Benelli M4 Won't Fit 7 Rounds in a 7-round Magazine Tube

Why Your Benelli M4 Often Only Holds 6 Rounds — Even with a 7-Round Tube (And What You Can Do About It)

The Benelli M4 is one of the most trusted semi-automatic 12ga shotguns on the market — rugged, reliable, and battle-proven. Yet one common frustration among shooters is the shotgun’s magazine capacity when using longer defensive 12-gauge shells. Let’s dive into why this happens and how simple upgrades can help you maximize your M4’s capacity and reliability.

12ga Shell Lengths: Not All “2¾” Are Created Equal

Shotgun shells are categorized by shell length — for example, 2¾", 3", and 3½". But within the same nominal length, different loads can physically vary in length due to how the crimp is formed. Two 2¾" shells from different companies can have completely different lengths — the 2¾" is the measurement of the shell before being crimped

• Defensive rounds (rolled crimps): These shells often have a rolled crimp that makes the cartridge body longer overall.
• Target or sporting rounds (folded crimps): These tend to have a folded crimp that keeps the shell shorter and more compact.

Even if both shells are marked as 2¾", the physical length of a rolled–crimp round can be significantly longer than a folded–crimp round. The Benelli M4’s magazine tube is already tight on capacity, and those extra millimeters add up — often resulting in:

• 6 rounds loaded smoothly
• 7th round won’t “lock-in” all of the way no matter how hard you push.

This is especially noticeable when loading 7 defensive rounds in a nominal 7-round tube.

Why the Benelli M4 Magazine Tube Struggles

The Benelli M4 uses a fixed tubular magazine designed for about 58mm of length per round. Defensive ammo with longer rolled crimps can:

• Exceed 62mm in length
• Reduce total usable space in the tube
• Cause binding, overlapping coils or magazine spring damage/wear.
• Prevent reaching the “full” 7-round count
• Even if specs say the tube will hold 7, real-world shell length matters.

Upgrade Solutions to Get Full Capacity and Smooth Feeding

Thankfully, shooters have reliable options to help the M4 realize its full capacity with longer defensive shells. Here are three upgrades that together can increase your magazine spring life, reduce stack pressure, and make that 7th round actually fit and easier to load.

Benelli M4 Titanium Magazine Cap

Upgrade your magazine tube end cap to a lightweight titanium replacement that reduces the weight at the muzzle and adds room in your magazine tube.

• Designed to give you an impressive 0.547” (13.9mm) of extra usable space in your
• magazine tube when used without the spring retaining ring.
• Reduces binding on the last round.
• Adds strength without weight.

Learn more → Benelli M4 Titanium Magazine Cap

Benelli M4 Max Room Follower

The Max Room Follower is a complete redesign of the OEM Benelli M4 follower. It is designed to minimize how much room the follower takes up in the magazine tube. shaped to help long defensive rounds seat more efficiently.

• It allows an extra 0.177” to 0.216” (4.5mm-5.5mm) of space in the tube depending how its measured.
• Perfect when longer crimps otherwise would prevent full tube capacity.

Grab it here → Benelli M4 Max Room Follower

Upgraded Benelli M4 Magazine Spring

A strong, high-quality replacement magazine spring can make all the difference in consistent feeding.

• Adds 0.10” (2.5mm) of magazine tube space
• Stronger springs help ensure the follower keeps pressure on longer, heavier, or longer shells.
• Works especially well in combination with the upgraded follower and titanium cap.

Check it out → Benelli M4 Upgraded Magazine Spring

Final Tips for M4 Shooters

Compare your ammunition on a flat surface and see which rounds are longer than others. 
Test your specific defensive loads — some will fit more easily than others.
Combine these upgrades for the best chance at true 7-round capacity.
Always cycle your shotgun after any magazine hardware changes to verify reliable feeding.

Wrap-Up

The Benelli M4 is capable of seven-round performance — but real-world ammo dimensions, especially with rolled crimps on defensive shells, often prevent it without modification. With the titanium magazine cap, max-room follower, and upgraded magazine spring, M4 owners can unlock full capacity and rock-solid reliability, even with longer, defensive 12ga rounds.