Reviews & Ratings for Stern Defense MAG-ADMP45 AR-15 M&P .45 ACP Magazine Conversion Adapter

Stern Defense MAG-ADMP45 AR-15 M&P .45 ACP Magazine Conversion Adapter

$240.41 $186.99 Save 22%

View Product

Write a Review

Compare (0)

Most Helpful Positive Review Great Mag-Ad

Purchased this a year ago, had all sorts of problem with feeding. Contacted Stern, they pointed me in the right direction. If you go this route, you HAVE to use the Stern bolt and 11oz buffer. Believe me, don’t use anything else. I was using A Foxtrot bolt, that’s a no go. The Stern bolt is machined...
Read More...

Most Helpful Negative Review Not high capacity

Only uses M&P 45 magazines, 13 rounds maximum. Mags are $50. I should have bought the dedicated receiver for $130.the magazine release is awkward. However there are limited options if you want to shoot 45 on this platform.

Show

Sort by

Filter by

Stern Defense 45 mag adapter

by Dark2Dark, Verified Owner from MT, United States Written on September 26, 2026

Very precise and solid construction. Insightful engineering throughout. Correct set up takes some care, but no issues with a one-try set up. Works perfectly with factory S&W mags, but promag are too tight for reasonable mag changes. Mag release location takes a little getting used to for an AR, but it works perfectly. Pleasantly surprised with this adapter.

Was it helpful to you? Yes | No

AR Magazine Adapter

by Liccian, Verified Owner from VA, United States Written on June 30, 2026

I received this adapter defective. Unfortunately, it was simply placed in a plastic bag then in a shipping bag. I have returned it for a replacement. I have the AD9 and it is perfect. So, although this one was defective, I think this would be also perfect if not damaged. Looking forward to receiving a replacement.

Pros:

None

Cons:

not easy to swap lowers

Was it helpful to you? Yes | No

worked as described, well made, easy install

by saint, Verified Owner from AZ, United States Written on May 19, 2026

If you are building an AR45 with a standard ar15 lower, this works great, it is expensive, but there are very few options

Pros:

FITS AND FEEDS GREAT

Cons:

Expensive

Best Used for:

AR 45 with AR 15 lower

Was it helpful to you? Yes | No

Great mag adapter

by Lowrider6618, Verified Owner from FL, United States Written on June 21, 2025

This mag adapter was easy to install on my AR 15 lower.

Pros:

Work as advertised

Cons:

None

Was it helpful to you? Yes | No

45 mag. Conversion

by Cutter, Verified Owner from TN, United States Written on March 2, 2025

Good quality made product would recommend to anyone that has been looking for one

Was it helpful to you? Yes | No

Stern Defense Mag-admp45

by Jim, Verified Owner from UT, United States Written on January 17, 2025

The Stern Defense MAG-ADMP45 is a slick piece of engineering. It allowed me to build an AR-45 without the need to purchase a caliber specific lower. I already had a complete AR-15 lower; I simply needed a 10oz buffer weight and spring to complete lower receiver. The Stern Defense adapter uses M&P45 magazines which I find are very sturdy and reliable. It took no time at all to get used to the new mag release placement. The only negative I can place on this item is it is kind of expensive.

Pros:

easy to install
Exceptional engineering
positive magazine release button
Solid no movement after heat cool cycles

Cons:

Expensive
would rather have the white Stern Defense on the bottom rather than the side

Best Used for:

Convert AR-15 to AR-45

Was it helpful to you? Yes | No

Easy and works!

by Michael Whittlesey, from TX, United States Written on October 27, 2024

It took me about 10 minutes to install and worked just like it was part of the gun. I tried it on a different lower, and same result, works well.

Was it helpful to you? Yes | No

Foxtrot Mike integration

by Tk, from CA, United States Written on October 9, 2024

It works perfectly well with a foxtrot mike 45acp BCG as long as you modify the bolt by shaving off a little bit from the underside at the front so it doesn’t slam into the ramp and also clean up the extractor pin. I have now shot around 150 rounds with zero failures. Couple this rig with a 10 ounce buffer and it works pretty well except in the very beginning the extractor was damaging the casings by slamming into them and bending the Rim a little bit

1 of 1 found the following review helpful.

Was it helpful to you? Yes | No

Excellent conversion

by Ralph, Verified Owner from MI, United States Written on August 6, 2024

Excellent piece for any 9mm,45ACP AR15 platform conversion build. Works perfect with no flaws

Was it helpful to you? Yes | No

Working flawlessly

by Busy working, Verified Owner from NY, United States Written on November 22, 2023

Product works as advertised and is easy to install. Great buy

Pros:

Flawless operation

Cons:

None

Best Used for:

45 acp

Was it helpful to you? Yes | No

There are no reviews that match your criteria. Would you like to review this product?

FREE SHIPPING on Over 250,000 Products

Enjoy our FREE RETURNS

Reviews & Ratings for Stern Defense MAG-ADMP45 AR-15 M&P .45 ACP Magazine Conversion Adapter — 14 reviews — Page 1