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AR-15 Custom 40 RD PMAGs

Make it yours

Upload any image or logo.
We print it on your PMAG 40-Round AR/M4.

Your logo, your dog, your unit patch, your own artwork. Drop it on the product, see exactly how it looks, then we print it in full color, never engraved.

  1. 1 Upload your art
  2. 2 Preview it on the product
  3. 3 We print and ship in 3-5 days
Upload your design From $60.00
Your design here PMAG 40-Round AR/M4 - Design Your Own

Shop our premade designs

Showing 1–24 of 44 resultsSorted by popularity

  • PMAG 40-Round AR/M4- Grim Reaper
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Grim Reaper

    Price range: $46.00 through $54.00
    + Quick add This product has multiple variants. The options may be chosen on the product page
  • PMAG 40-Round AR/M4- Simple Shark
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Simple Shark

    Price range: $46.00 through $54.00
    + Quick add This product has multiple variants. The options may be chosen on the product page
  • PMAG 40-Round AR/M4- Ghost Skull
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Ghost Skull

    Price range: $46.00 through $54.00
    + Quick add This product has multiple variants. The options may be chosen on the product page
  • PMAG 40-Round AR/M4- Joker
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Joker

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Woodland Camo
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Woodland Camo

    Price range: $46.00 through $54.00
    + Quick add This product has multiple variants. The options may be chosen on the product page
  • PMAG 40-Round AR/M4- Sprinkles
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Sprinkles

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- ATF
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- ATF

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Praying Hands
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Praying Hands

    Price range: $46.00 through $54.00
    + Quick add This product has multiple variants. The options may be chosen on the product page
  • PMAG 40-Round AR/M4- Shark
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Shark

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Brains
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Brains

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- BW American Flag
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- BW American Flag

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Hawaiian
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Hawaiian

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Mexico
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Mexico

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Cat Camo
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Cat Camo

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Tiger Stripe
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Tiger Stripe

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Blackbeard
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Blackbeard

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Red Clouds
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Red Clouds

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Samurai
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Samurai

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Great Wave
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Great Wave

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Cherub
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Cherub

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Snek
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Snek

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Jazz
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Jazz

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Santa Muerte
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Santa Muerte

    Price range: $46.00 through $54.00
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  • PMAG 40-Round AR/M4- Banana
    AR-15 Custom 40 RD PMAGs

    PMAG 40-Round AR/M4- Banana

    Price range: $46.00 through $54.00
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 Custom 40-Round AR-15 PMAGs — Magpul GEN M3 Extended 5.56 Magazines

Run more rounds between reloads with custom 40-round AR-15 PMAGs from My Southern Tactical. Built on the genuine Magpul PMAG 40 AR/M4 GEN M3 in .223 Rem / 5.56x45mm NATO, these are true factory extended-capacity magazines — not 30-rounders with a bolted-on baseplate.

That distinction matters. Aftermarket +10 baseplate extensions add length but reuse a spring that was never calibrated for the extra rounds, which is a common source of feeding failures and last-round hang-ups. A native 40-round body has factory-matched spring tension and a continuous internal curve designed from the ground up to feed all 40 reliably — exactly what you want in a high-volume range, competition, binary, or full-auto setup.

Then we make it yours. We apply full-color, high-definition direct prints to both sides of the extended body — flags, camos, custom text, or your own artwork through Design Your Own. These are true direct prints, not monochrome laser engraving, and the taller 40-round body gives your design even more canvas to stand out.

Shop our custom 40-round Gen M3 PMAGs below and personalize your high-capacity loadout without sacrificing reliability.

Advantages of a True 40-Round PMAG vs. Magazine Extensions

  • Factory-calibrated spring tension — a native 40-round magazine uses a spring engineered for the full round count, avoiding the weak-spring feeding failures common with +10 baseplate extensions on a 30-round body.
  • Continuous internal curve geometry — the body is molded with one uninterrupted feed curve, eliminating the binding and round-stacking issues that occur where an extension meets the original magazine.
  • Reliable to the last round — purpose-built geometry and spring rate help prevent the last-round hang-ups extensions are known for.
  • Impact-resistant polymer construction — Magpul’s polymer shell resists cracking and deformation under the heat and rough handling of high-volume shooting.
  • Built for high-volume fire — ideal for range, competition, binary, and full-auto setups where reload frequency and reliability matter most.
  • Durable, heat-tolerant custom print — our premium UV-curable inks are bonded to the body and built to hold up to the high heat and repeated handling of long range days.
  • More design canvas — the taller 40-round body offers extra surface area for bolder, more detailed full-color graphics.

Custom 30-Rd PMAG vs. Custom 40-Rd PMAG

Feature Custom Printed 30-Rd PMAG Custom Printed 40-Rd PMAG
Capacity 30 rounds 40 rounds
Base magazine Magpul PMAG 30 AR GEN M3 Magpul PMAG 40 AR/M4 GEN M3
Caliber 5.56x45mm / .223 Rem 5.56x45mm / .223 Rem
Approx. length ~7.6 in ~9.4 in (taller)
Ideal use case Home defense, carry, general/tactical use High-volume bench, range, competition, binary/full-auto
Graphic surface area Standard Larger — more room for custom designs
Print method Full-color HD direct print, both sides Full-color HD direct print, both sides
Reliability Proven Gen M3 performance Proven Gen M3 performance (factory 40-rd spring)

Frequently Asked Questions

Are these true factory 40-round magazines or modified 30-rounders?

True factory. These are genuine, unmodified Magpul PMAG 40 AR/M4 GEN M3 magazines — built as 40-round bodies from the factory with a matched spring and follower. They are not 30-round mags with an aftermarket baseplate extension.

Are these 40-round PMAGs engraved or printed?

Printed. We use a high-definition, full-color direct-print process — not laser engraving — for vibrant, multi-color designs on both sides of the magazine. The taller body gives even more room for detailed graphics that engraving can’t match.

Will a 40-round PMAG fit in standard AR-15 magazine pouches?

It depends on the pouch. The PMAG 40 is noticeably taller than a 30-round mag, so it seats deeper and sticks out more in standard pouches. Open-top or adjustable/elastic pouches work best; some fixed 30-round pouches won’t fully retain it.

Do you ship 40-round magazines to capacity-restricted states?

Some states and localities restrict standard- and extended-capacity magazines. Orders are subject to applicable local laws, so please confirm your area’s magazine-capacity rules before ordering.

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