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Questions & Answers
Will these mounts work for both the Standard 509T and the Primary Arms ACSS 509T? I've seen that they have slightly different dimensions. Expert Answer

The American Defense Manufacturing Holosun 509T QD Mount will only work for the standard 509T. It is not compatible with the model that features the ACSS Vulcan reticle which uses a slightly different footprint.

by Ethan, Gear Expert, April 26, 2023
What is the height of each of these mounts? I have some non-standard iron sights and would like to confirm the height needed for cowitness. Expert Answer

The American Defense Manufacturing Holosun 509T QD Mount can be purchased at an absolute co-witness height, bringing the centerline of the optic to 1.4". A lower 1/3 option is available and will bring your centerline to 1.6", and the low height mount will bring your centerline to 1.2".

by Ethan, Gear Expert, May 18, 2022
Customer Reviews
Most Recent Reviews
Tom smithy by Tom, Verified Owner, May 4, 2025
Amazing fit and finish and high-quality American made product. Just not what I required for my current set up as it is not a 1.93 height. But will definitely be holding onto it for a future build. I would highly recommend it if this is what you are l...
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Most Recent Reviews
Great mount and customer service by Excursion6oh, Verified Owner, April 20, 2025
The mounts are higher than described but OP sent me a label for a free return and quickly sent out the other height mount no questions asked
Most Recent Reviews
excellent! by mtn Yoda, Verified Owner, October 19, 2024
I use Midwest industry and Larue mount but mostly choose American Defense Manufacturing. My wife needed a mount for one of her new shotguns. Quick detach is the way to go. This was a good price as is exactly what she needed for her red dot. Like many...
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Most Recent Reviews
Very Solid by Wizgoober, Verified Owner, July 6, 2024
Well constructed & finished. Bought this for a HS510 that got mounted to a Beretta 1301. Wished it was a little lower to co-witness with the factory sights, but…physics. Overall, I’m impressed with the fit & finish of the mount & it’s very solid o...
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Most Recent Reviews
Best low mounts by John Dorr, Verified Owner, June 16, 2024
These still add a little height and generally can't be used with sights. The base is also slightly longer than the small optic.
Most Recent Reviews
AMD 509T QD moint by LeeC, March 6, 2024
I wanted something small on a AR pistol platform. This riser was perfect and aligned my 509T with my Holosun 3x magnifier.
Read All 7 Reviews

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Product Info for American Defense Manufacturing Holosun 509T QD Mount

The AD-509T QD mount was developed for the Holosun 509T red dot for use on AR pistols and other weapon platforms requiring a small, light weight red dot system. The AD-509T QD mount is a one piece unit that offers low, co-witness and lower 1?3 co-witness optic height. Offered in both standard or TAC lever, it is precision machined from 6061 T6 aluminum and finished in hard coat T3 Mil-Spec anodize. It features the Patented QD Auto Lock Lever system to accommodate both in spec and out of spec rail systems.image

Specifications for American Defense Manufacturing Holosun 509T QD Mount:

Manufacturer: American Defense Manufacturing
Color: Black
Finish: T3 Mil-Spec Anodize
Gun Make: AR Platform
Gun Type: Pistol
Fabric/Material: 6061-T6 Aluminum
Red Dot Sights-Footprint: Holosun 509T
Optic Cut: Holosun HE509T
Condition: New

Features of American Defense Manufacturing Holosun 509T QD Mount

  • The AD-509T QD mount features the Patented QD Auto Lock Lever system.
  • Does not require proprietary tools for adjustment.
  • Can be adjusted with your finger or a flat blade screwdriver.
  • Lever can be configured to lock to the front or the rear.
  • Superior clamping surface to insure maximum rail engagement.
  • 30% lighter than our standard mounts.
  • Precision machined from 6061 T6 Aluminum.
  • Finished in hard coat type 3 Mil-Spec anodize for a rock hard lasting finish.
  • Features the Patented QD Auto Lock Lever system which is fully adjustable to fit both in spec and out of spec rail systems.

Package Contents:

  • American Defense Manufacturing Holosun 509T QD Mount

American Defense Manufacturing Holosun 509T QD Mount Orderable Models

List of Orderable Models

  • American Defense Manufacturing Holosun 509T QD Mount, Tactical Legacy Lever, Lower 1/3 Co-Witness Mount Height, Black, AD-509T-11-TAC , MPN: AD-509T-11-TAC , UPC: 810008517840 , Code: 26S-RMT-AMDEF014-AD-509T-11-TAC
  • American Defense Manufacturing Holosun 509T QD Mount, Standard Legacy Lever, Low Height, Black, AD-509T-L-STD , MPN: AD-509T-L-STD , UPC: 810008517789 , Code: 26S-RMT-AMDEF014-AD-509T-L-STD
  • American Defense Manufacturing Holosun 509T QD Mount, Tactical Legacy Lever, Low Height, Black, AD-509T-L-TAC , MPN: AD-509T-L-TAC , UPC: 810008517796 , Code: 26S-RMT-AMDEF014-AD-509T-L-TAC
  • American Defense Manufacturing Holosun 509T QD Mount, Tactical Legacy Lever, Co-Witness Mount Height, Black, AD-509T-10-TAC , MPN: AD-509T-10-TAC , UPC: 810008517826 , Code: 26S-RMT-AMDEF014-AD-509T-10-TAC
  • American Defense Manufacturing Holosun 509T QD Mount, Standard Legacy Lever, Lower 1/3 Co-Witness Mount Height, Black, AD-509T-11-STD , MPN: AD-509T-11-STD , UPC: 810008517642 , Code: 26S-RMT-AMDEF014-AD-509T-11-STD
  • American Defense Manufacturing Holosun 509T QD Mount, Standard Legacy Lever, Co-Witness Mount Height, Black, AD-509T-10-STD , MPN: AD-509T-10-STD , UPC: 810008517819 , Code: 26S-RMT-AMDEF014-AD-509T-10-STD

American Defense Manufacturing Holosun 509T QD Mount Unavailable & Discontinued Models

List of Unorderable Models

  • USED American Defense Manufacturing Holosun 509T QD Mount, Tactical Legacy Lever, Co-Witness Mount Height, Black, AD-509T-10-TAC, EDEMO2, Used, Condition Fair , MPN: AD-509T-10-TAC-EDEMO2 , Code: 26S-RMT-AMDEF014-AD-509T-10-TAC-EDEMO2
  • Open Box, Dealer Demo, American Defense Manufacturing Holosun 509T QD Mount, Tactical Legacy Lever, Low Height, Black, AD-509T-L-TAC , MPN: AD-509T-L-TAC-DMO , Code: 26S-RMT-AMDEF014-AD-509T-L-TAC-DMO
  • Open Box, Dealer Demo, American Defense Manufacturing Holosun 509T QD Mount, Tactical Legacy Lever, Lower 1/3 Co-Witness Mount Height, Black, AD-509T-11-TAC , MPN: AD-509T-11-TAC-DMO , Code: 26S-RMT-AMDEF014-AD-509T-11-TAC-DMO
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