Carlson's 8-Shot Magazine Extension Assembly for 12 Gauge Browning Invector Plus

Carlson's 8-Shot Magazine Extension Assembly for 12 Gauge Browning Invector Plus increases magazine capacity, improves reload speed, and ensures reliable feeding for shotguns using the Browning Invector‑Plus (INV+) style magazine tube. Designed for hunters, competitive shooters, and upland applications, this precision extension delivers durable performance, safe installation, and consistent function.

Product Description

The Carlson’s 8-Shot Magazine Extension Assembly adds extra shell capacity to standard 12 gauge shotgun magazines, depending on choke and shell length. Constructed from machined aluminum with a corrosion-resistant finish and stainless steel internals, it is engineered for long-lasting durability and smooth feeding. The assembly includes spring, follower, end cap, and detailed instructions for easy installation on Browning Invector‑Plus compatible tubes.

Key Features & Benefits

• Increased Capacity — Adds extra rounds for extended shooting, upland hunts, and competitive stages.

• Browning Invector‑Plus Compatibility — Specifically designed for 12 gauge barrels and magazine tubes with INV+ thread pattern.

• Precision Machining — CNC machined aluminum and stainless steel internals ensure a tight, reliable fit.

• Reliable Feeding — Optimized follower and spring reduce jams and ensure smooth cycling with 2¾" and 3" 12 gauge loads.

• Corrosion-Resistant Finish — Hard-coat anodized exterior resists weather and wear.

• Tool-Free End Cap Removal — Simple design allows fast installation and maintenance.

• Lightweight Design — Minimal weight preserves shotgun balance for comfortable carry.

• Complete Kit — Includes extension tube, spring, follower, end cap, installation wrench, and instructions.

Specifications

Brand: Carlson’s
Model: 8-Shot Magazine Extension Assembly (12 Gauge)
Compatibility: 12 gauge shotgun barrels/magazine tubes using Browning Invector‑Plus (INV+) pattern
Materials: CNC machined aluminum, stainless steel spring and follower, hard-coat anodized finish
Capacity Increase: Adds up to 2 rounds (depends on choke and shell length)
Shell Length Support: 2¾" and 3"
Dimensions: Extension length 3.0"–3.5", outer diameter matched to INV+ tube standard
Weight: 4–6 oz
Included: Extension tube, spring, follower, end cap, installation wrench, instructions
Warranty: 1-year limited manufacturer warranty

Why Choose Carlson’s 8-Shot Extension

• Field-Proven Reliability — Engineered for consistent feeding and low maintenance.

• Manufacturer Quality — Precision fit and durable finish from Carlson’s.

• Quick Installation — Straightforward assembly on INV+ tubes with common tools.

• Maintains Handling — Minimal added weight preserves balance and carry comfort.

Usage & Installation Instructions

1. Verify your shotgun uses Browning Invector‑Plus (INV+) style magazine tube.

2. Unload the firearm and follow all safety procedures; remove magazine spring and follower per shotgun manual.

3. Thread Carlson’s extension onto the magazine tube following included instructions; install spring, follower, and end cap.

4. Cycle dummy rounds or snap caps to confirm smooth feeding and correct function before live use.

5. Recheck tightness after the first range session and periodically thereafter. Confirm 3" shell function with host shotgun manufacturer guidance.

Compatibility & Safety

• Confirm INV+ thread type on your barrel or consult the shotgun manufacturer before purchase.

• Using an incorrect thread pattern or improper installation may damage the magazine tube or cause feeding issues.

• Always follow firearm safety rules and manufacturer instructions when modifying magazine components.

Carlson’s 8-Shot Magazine Extension Assembly provides added capacity and reliable performance for 12 gauge shotguns with Browning Invector‑Plus tubes, making it an essential upgrade for hunting, competition, and extended shooting sessions.