Muzzle Thread Pitch Database

How to read this table

Confidence grades

HIGH — the manufacturer's own product page, spec sheet, manual or factory accessory listing states the thread. MEDIUM — a reputable vendor, gunsmith, or established industry reference states it, but the manufacturer does not publish it. LOW — a single forum post, a chart with known errors elsewhere in it, or a claim that is contradicted by a better source. Low-confidence rows are included deliberately, because knowing that a widely-repeated figure is unverified is itself useful.

What this database does that the others do not

• Every row cites its source and carries a verification date. The reference charts most often linked to in this category publish no sources and no dates, which is why several of them are still repeating figures that stopped being true years ago.
• Model and variant, not just make and caliber. “Glock 9mm” is not an answer — Glock sells the same pistol with a metric left-hand barrel and an imperial right-hand barrel under different part numbers. So does SIG, keyed on whether the barrel has a loaded-chamber indicator. So does Steyr. So did KRISS, between two generations of the same gun.
• Conflicts are shown, not resolved. Where sources disagree we publish both claims with both sources so you can see that the question is open and go measure.
• Negative rows. Models that are widely believed to be factory-threaded but are not — the commercial SIG P320-M18, the Springfield Prodigy, the Ruger Mini-14 Ranch, several Mark IV 22/45 Lites with faux thread protectors — are listed, because a wasted order is a real cost too.

Coverage and what is missing

Version 1 covers threaded pistols, rimfire, pistol-caliber carbines and subguns, and AK-pattern and imported rifles. Bolt-action centerfire rifles and shotgun choke systems are deliberately out of scope for now — bolt guns are the worst-covered category anywhere and deserve a proper build rather than a thin one, and “shotgun thread pitch” queries are almost always about choke tube systems, which is a different taxonomy entirely.

Rows that could not be sourced were left out rather than filled with the conventional guess. Notable gaps we are actively working on: EAA/Tanfoglio Witness, Kimber's threaded models, Dan Wesson Discretion and Wraith, the IWI Uzi Pro, factory Glock 10mm, the exact Ruger Mini-14 changeover point between 9/16x24 and 1/2x28, and thread pitches for any Smith & Wesson factory threaded barrel — S&W lists five such SKUs and publishes the pitch for none of them.

On the SAAMI standard

SAAMI approved Z299.6, its suppressors standard, on 30 July 2025. It specifies not just thread pitch but shoulder diameter, bore datum and a 45-degree shoulder angle for the common classes — 1/2-28 UNEF-2A, 9/16-24, 5/8-24, 11/16-24, M18x1.5 and 3/4-24. It is the only citable primary standard in this space, and it is worth knowing that it does not cover .578x28 for .45 ACP, does not cover metric left-hand threads, and does not cover anything over .450 inch. Most of what is difficult about this subject lives in exactly those gaps.

Corrections

If you have a barrel that contradicts a row here, or a manufacturer source for something in our gap list, send it to us and we will update the row and log the change. We would rather be corrected than be another undated chart.

The most useful things you can send: a gauged measurement with the model, generation and part number; a manufacturer spec sheet or manual page for anything in the gap list above; or a photograph of a barrel marking that contradicts what we have published. Smith & Wesson, Kimber, Century Arms, Steyr and Red Circle Tactical all block automated access to their specification pages, so those makers can only be filled in by people who own the guns. Corrections are credited unless you ask us not to.