How long is a G3 rifle? The standard Heckler & Koch G3A3 measures about 1,023 mm (40.3 inches) from muzzle to buttplate.
This guide covers G3 rifle dimensions for every major variant, plus barrel, weight, magazine and sight sizes.
You’ll also see how G3 rifle size compares with other battle rifles and what it means for US owners.
Quick Conversion
| Measurement | Heckler & Koch G3 Rifle |
|---|---|
| Length (Millimeters) | 1,023 mm |
| Length (Centimeters) | 102.3 cm |
| Length (Meters) | 1.023 m |
| Length (Inches) | 40.28 in |
| Length (Feet) | 3.36 ft |
| Length (Yards) | 1.12 yd |
| Weight (Kilograms) | 4.5 kg (about, empty) |
| Weight (Grams) | 4,500 g |
| Weight (Milligrams) | 4,500,000 mg |
| Weight (Ounces) | 158.7 oz |
| Weight (Pounds) | 9.92 lb |
Quick tip: Weight is about 4.5 kg unloaded, so it varies by variant and configuration. Divide millimeters by 25.4 for inches, or multiply kilograms by 2.2046 for pounds.
Quick Reference List: 21 Measurements Covered
21 Heckler & Koch G3 Lengths, Weights and Size References
Here’s every G3 length, weight and size reference in this guide, grouped by category for fast scanning.
| # | Item |
|---|---|
| Length by Variant | |
| Heckler & Koch G3A3 length (fixed stock) | |
| Heckler & Koch G3A4 length (stock extended) | |
| Heckler & Koch G3A4 length (stock collapsed) | |
| Heckler & Koch G3KA4 carbine length | |
| Heckler & Koch HK91 civilian rifle length | |
| Barrel | |
| Standard G3 barrel length | |
| G3KA4 short barrel length | |
| Barrel vs. total length | |
| Weight | |
| G3A3 empty weight | |
| Loaded G3 weight with a 20-round magazine | |
| G3A4 and G3KA4 weight and handling | |
| Magazine, Sights & Accessories | |
| 20-round magazine size | |
| Rear diopter sight and sight radius | |
| Bayonet and bipod | |
| Scope mount and optic | |
| Size Comparisons | |
| G3 vs. FN FAL | |
| G3 vs. M14 (Springfield Armory M1A) | |
| G3 vs. AR-15 and M4 | |
| US Owner Considerations | |
| Storage and gun case sizing | |
| Legal minimum lengths | |
| Fit and length of pull | |
G3 Rifle Length by Variant
Each model has its own stock and barrel, so start with the exact G3 you own or plan to buy.
Heckler & Koch G3A3 Length (Fixed Stock)
The Heckler & Koch G3A3 measures about 1,023 mm (40.3 in) overall, which answers how long is a G3 rifle for most people. Some spec sheets round it to 1,024 or 1,025 mm.
That makes the G3A3 a little longer than a yardstick plus four inches. Its fixed polymer buttstock never changes that G3 rifle length.
Heckler & Koch G3A4 Length With Stock Extended
With its stock fully out, the Heckler & Koch G3A4 measures about 1,020 mm (40.2 in). That is almost the same as the fixed-stock G3A3.
The sliding metal buttstock and rubber buttplate give the G3A4 the same full-size reach as the older design.
Heckler & Koch G3A4 Length With Stock Collapsed
Push the Heckler & Koch G3A4 stock in, and overall length drops to about 840 mm (33.1 in). That saves roughly 180 mm (7.1 in).
A collapsed G3A4 is close to the length of a typical 33-inch baseball bat. That shorter shape suits tight spaces and smaller cases.
Heckler & Koch G3KA4 Carbine Length
The Heckler & Koch G3KA4 carbine measures about 895 mm (35.2 in) with the stock extended. Collapsed, it shrinks to about 711 mm (28.0 in).
At full stretch, the G3KA4 is roughly 128 mm (5.0 in) shorter than the G3A3. It is the smallest factory G3 rifle size in the family.
Heckler & Koch HK91 Civilian Rifle Length
The Heckler & Koch HK91 is the semi-automatic civilian version of the G3 sold in the USA. Parts makers list its overall length at about 40.5 in (1,029 mm).
The HK91 shares the G3’s 17.7-inch barrel and fixed stock layout. So the HK91 sits just a hair longer than the military G3A3.
G3 Barrel Length and Overall G3 Rifle Size
Barrel length is the biggest single reason one G3 is longer than another.
Standard G3 Barrel Length
The standard Heckler & Koch G3 barrel is 450 mm (17.7 in) long and hammer-forged. Most reference sheets agree on that figure.
That is shorter than the barrels on full-size rivals like the FN FAL and M14. The Heckler & Koch G3 stays compact for a 7.62×51mm NATO rifle.
Heckler & Koch G3KA4 Short Barrel Length
The Heckler & Koch G3KA4 carries a 315 mm (12.4 in) barrel. That is 135 mm (5.3 in) shorter than the standard G3 barrel.
This shorter barrel is why the G3KA4 is the smallest G3 ever fielded. It also gives the G3KA4 more muzzle blast than the full-length rifle.
Barrel Length vs. Total G3 Rifle Length
On the Heckler & Koch G3A3, the barrel makes up about 44% of the 1,023 mm total. On the G3KA4 with its stock out, that share falls to about 35%.
With the G3KA4 stock collapsed, the barrel share climbs back to about 44%. So G3 rifle length depends as much on the stock as on the barrel.
G3 Rifle Weight and Balance
Weight changes how a rifle feels in your hands, so it belongs right beside length.
Heckler & Koch G3A3 Empty Weight
The Heckler & Koch G3A3 weighs about 4.4 kg (9.7 lb) empty on most spec sheets. Small Arms Survey lists 4.58 kg (10.1 lb), so expect a small spread.
Picture carrying a 12-pack of canned soda, which is about 4.5 kg. That is the rough feel of an empty Heckler & Koch G3A3.
Loaded Heckler & Koch G3A3 Weight With a 20-Round Magazine
An empty G3 20-round magazine weighs about 280 g (9.9 oz). Add 20 cartridges of 7.62×51mm NATO at roughly 25 g each, and the magazine alone reaches about 0.8 kg (1.7 lb).
That puts a loaded Heckler & Koch G3A3 near 5.2 kg (11.4 lb). Treat that as an estimate, since cartridge and magazine weights vary.
Heckler & Koch G3A4 and G3KA4 Weight and Handling
The Heckler & Koch G3A4 weighs about 4.7 kg (10.4 lb), while the G3KA4 comes in near 4.1 kg (9.0 lb). The metal stock adds weight to the G3A4, and the short barrel trims it on the G3KA4.
On any Heckler & Koch G3, the stamped steel receiver and forward cocking handle shape the balance. A longer rifle puts more weight out front.
G3 Rifle Dimensions: Magazine, Sights and Accessories
Add-ons change the practical size of a G3, so measure them separately.
Heckler & Koch G3 20-Round Magazine Size
The standard Heckler & Koch G3 20-round magazine weighs about 280 g (9.9 oz) empty and feeds 7.62×51mm NATO. Longer 30-round and 50-round drum versions also exist.
With the 20-round magazine inserted, the Heckler & Koch G3 stands about 220 mm (8.7 in) tall. That is a bit taller than the short edge of a US letter sheet.
Heckler & Koch G3 Rear Diopter Sight and Sight Radius
The Heckler & Koch G3 rear diopter sight uses a rotating drum marked from 100 to 400 m in 100 m steps. You turn it to match your target distance.
The Heckler & Koch G3 sight radius measures about 572 mm (22.5 in). That long baseline between front and rear sights helps precise aiming.
Heckler & Koch G3 Bayonet and Bipod
A bayonet fits the muzzle end of the Heckler & Koch G3, and long-barreled versions can launch rifle grenades from the barrel. A detachable bipod is optional.
A mounted bayonet adds G3 rifle length at the muzzle, so measure with it attached for a precise fit. A folded bipod barely changes the footprint.
Heckler & Koch G3 Scope Mount and Optic
The receiver of the Heckler & Koch G3 has recesses for claw-type clamp mounts. That lets owners attach optics without drilling.
A mounted scope adds height to the Heckler & Koch G3. The G3SG/1 variant weighs about 5.54 kg (12.2 lb) with its optic, and the 220 mm height figure excludes scope and mount.
G3 Rifle Size Compared With Other Rifles
Comparisons help American readers picture the G3 next to rifles they already know.
Heckler & Koch G3A3 vs. FN Herstal FN FAL
The FN Herstal FN FAL runs about 1,090 mm (42.9 in) in standard form. The Heckler & Koch G3A3 stops at 1,023 mm (40.3 in).
So the Heckler & Koch G3A3 is roughly 2.6 inches shorter than the FN FAL. Guns & Ammo also notes the G3 is shorter than other NATO battle rifles.
Heckler & Koch G3A3 vs. Springfield Armory M1A
The standard Springfield Armory M1A, the civilian M14 type, measures about 44.3 in (1,125 mm). The Heckler & Koch G3A3 measures 40.3 in.
Next to the Springfield Armory M1A, the G3A3 is about 4 inches shorter overall. That gap matters in tight cabins and cases.
Heckler & Koch G3A3 vs. Colt M4 Carbine
The Colt M4 carbine measures about 29.8 in (757 mm) collapsed and 33.0 in (838 mm) extended. It weighs near 6.4 lb (2.9 kg) unloaded.
A Heckler & Koch G3A3 at 40.3 in is more than 7 inches longer than a fully extended Colt M4. It is also much heavier.
G3 Rifle Size Considerations for US Owners
Practical and legal size questions matter most to American buyers and collectors.
Heckler & Koch G3A3 Storage and Gun Case Sizing
A Heckler & Koch G3A3 needs a case with at least 44 inches of interior length to clear its 40.3 in body plus padding. Plano makes hard rifle cases in several lengths, so check the interior number.
A collapsed Heckler & Koch G3A4 at 33.1 in fits a much shorter case. A collapsed G3KA4 at 28.0 in fits smaller bags still.
Heckler & Koch G3 Legal Minimum Lengths in the USA
Under US federal law, a rifle needs a barrel of at least 16 inches and an overall length of at least 26 inches. The Heckler & Koch G3A3 and the civilian HK91 clear both, with 17.7 in barrels.
The Heckler & Koch G3KA4 has a 12.4 in barrel, below the 16-inch minimum, so a civilian build like it falls under NFA rules. State laws vary, so check current rules first; this is general information, not legal advice.
Heckler & Koch G3 Fit and Length of Pull
The fixed polymer stock on the Heckler & Koch G3A3 has a single length, so it suits some body sizes better than others. Try the rifle on your shoulder before you buy.
The Heckler & Koch G3A4 stock slides in and out, so you can adjust your reach. That flexibility is the main gain beyond a shorter G3 rifle length.
FAQs About G3 Rifle Length
How long is a G3 rifle?
About 1,023 mm (40.3 in) for the standard G3A3 with a fixed stock.
How long is the G3 barrel?
It is 450 mm (17.7 in) on standard models and 315 mm (12.4 in) on the G3KA4.
How long is a G3A4 with the stock collapsed?
About 840 mm (33.1 in) collapsed, versus 1,020 mm (40.2 in) extended.
How much does a G3 weigh?
Most sources list 4.1 to 4.7 kg (9.0 to 10.4 lb) unloaded, depending on the variant.
Is a G3 longer than an AR-15?
Yes. A G3A3 is over 7 inches longer than a fully extended M4 carbine.
What magazine does a G3 use?
A 20-round box magazine in 7.62×51mm NATO, with 30-round and drum options available.
What is the shortest G3 variant?
The G3KA4, at about 711 mm (28.0 in) with the stock collapsed.
Is the HK91 the same length as the G3?
Nearly. The HK91 is listed at about 40.5 in versus 40.3 in for the G3A3.
Conclusion
How long is a G3 rifle? About 1,023 mm (40.3 in) for the standard G3A3, down to 711 mm (28.0 in) for a collapsed G3KA4.
Barrel, stock and accessories decide the final G3 rifle dimensions, so match the numbers to your exact variant.
Use the conversions and comparisons above whenever you need a fast size check.
Sources:
- Small Arms Survey – HK G3
- Modern Firearms – HK G3
- Gun Mag Warehouse – HK G3 overview
- Weapon Systems – HK G3
- HK Parts – HK91 and G3
- Guns & Ammo – G3 overview
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Related product: Rifle hard case for a G3 rifle. As an Amazon Associate, I earn from qualifying purchases.
Hi, I’m Michael Carter, I write simple, everyday size guides so you can picture any measurement in seconds.