Shopping Cart

Surefire SCAR 17/MK20 Shoulder Ring.


In stock

Purchase this product now and earn 10 Points!

Product Details

PMM Is proud to now carry the Surfire 762 Shoulder Ring, The Surfire shoulder ring is now being used as a Standard in all PMM SCAR 17 CQC Barrel jobs.

PMM has used it on several other Custom barrel jobs that required a larger Shoulder for the Muzzle device to mate with.


PMM Highly Recommends the USE of the Surefire SCAR Should ring on ALL SCAR 17/MK20 Barrel’s, PMM Will not be held responsible for Baffle strikes on any PMM CQC barrel jobs Not using this ring to insure Proper Muzzle device Alignment.


The Surefire shoulder Ring solves all of the issues with fitting muzzle devices and suppressors to the FN SCAR 17/MK20 rifle. Due to the small shoulder available on the SCAR 17S barrel from the factory, there are a very limited number of muzzle devices and mounts that will work properly. This ring increases the size of the shoulder by spreading the load of of the shoulder ring uniformly agains the barrel shoulder. It also reduces the length of the muzzle threads to 0.60”, allowing any device or suppressor to be properly mounted.



  1. Verify that the rifle is unloaded and made safe
  2. Thoroughly clean the entire muzzle thread profile of any debris, such as dried thread locker
  3. Slip the surefire Ring over the muzzle with the ID chamfer facing towards the muzzle device not the barrel
  4. If installing a brake, space out and add the required washers or shims as needed to index properly
  5. Clean, degrease, and dry the threads on the muzzle, and in the muzzle device
  6. Add a few drops of the supplied Surefire Rocksett to the muzzle threads and threads of the muzzle device
  7. Thread muzzle device onto the muzzle and snug ensuring the Ring is seated correctly
  8. Torque the muzzle device, but do not exceed 35 ft-lbs
  9. Before firing, always verify proper bore alignment of any muzzle device and/or suppressor!


​PMM Surefire Shoulder Ring Install Video for the FN SCAR 17 Barrel.

Additional information

Weight 0.05 lbs

21 reviews for Surefire SCAR 17/MK20 Shoulder Ring.

  1. Robert N.

    Worked perfectly. Exactly what was needed for the modification!!

  2. Shawn N.

    I was really disappointed. I thought I would receive a custom part machined by PMM. This is just the shim kit and spacer that comes with the Warcomp and other Surefire muzzle devices. I was looking for something beefier, as the stock parts did not work for me. This went straight into my junk drawer; did not even open the package. Looks like I need to get on my lathe and machine my own part.

  3. Ben A.

    This shoulder ring works great! I was able to attach a SilencerCo ASR brake and a SAKR 762 silencer easily! This is a must have if your are a SCAR owner.

  4. Benjamin

    Just what I needed. Although designed for the SCAR 17, it worked great on my T/C Compass 6.5mm Creedmoor. The threaded portion of the rifle barrel did not have enough shoulder to allow proper timing of a suppressor ready QD muzzle brake using shims. The PMM Surefire SCAR 17/MK20 Shoulder Ring gave me enough shoulder to properly time the brake. Will definitely buy another if the need arises.

  5. Martin D.

    Great kit, and not insanely overpriced like another certain shop.

    For the price of a bottle of rocksett, you get the ring, shims, and rockset! Great value and worked like a charm.

Only logged in customers who have purchased this product may leave a review.

Best Sellers:

  • image_20
    From: $153.50 Select options
  • From: $114.75 Select options
  • image_1
    $52.00$57.00 Select options
  • $160.00 Add to cart

Products we support