Good afternoon everyone and welcome back to TFB’s Silencer Saturday brought to you by Yankee Hill Machine, manufacturers of the new YHM Turbo T3 5.56 rifle suppressor. Last week we got a look at the SilencerCo VELOS LBP low back pressure 5.56 rifle suppressor. This week, since flooding and mud is keeping us off the range, we take a look at a small suppressor life hack that might save you some headaches – the Precision Armament Accu-Washer Muzzle Device Alignment System. Are you ready to shake off peel washers, shims, and tolerance stacking? Let’s take a look.

More @ TFB:

• SILENCER SATURDAY #155: Is The YHM NITRO N20 The Best Universal Suppressor?
• SILENCER SATURDAY #12: Direct Thread Vs Quick Detach

Items seen in today’s episode:

• MCX Virtus – 6.75” – 300BLK
• YHM NITRO N20 Multi-Host Suppressor 
• Midwest Industries MCX Handguard – 6”

SILENCER SATURDAY #273: Precision Armament Accu-Washer System

If you have purchased a muzzle brake or another type of directional muzzle device in the past, chances are it came with a small baggie if shiny rings. These washers range in thickness from paper thin to penny thick and are designed to sit between the barrel’s shoulder and the muzzle device to accurately “time” the geometry of the the muzzle blast to assist with felt recoil. One or more washers are used to make the length of the barrel’s threading exactly the same as what is required for the muzzle brake.

As a reminder, crush washers should never be used with QD suppressor mounts and muzzle devices. The compression used to properly time the device can me applied unequally which can make your silencer off axis, increasing the risk of damage. Also, flash hiders don’t usually need to be timed.

Peel washers or shims are a necessary evil. If you want your muzzle device to work as advertised and also be a silencer mount, the correct number of peel washers needs to be used and the muzzle device needs to be torqued to the correct specifications. In the past I have used up to four or five washers to get the perfect orientation of the mount.

There is a better way.

Last year I purchased two sets of the Precision Armament Accu-Washer system and promptly lost them. While cleaning the workshop today, I found them and figured that a rainy day is as good as any as to try them out.

The difference between peel washers or shims and the Accu-Washer system is that instead of using multiple washers of varying sizes, they use only one washer to obtain the desired thread length.

Accu-Washer Specifications:

• Manufacturer’s Page: https://precisionarmament.com/accu-washer-muzzle-device-alignment-system/
• User Manual
• Model: AWS-500 / AWS-625
• Thread Size: 1/2×28 / 5/8×24
• Outer Diameter: 0.750” / 0.825”
• Thickness: 0.060”-0.094” / 0.060”-0.100”
• Material: 400 Series Stainless Steel
• Finish: Oxide Blasted, Matte Grey
• SKU: A02119 / A02219
• MSRP: $24.99

Simply choose the correct size Accu-Washer® shim to accurately index your muzzle brake or flash suppressor while maintaining perfect bore alignment. Since only one shim is required, the tolerance stackups and complexities associated with peel washers and other multi-shim systems are eliminated. This minimizes the risk of baffle strikes, ensuring maximum accuracy and safety from your muzzle brake or suppressor. Includes 18 individually marked Accu-Washer™ shims (timing adjustable from 0-360 degrees in 20-deg increments) and easy to follow instructions. Precision machined from high strength 400 series stainless steel to a guaranteed thickness uniformity of ±0.0001″. All shims feature an oxide blasted non-reflective surface finish for low visibility. One Accu-Washer System will align approximately nine brakes (on average) before replenishment shims are needed. Designed to fit 1/2-28 or 5/8-24 threaded barrels.

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First, ensure that the threads and shoulder of the barrel are clean and free of debris.

Check the timing of your muzzle brake by threading it on. You have a 1:36 chance of not requiring any additional timing. I don’t like those odds.

Once you identify the need for a Accu-Washer, use the thickest one, indicated by there large marks and three small marks, to determine the size of the Accu-Washer you’ll need for this setup.

By estimating the timing in degrees, you will be able to identify the number of additional degrees needed to properly time your muzzle device from the chart included on the installation instructions.

The system includes18 shims that increase in thickness enough to provide 20 degree increments of space between the barrel shoulder and the muzzle device shoulder. Estimate the number of degrees you need and check the chart.

Obviously it’s not an exact science and the amount of torque required will have an effect on the thickness of the Accu-Washer needed, but it only took me two tries to find the correct one. The main benefit is that you only need one washer to get the correct timing. No more tolerance stacking.

Some directional muzzle devices have only one orientation, others have two, which makes the distance or number of degrees, less and a smaller washer can be used. Based on probabilities, one kit should have at least three or for mounting options for other hosts and muzzle device mounting.

My suggestion is to first organize the Accu-Washers by size so that it is easy to find the right one after taking your initial measurements – it was like playing that flip-two-cards memory game as a kid. But after they were all organized, the process took about five minutes to get completely up and running. The best $24 I’ve spent in a long while.

Thanks for reading. Be safe, have fun, and we’ll see you back here next weekend for another Silencer Saturday.

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DEALERS: If you want your link to buy YHM suppressors included in future Silencer Saturday posts, email: silencers@thefirearmblog.com