
DESCRIPTION
IMPORTANT:
These are individually sold Accu-Washer shims. They are intended only for replacing shims used from the full 18 shim set which you must always purchase first. You WILL NOT be able to index or align your muzzle device by purchasing a single Accu-Washer shim.
You must always purchase the full 18 shim set for first time installations. Please refer to Accu-Washer Muzzle Device Alignment System if you have not purchased the full 18 shim set in the past.
FREQUENTLY ASKED QUESTIONS
The AccuWasher® Gen 2 is an upgraded version of the Precision Armament original single-shim muzzle device alignment system. It allows for precise, repeatable alignment of muzzle brakes, compensators, and suppressor mounts—eliminating the guesswork and inconsistency of peel washers and crush washers. Gen 2 features new shim sizes, thinner profiles, and adapter compatibility for broader use across different thread sizes and barrel profiles.
The Gen 2 system offers several improvements over the original:
Feature | Gen 1 | Gen 2 |
---|---|---|
Shim Sizes | 1/2” and 5/8” kits only | Now includes 1/2”, 5/8”, and 3/4” kits |
Outside Diameter (OD) | 1/2” shim: 0.750” | 1/2” shim: 0.725” (smaller for a sleeker fit) |
Shim Thickness | 5/8” shim: 0.060”-0.100” | 5/8” shim: 0.040”-0.080” (thinner for finer adjustment) |
Compatibility | Limited to fixed thread sizes | Now compatible with all common thread sizes and barrel profiles via shim adapters |
Interchangeability | 1/2” shims not compatible | 5/8” Gen 1 and Gen 2 shims are interchangeable |
Aesthetic | Standard fit | More flush and professional finish with adapters |
Each shim is laser-marked with a series of thick and thin dashes:
- Thick dashes = 5
- Thin Dashes = 1
For example, a shim with 4 thick dashes and 1 thin dash equals shim #21.
Use the included timing chart to determine which shim number aligns your muzzle device properly.
Absolutely. Despite all the added features and compatibility improvements, Gen 2 maintains the single-shim design, which offers better alignment, accuracy, and repeatability compared to systems requiring multiple stacked shims.
The reason the original 5/8” Accu-Washer® replacement shim is still available while the original 1/2” shim has been discontinued comes down to design compatibility between Gen 1 and Gen 2 systems.
Here's the breakdown:
- Original vs. Gen 2 - 1/2” Shim:
The outside diameter (OD) of the Gen 2 1/2” shim is 0.025” smaller than that of the original version. This dimensional difference makes the original 1/2” shim incompatible with Gen 2, and since Gen 2 is now the active production version, the original 1/2” shim was phased out. - Original vs. Gen 2 - 5/8” Shim:
The OD of the Gen 2 5/8” shim is identical to the original, even though the thickness range has been slightly reduced (for finer timing control). This means that original and Gen 2 5/8” shims are interchangeable, allowing the original 5/8” shim to remain available for purchase.
In short:
- ✅ 5/8” original shim = still compatible with Gen 2 → still offered.
- ❌ 1/2” original shim ≠ compatible with Gen 2 → discontinued.
We've created an easy-to-follow and detailed instruction manual with a printable timing chart. If you have questions, feel free to contact our service team:
Phone: 585-593-4972
Email: sales@precisionarmament.com
Reviews
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Simple and Very Effective
The Accu-Washer Shims are an awesome addition to my Armory. In the past I've used regular shims, and you have to use several of them to get the correct timing. Precision Armament has it figured out to just use one and done. Best part is it looks clean and professional. Both things I love and some of my customers have noticed. I would also like to add that they have an awesome customer support service. Michael was very helpful, and I was able to accomplish my goal with him making it easy, Thank you! If you are thinking about using these for your shims, just do it! They work and look great.
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Would recommend
This is by far the best system I have found for mounting muzzle devices.
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Accu-washer Shim
Precision Armamaments Accu-Washer Shim system is by far the best way to time a silencer mount or muzzle device on all your threaded firearms. We won't use anything else!
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accu-washer sim
The best on the market