
Availability: In Stock
The B5 Systems Modular Picatinny stock is a versatile, purpose-built buttstock designed for AR platforms and other rifles that accept 1913 Picatinny mounts. Built from durable composite and steel, this stock combines modern ergonomics with practical modularity—giving you an adjustable cheekpiece, collapsible length of pull, and secure sling attachment options all in one assembly. Whether you're running a precision rifle, tactical carbine, or hunting platform, the B5 Modular delivers the kind of rock-solid feel and adjustability that serious shooters expect.
What sets this stock apart is its thoughtful design for real-world use. The spring-assisted cheekpiece adds approximately 1/2 inch of height and deploys smoothly—open it by pulling back and pushing up; close it by pulling back and pushing down. The integrated left-side folding steel hinge lets you collapse the stock for storage or transport without removing it. A cushioned, nonslip buttpad keeps the gun planted firmly against your shoulder, even in harsh conditions or over extended shooting sessions.
Attachment is simple and rock-solid: the stock mounts directly to any 1913 Picatinny rail via the integrated interface. Fixed sling mounts and steel quick-disconnect (QD) mounts with anti-rotation detents give you multiple ways to sling your rifle. The color-matched steel hardware integrates cleanly with the composite body, and everything is made right here in the USA. At 16.8 ounces, it's substantial enough to feel premium but won't bog down your rifle.
| Brand | B5 Systems |
| Mount Type | 1913 Picatinny |
| Material | Composite with steel hardware |
| Length of Pull Adjustment | Collapsible, 2 1/4" range |
| Cheekpiece Height | Adjustable, adds approximately 1/2" |
| Hinge | Left-side folding steel |
| Sling Mounts | Fixed and quick-disconnect (QD) with anti-rotation |
| Weight | 16.8 oz |
| Overall Length | 8.06 in |
| Width | 1.76 in |
| Height | 4.67 in |
| Country of Origin | USA |
This stock mounts to any rifle or upper receiver with a 1913 Picatinny rail. That includes most AR-platform rifles, precision rifles, and other modern sporting rifles equipped with a Picatinny interface. Verify your firearm has a Picatinny rail before purchase.
Yes. The stock features a collapsible design with a 2 1/4" range of length-of-pull adjustment, letting you dial in the fit for your body size, shooting stance, and gear setup.
The cheekpiece is spring-assisted and adjustable. To deploy it, pull back and push up; it adds approximately 1/2" of height to help align your eye naturally with your optic. To stow it, pull back and push down. The spring assist makes the motion smooth and repeatable.
Yes. An integral left-side folding steel hinge allows you to collapse the stock without removing it from the rifle, making it compact for transport or storage while keeping the assembly intact.

SKU: 144602549 • Width: 6.55in • Weight: 1.305oz





Availability: In Stock
The B5 Systems Modular Picatinny stock is a versatile, purpose-built buttstock designed for AR platforms and other rifles that accept 1913 Picatinny mounts. Built from durable composite and steel, this stock combines modern ergonomics with practical modularity—giving you an adjustable cheekpiece, collapsible length of pull, and secure sling attachment options all in one assembly. Whether you're running a precision rifle, tactical carbine, or hunting platform, the B5 Modular delivers the kind of rock-solid feel and adjustability that serious shooters expect.
What sets this stock apart is its thoughtful design for real-world use. The spring-assisted cheekpiece adds approximately 1/2 inch of height and deploys smoothly—open it by pulling back and pushing up; close it by pulling back and pushing down. The integrated left-side folding steel hinge lets you collapse the stock for storage or transport without removing it. A cushioned, nonslip buttpad keeps the gun planted firmly against your shoulder, even in harsh conditions or over extended shooting sessions.
Attachment is simple and rock-solid: the stock mounts directly to any 1913 Picatinny rail via the integrated interface. Fixed sling mounts and steel quick-disconnect (QD) mounts with anti-rotation detents give you multiple ways to sling your rifle. The color-matched steel hardware integrates cleanly with the composite body, and everything is made right here in the USA. At 16.8 ounces, it's substantial enough to feel premium but won't bog down your rifle.
| Brand | B5 Systems |
| Mount Type | 1913 Picatinny |
| Material | Composite with steel hardware |
| Length of Pull Adjustment | Collapsible, 2 1/4" range |
| Cheekpiece Height | Adjustable, adds approximately 1/2" |
| Hinge | Left-side folding steel |
| Sling Mounts | Fixed and quick-disconnect (QD) with anti-rotation |
| Weight | 16.8 oz |
| Overall Length | 8.06 in |
| Width | 1.76 in |
| Height | 4.67 in |
| Country of Origin | USA |
This stock mounts to any rifle or upper receiver with a 1913 Picatinny rail. That includes most AR-platform rifles, precision rifles, and other modern sporting rifles equipped with a Picatinny interface. Verify your firearm has a Picatinny rail before purchase.
Yes. The stock features a collapsible design with a 2 1/4" range of length-of-pull adjustment, letting you dial in the fit for your body size, shooting stance, and gear setup.
The cheekpiece is spring-assisted and adjustable. To deploy it, pull back and push up; it adds approximately 1/2" of height to help align your eye naturally with your optic. To stow it, pull back and push down. The spring assist makes the motion smooth and repeatable.
Yes. An integral left-side folding steel hinge allows you to collapse the stock without removing it from the rifle, making it compact for transport or storage while keeping the assembly intact.
SKU: 144602549 • Width: 6.55in • Weight: 1.305oz
