Precise alignment on 5/8 × 24 threaded barrels — twenty stainless shims in five calibrated thicknesses (0.004″ 0.008″ 0.012″ 0.020″ 0.040″) let you clock brakes or flash hiders on .30 / .308 / 7.62 mm and 300 BLK sporting platforms with fingertip torque, eliminating disposable crush washers and repeated trial-and-error during installation. | Fine 0.10 mm correction steps for barrel-nut setups — use a single 0.004″ shim for micro alignment or combine sizes for larger offsets, raising a free-float barrel nut in precise 35- to 173-degree increments, centring gas-tube ports and achieving consistent concentricity without exceeding 90 – 100 ft-lb that can strip threads. | Reusable 304 stainless steel resists galling, rust and heat — CNC-machined, deburred and bead-blasted to a non-reflective satin finish that won’t deform under torque; remove, clean and reinstall indefinitely so every muzzle device returns to its exact timed position after cleaning, barrel swaps or suppressor checks. | Clearly labelled, no-mix packaging saves bench time — each thickness ships in an ink-stamped bag with a quick-reference card, letting you grab the right shim instantly, prevent size mix-ups on a crowded workbench and finish builds faster instead of measuring tiny washers with calipers or micrometers. | Multipurpose shop tool beyond muzzle timing — precision shims level Picatinny rails, space scope-ring bases, true sizing-dies, replace shim-shell assortments in reloading presses and square fixtures on lathes or drill presses, making this 20-piece kit indispensable for builders, tinkerers and accuracy-focused enthusiasts.