QTR™ Stop

(9 reviews) Write a Review
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Product Overview

Now shipping with our new custom Torx T20 fastener!

QTR™ Stop - Our new QTR Stop is a wide hand stop for M-LOK forends, specifically for Sig Sauer MCX Virtus & Rattler U-rail systems. Designed as a lightweight solution to prevent shooters from slipping a hand in front of the muzzle, and filling the side gaps up to the rail to prevent heat exposure from muzzle blasts. Specifically designed for the 5.56 Rattler U-rail for a Foreign defense contract, the QTR Wide Stop works as intended on any Sig MCX Virtus / Rattler U-rails as well as many other M-LOK forend rails (see compatability list below). Its upward ears were designed to flow and mate specifically with the Sig U-rail profile to create a wide and seemless barrier. Made out of 7075 Aluminum and hard anodized in Carbon Black or Terra Bronze, and weighing in at just under half an ounce. The QTR Wide Stop takes up only 1/2 M-LOK slot at the end of the rail by utilizing a mini M-LOK recoil lug that hangs over the front lip of the rail. The QTR Wide Stop creates a perfect indexing point to bring the rifle on target securely and consistently. 

Ships Free and Made in USA

  • Mount Type: M-LOK
  • Footprint: 1/2-Slot
  • Height: 0.850" off rail, 0.150" upwards on the wings towards the rail
  • Length: 1.050"
  • Width: 1.450"
  • Weight: 0.56oz w/ hardware
  • Material: 7075-T6 Aluminum
  • Finish: Type 03 Hardcoat Anodizing
  • Color: Carbon Black®, Terra Bronze®
  • Hardware: US Made 416 Stainless M-LOK Nut
  • Fastener: US Made T20 Torx Fastener w/ Nylon Thread Patch

Fitment & Compatability, If you don't see your rail listed or have questions email

  • Sig Rattler U Rail - Regular Slot: Yes, Forward Lip: Yes
  • Sig Virtus U-Rail - Regular Slot: Yes, Forward Lip: Yes
  • Sig Virtus SD-Rail - Regular Slot: Yes, Forward Lip: Yes
  • Sig Canebrake Rail - Regular Slot: Yes, Forward Lip: No
  • Sig SPEAR-LT HG - Regular Slot: Yes, Forward Lip: Yes (May hang off if stacked)
  • Sig M400 Pro - Regular Slot: Yes, Forward Lip: Yes
  • Sig MPX/MPX-K MLOK HG: Regular Slot: Yes, Forward Lip: N/A
  • Lancer Systems MCX Gen 1 Carbon HG - Regular Slot: Yes, Forward Lip: No
  • Lancer Systems MPX Carbon HG - Regular Slot: Yes, Forward Lip: No
  • Daniel Defense RIS 3 HG - Regular Slot: Yes, Forward Lip: No
  • Noveske NSR-SD - Regular Slot: Yes, Forward Lip: No
  • Noveske NSR - Regular Slot: Yes, Forward Lip: No
  • Geissele MK16 HG - Regular Slot: Yes, Forward Lip: Yes
  • Q Honey Badger HG - Regular Slot: Yes, Forward Lip: No (Will not mount on slot where can is under rail)
  • KAC URX4 - Regular Slot: Yes, Forward Lip: Yes
  • HK 416/MR556 MLOK HG - Regular Slot: Yes, Forward Lip: No
  • B&T APC9-SD/APC45-SD MLOK HG - Regular Slot: Yes, Forward Lip: Yes
  • Midwest Industries MPX MLOK HG - Regular Slot: Yes, Forward Lip: No
  • BCM MCMR MLOK HG - Regular Slot: Yes, Forward Lip: Yes



© 2024 RailScales LLC All rights reserved. RailScales®, QTR, Carbon Black®, Terra Bronze® are registered trademarks of RailScales LLC.

For all patents and trademarks, see


(9 reviews) Write a Review

9 Reviews Hide Reviews Show Reviews

  • 4
    QTR stop

    Posted by John B. on Mar 30th 2024

    bought these along with the Karve-P, and G10 XOS-H. fits great on my 11.5 Sig mcx spear LT. has a slight overhang all together, but really enjoy it so far. will be glad to have it, once i get a dedicated suppressor.

  • 5
    Qtr stop

    Posted by Ashby moore on Mar 10th 2024

    Honestly just buy one, these guys products speak for themselves

  • 5
    Quality Product and Design

    Posted by Justin on Mar 9th 2024

    I was curious about this stop that was specifically designed for the MCX rail. The fit and finish on the QTR is excellent, provides a good amount of surface area for a stop without being bulky, and looks great on the MCX rail. It's small footprint also allows for plenty of options when it comes to placement.

  • 5
    QTR Stop

    Posted by Travis Odell on Feb 20th 2024

    Really great hand stop. It fits the DD MFR rail almost perfectly.

  • 5
    Best MPX/MCX Handstop

    Posted by Railscales Reviewer on Sep 12th 2023

    Excellent build quality and great feel.

  • 4
    QTR Handstop

    Posted by Ron on Mar 10th 2023

    Not gonna lie, I was a little disappointed with the fit on a Spear LT, but a prior review said was it was good to go. The QTR is definitely best shaped for a Virtus handguard. There is a significant gap between the wings of it and the Spear LT hand guard that creates a decent snag hazard. I made lemonade though, ordered two single slot rail scales and they fit perfectly into the gaps between the QTR and the handguard. I am super happy with the look and function now.

  • 5
    Near perfect fit for the Honey Badger!

    Posted by Zac Trigg on Feb 23rd 2023

    The QTR in Terra Bronze couldn’t match the Honey Badger’s color any better! It fits almost perfectly on the last slot of the handguard with just the slightest gap on the “wings” of both sides. Not enough to worry about. The QTR is extremely well-built, sturdy when mounted, and fits nicely against the hand with no rough or sharp edges. Highly satisfied. Worth the money.

  • 5
    QTR Stop

    Posted by Shadow on Jan 22nd 2023

    Fits my Honey Badger perfectly.

  • 5
    Great fit on the MCX Spear LT!

    Posted by Clint Moore on Jan 18th 2023

    Looks and feels great on the MCX Spear LT. Was a little hesitant in spending $100 on a handstop, but glad I made the decision to purchase it. The machining and finish are so far past the competition in terms of quality. Have to love railscales for their constant innovation & quality.