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S.I.R. Systems

The Most Advanced Handguard in the World!


The A.R.M.S.® S.I.R.® System can provide a multitude of modular capabilities for accessories such as, thermal imager, lasers, night vision, optical sight, M203, etc.

The A.R.M.S.® S.I.R.® System has more unique and helpful features for the professional user than all other devices combined. Only the A.R.M.S.® S.I.R.® System allows you to have dovetail rails where you want them and not where someone else decided for you.  This modular receiver sleeve system is a hand guard universal mounting system that leaves the barrel totally free-floating while providing a rigid ultra-light platform on which to mount virtually any mission specific accessory.

  • Free floating barrel design to achieve maximum accuracy potential.
  • Removable side and bottom dovetail rail panels for mounting accessories such as lights, lasers and vertical forward grips.
  • Drastically enhanced cooling.
  • Lightweight and rugged aluminum construction.
  • Quick Change Lower Handguard.
  • Available in both Civilian(C) and Military(M) configurations. (Installation of Military S.I.R.® Variants requires removal of the Delta Ring/Handguard Retaining Ring).
  • The S.I.R. ® System is designed to fit mil-spec flat top receivers from Colt, Armalite, STAG, Rock River Arms, Barrett, CMT and Bushmaster in the 5.56 or 6.8 cal. carbine, mid, and rifle lengths. The #51 S.I.R.® Allows mounting to the carbine A1/A2 carry-handle. There may be other flat top receivers manufactured that the S.I.R.® may fit to properly, but we do not guarantee or warranty the S.I.R.® on any flat top receivers other than those listed above.


Benefits of the #50™M-CV:

  • Entire S.I.R.® front-end can be installed in less than 5 min. directly to the standard barrel nut without Delta ring. Totally Free Floating.
  • Front sight, gas tube, and front handguard retaining cap do not need to be removed.
  • Barrel does not have to be removed.
  • Standard barrel nut does not need to be removed.
  • Perfect alignment with the receiver can be accomplished via built-in alignment anti-rotation locking tabs.
  • No special tools required. S.I.R.® standard sling swivel is useable for installation.
  • The system weighs only 8.6 oz. The weight will increase depending on what selective rails are chosen to be utilized plus the weight of the sling swivel.
  • Hanguards complete with QD indirect airflow heat shield.
  • The S.I.R.® selective rails at 3, 6, and 9 o’clock positions can be exchanged, repaired, or replaced without removing the main top rail.
  • Super-cool offset heat venting.
  • The optional S.I.R.® rail also provides a modular means to cost-effectively upgrade into future integral electronics, and provide a solid platform, can eliminate the need to use high, less-stable, mounting devices, plus protects the top of the aluminum upper receiver at the same time protecting the receiver; can eliminate replacement of a damaged receiver.
  • The #50M-CV allows the M203 launcher to be free float attached with no modification whatsoever to the launcher’s receiver.
  • The #50M-CV allows the A.R.M.S.® dual QD 1913 M203 attachment brackets to install to the S.I.R.® upper handguard just like the polymer handguard.
  • The #50M-CV launcher QD attachment brackets provide a built-in 1913 dovetail rail along the length of the handguard at the 3 and 9 o’clock positions, multiple position attachment of grenade launcher sights.
*TM the distinctive shapes, styles, and appearances of all A.R.M.S.® S.I.R.® Systems are trademarks of A.R.M.S., Inc.

A.R.M.S.® products are proudly made in the USA