6.4 cm).
- Height
- 203.2 mm8.000 insource
Overall height, 8 in (20.3 cm).
- Barrel length
- 406.4 mm16.00 insource
16 in (40.6 cm).
Sights and rifling
- Sight radius
- not recorded
- Sight height over bore
- not recorded
- Rifling twist
- 203.2 mm8.000 insource
One turn in 8 in, five-groove 5R profile.
- Twist direction
- not recorded
- Grooves
- not recorded
- Sight graduation
- not recorded
Operation
- Cyclic rate
- not recorded
- Trigger pull
- not recorded
- Effective range
- not recorded
- Units produced
- not recorded
- Launch price
- USD 799 · 2026 · US
Chamberings
- 5.56x45mm NATOprimary30 rounds
- .223 Remington30 rounds
Scale
A to-scale outline against family siblings. The dimensions are sourced; the shape is a representative outline for the type, and says so.
- Smith & Wesson M&P15 Sport III889 mm35.00 in
- Colt M4 Carbine838.2 mm33.00 inheight not recorded
- La France M16K673.1 mm26.50 inheight not recorded
- M16 rifle1,007 mm39.63 inheight not recorded
Representative outline — the dimensions are sourced, the shape is not. Overall length, and barrel length where recorded, are drawn from this entry's own figures; the profile is a generic one for the firearm type and says nothing about this arm's actual contours. Colt M4 Carbine, La France M16K, M16 rifle record no height, so their outline is drawn at the type's proportion — that height is part of the shape, not a measurement.
Lineage
This design
- Clone of M16 rifle
Family
Detail
Smith & Wesson’s Sport line is the volume end of the AR-15 market: a rifle built to a price, sold on the strength of the standard it conforms to rather than on anything proprietary. The third generation arrived in 2024 with a free-floating handguard, a mid-length gas system and a one-in-eight barrel twist, which between them are the specification a buyer would previously have paid a gunsmith to assemble.
It is in the pilot batch to find out what a long-tail entry actually looks like, and the answer is instructive. The maker publishes a one-page specification sheet with eleven numbers on it and no photograph anyone else may reuse; there is no service manual, no independent measurement and no production figure. Even the price is a problem: the field on this site is for a launch price and what Smith & Wesson publishes is today’s price, so the year beside the figure is this year rather than 2024.
The image below is not this rifle. It shows the previous Sport II with parts its owner fitted, and it is here because it is the closest freely licensed photograph of the pattern that exists. Saying so is cheaper than pretending otherwise, and it is what the caption is for.
References
This entry's own bibliography. Every citation key on this page resolves into this list.
- M&P15 SPORT III specification sheet (SKU 13807) · Smith & Wesson Inc. · 2024 · read 2026-08-27
- M&P15 SPORT III product page · Smith & Wesson Inc. · read 2026-08-27
- Smith & Wesson M&P15 · 1362231933 · read 2026-08-27 · CC BY-SA 4.0
Last verified 2026-08-27 · review status: spot-checked