MBX Competition 30+1 Spring & Follower for ALL 170mm 2011 FACTORY Magazines

**Must Be Paired with Magazine Extension to Extend Magazine to 171.25mm**

Engineered for maximum capacity, reliable feeding, and competition performance.

The MBX Competition Spring & Follower Kit upgrades compatible factory 170mm 2011 magazines with MBX's proven square-bottom competition spring and patent-pending competition follower. Developed through more than two years of testing, this system is designed to maximize magazine capacity while maintaining reliable feeding from the first round to the last.

Features

Designed for factory 170mm 2011 magazines
Patent-pending MBX Competition Follower
Proven 13-coil square-bottom competition spring
Optimized for maximum capacity and reliable feeding
Designed specifically for competitive shooting applications
Compatible with most factory-style 2011 magazine tubes

Compatible Factory Magazine Brands

Staccato
Check-Mate
Springfield Prodigy
SV Infinity
Atlas
Kimber 2K11
BUL Armory

Competition Follower Design

The patent-pending MBX Competition Follower was developed specifically for factory-style 2011 magazines. Combined with MBX's proven competition spring, it helps maximize capacity while presenting each cartridge at the proper angle for consistent feeding throughout the entire magazine.

Important Break-In Instructions

Before using your magazine in a firearm, load the magazine to full capacity 4-6 times.

This allows the spring to reach its working length and ensures the competition follower sits correctly below the feed lips. Failure to properly break in the spring can allow slide contact with the follower, potentially damaging the spring and follower.

Recommended Ammunition Specifications

Overall Length (OAL): 1.155" - 1.165"
Crimp: .372" - .374"
Round nose projectiles recommended
Avoid excessively short OAL and heavy crimps
Ensure primers are fully seated

Maintenance

Magazine springs are wear items. MBX recommends replacing competition magazine springs approximately every 6-8 months for shooters who regularly compete. High-volume shooters may require more frequent replacement.

Notes

Magazine tuning may be required depending on the manufacturer and condition of the magazine tube.
Factory tubes with damaged or out-of-spec feed lips may require adjustment.
The MBX follower is manufactured using a specialized 3D-printed material developed specifically for competition magazine performance.

Disclaimer: Magazine tube quality varies by manufacturer. MBX Competition Spring & Follower Kits are designed to provide reliable performance in properly manufactured and tuned magazine tubes using quality ammunition.