How Does The HK MP7 Actually Work Inside?

🔧 Operating System:
Short-stroke gas piston: The MP7 uses a gas-operated system similar to the HK G36 or even the AR-18. Gas is tapped from the barrel and drives a small piston back to cycle the bolt.

This makes it ultra reliable, especially compared to direct impingement systems (like the M16/M4).

🧠 How It Cycles:
Round fired → expanding gases push the bullet forward.

A portion of gas is tapped off through a gas port near the front of the barrel.

This gas drives a piston rearward.

The piston hits the bolt carrier group (BCG), sending it backward.

The rotating bolt unlocks, ejects the spent casing.

As the bolt group travels back, it compresses the recoil spring.

Recoil spring pushes the bolt group forward again.

New round is stripped from the mag, chambered, bolt locks = ready to fire again.

⚙️ Bolt + Barrel Group:
The rotating bolt has multiple lugs, ensuring a secure lock-up.

It’s actually quite overbuilt for the size of the gun — more like a rifle bolt than a typical subgun.

🔫 Fire Control & Modes:
Selector switch: Safe / Semi / Full-auto (some models have 2-round burst).

It has a closed-bolt firing system, which helps with accuracy.

The trigger group is designed to be modular and is integrated into the lower receiver.

📦 Construction & Design:
Monolithic upper receiver is polymer with steel inserts where it matters.

Rails for optics and accessories.

Folding foregrip integrated under the handguard for stability.

Telescoping stock: Makes it compact for carry, extends for shoulder firing.

💥 Ammunition (4.6×30mm):
High-velocity, armor-piercing-capable.

Very low recoil, letting you dump mags full-auto with surprising control.

It’s not a pistol round — it’s designed to defeat soft body armor, which is why the MP7 is a favorite for special forces.

Would you like a labeled diagram of the internals or animation-style breakdown to go with this?