9MM Ammo Recommendations

9MM AMMO RECOMMENDATIONS

9mm PCCs on the AR platform behave very differently depending on barrel length, magazine type, and how the gun is tuned, so ammo choice and setup matter for reliability and terminal performance.

This guide separates rifle‑length and pistol‑length PCCs and gives the practical starting loads and tuning checks you should run in your exact lower, mag, and barrel.

Rifle‑length PCCs (16″+ barrels)

• Training / Range: 115–124 gr FMJ — cheap, feeds well, great for high‑volume practice and follow‑up drills.

• Duty / Self‑Defense: 124–147 gr JHP — reliable expansion from carbine barrels; test feeding and function in your lower/magazine config.

• Competition: 115–124 gr plated or match loads — lighter recoil for faster follow‑ups; tune gas/blowback or buffer system for consistency.

• Suppressed Use: 147 gr subsonic JHP or monolithic — quieter suppressed performance; chrono to confirm subsonic speed in your barrel.

• Build notes: Carbine barrels deliver higher velocity than pistols — you’ll see different terminal behavior vs handgun loads. Use appropriate AR‑9 magazines (Glock‑pattern, Colt SMG, etc.) and tune buffer/spring or gas system to handle the load spectrum.

Pistol‑length PCCs (Barrels Shorter Than 16”)

• Training / Function: 115–124 gr FMJ for feeding and cycling validation — some short barrels are picky, so start here.

• Carry / Home‑Defence: 124–147 gr JHPs proven to expand from short barrels — prioritize tested short‑barrel performance.

• Suppressed Pistol PCCs: 147 gr subsonic or specialty suppressed loads — heavy bullets keep velocity below supersonic threshold and improve suppressed terminal effect.

• Reliability tips: Short barrels and lighter loads often need recoil‑spring/buffer tuning or an adjustable gas block on gas‑delayed systems. Run long function tests (50–200 rounds) after any change.

• Feeding & mags: Magazine choice matters more in short, compact PCCs — verify reliable feed with the exact magazine and follower you’ll carry.

Tips for Best Results

• Chronograph & function‑test everything in the exact AR lower, magazine, and barrel length you’ll use.

• Start with one FMJ and one defensive JHP and validate feeding, extraction, and accuracy.

• Tune buffer/spring or gas system for short‑barrel and light‑load reliability — don’t assume a generic kit will run everything.

• Suppressed builds: prefer 147 gr subsonic or purpose‑built suppressed loads and test suppressed and unsuppressed cycling.

• Mags matter: use the magazine type your build is designed for and test +/- different followers if you see issues. ABC PCC lowers use Glock style magazines.