Sylvan Arms

Premium Quality and Affordability


AR-15 to 9mm Glock Conversion Block

(9 customer reviews)


The Sylvan Arms 9mm Glock Conversion Block is a drop-in fit to give you a 9mm capable lower without resorting to buying a pistol caliber-specific option. Designed to install in Mil-Spec lowers almost exactly like a standard rifle magazine.

  • Easy to install and swap out
  • Accepts popular Glock 9mm magazines
  • Designed to work with Mil-Spec lowers
  • Does NOT include last round bolt hold open

Product Details

  • Material: Steel and 6061-T6 Aluminum
  • Finish: Black Anodized
  • Weight: 4.2 oz.

Designed, built and assembled in the USA
100% Satisfaction Guarantee
Limited Lifetime Warranty

Check it out in action: Sylvan Arms 9mm Glock Conversion Block

If you have any questions, please contact us before ordering.

Install Video: 



NEW, Blemished

9 reviews for AR-15 to 9mm Glock Conversion Block

  1. Janz

    I’ve used dedicated glock-mag lowers from QC10, PSA, and New Frontier and have also install the TorkMag adapter so I’ve been around the block a bit with small-frame Glock use in AR form factor. I saw Primary Arms had a unit on sale and picked one up to test out. Frankly I was expecting at least some fussiness, however, this conversion block ran flawlessly with the 9mm upper I took out to test it with. Not one malfunction at all.

    Ran 115gr bulk Remington, some Federal bulk 115gr, some Blazer 147gr, and some PPU 147gr JHP. All worked w/o issue.

    Getting used to the position of the magazine release was a bit awkward (dedicated lowers and the TM kit all use the standard mag-release location), however, grabbing the mag and pulling the release with the off-hand index finger was easy to get used to. Mags do not drop free (at least in the one I picked up).

    I have to say I’m very pleased with this unit and have recommended it to my gun-owning friends that were looking into a glock-mag-fed 9mm AR, but didn’t want to buy a new dedicated lower (or mess with having to modify your mags like the TorkMag unit).

  2. Darryl

    It works well, but man is it tight to get in and the after market mags I am using are also a very tight fit. Just a hair more room would be great.

  3. Bill D (verified owner)

    I’ve shot about 500 rounds through my 9mm build, not a single malfunction. Ive used Glock, KCI and ETS with no issues. All mags fed and ejected normally. Hope you guys make one for the M&P9/40.

  4. Stan

    This unit is AWESOME!!!! I have two of them in different manufacturers lowers and they have been 100% in both lowers. Shot hollow point, fmg, flat point and they all have functioned perfectly. The ETS mags drop freely, the only ones that are a little tight are the factory Glock mags. I like the ETS mags better anyway.

  5. RtoR

    I purchased this to convert a 556 AR lower to 9mm. Works fantastic. Put 9mm barrel on an old 556 upper and added a $109 TRYBE Defense Milspec 9mm BCG and it simply works perfect. Barrel $139. This mag-well conversion and $109 BCG and I have a 9mm AR from an old 556 setup.

  6. Charles Dearth

    High quality piece. Slides freely into Superior Arms lower, very light resistance in my 17 Design Multi Cal. lower. 27 round promag ran flawlessly. I am very impressed. I love the mag release.

  7. Captain

    Works great in my Colt M16 and Palmetto State Armory lowers. Fit & Finish very nice, easy to install & remove, runs flawlessly in Full Auto & Semi, used Glock 19 & 33 round mags. Very happy and highly recommend.

  8. Curt Mills (verified owner)

    Better than sliced bread. Great fit. Carefully read instructions. Dug thru my 20 lbs.of hex keys. Found one! Installed the block. Tried 26 mag — almost, but no cigar. (I have two 17/19 mags coming) . However the 26 mag would cycle if I held it in (just to prove the block would function)(slid right in and out very smoothly tho). Went back inside, reread instruction and found the enclosed hex key. I highly recommend. Lrbho not an issue for me. Getting very close to having a “street legal” Ca AR 9. Thank you very much!

  9. Curt Mills (verified owner)

    This is the one to have. No lrbho, but not an issue for me. Works perfectly . My motto: an AR in every caliber. Wish Sylvan made one in 45acp. Maybe next week.

Add a review

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.