www.mandofun.us

It can be a real PITA to keep track of all the obscure barrel threads out there - so I figured I'd put what I know here and then build on it over time.  That way it can serve as a reference for quickly locating how your barrel may be threaded. Just remember to double check everything. Of course ever manufacture has their own little nuances to make sure they can make it as much of a PITA for you. For example SilencerCo pistol cans uses Piston Adapters for their Osprey and Octane Series, and or fixed barrel spacers, to mute the booster assembly for rifle adaptation.

• M=Metric (for example - M13.5x1 LH means that the numbers are metric instead of standard.)
• LH=Left Hand (for example - M13.5x1 LH means the threads are backwards from what you typically expect.  This thread pitch would require righty-loosey, lefty-tighty...)
• RH=Right Hand (for example - M16x1RH means the threads work how you typically expect (righty-tighty...).  If there is no LH or RH designation - RH is the default.)

.22 LR, .22 MAG, .17 HMR The standard thread for these calibers is 1/2x28. 

• Many .22LR pistols (Ruger SR, Walther P22, Sig Mosquito, GSG 1911, etc) have barrels that are threaded underneath the slide, these pistols require an adapter that will move the threads in front of the slide and allow you to attach a silencer.
• Some CZ rifles use a 1/2x20 thread pitch and require an adapter.

• H&K weapons use the M13.5x1 LH thread pitch
• Sig Sauer weapons use the M13.5x1LH thread pitch - with an exception of the P320 variants which run New Hampshire made barrels in 1/2x28

• H&K weapons use the M14.5x1 LH thread pitch

• H&K USP Tactical uses the M16x1 LH thread pitch
• H&K Mark 23 (Socom) uses the M16x1 RH thread pitch

• Steyr Aug uses the M13x1 LH thread pitch
• H&K weapons use the M15x1 thread pitch
• Ruger Mini uses 9/16x24 thread pitch

• Sako TRG uses the M18x1 thread pitch
• Accuracy International uses the M18x1.5 thread pitch
• AK-47s use a number of different thread pitches

• M14x1 LH - This is the most common thread pitch for eastern European and most US made AK's
• M24x1.5 RH - This thread pitch is most often found on the gas/front sight block of AK-74 rifles
• M26x1.5 LH - A somewhat unique pitch that can be found on PAP92 or M85 Yugo builds.  Again, these rifles are threaded on the gas/sight block, not the barrel.

• Sako TRG uses the M18x1 thread pitch
• Accuracy International uses the M18x1.5 thread pitch
• Desert Tactical Arms uses the 3/4x24 thread pitch