Confirmed Fitment
Sig Pro Magazine Loader
The Sig Pro is confirmed to fit the Super Thumb ST2, the loader ADCO builds for wide-body double-stack magazines. It loads Sig Pro magazines faster and with far less thumb strain — a purpose-built tool, not a one-size-fits-all compromise.
Why loading these magazines is a fight
Double-stack magazines get progressively harder to load as the spring compresses — the top few rounds are where thumbs give out. The Super Thumb pushes each round straight down against that spring tension for you, so topping off to full capacity takes seconds instead of sore thumbs.
Your Fit
Super Thumb ST2
Wide Body Double-Stack
Width
1.5" (38.6 mm)
Height
1.01" (25.4 mm)
Sig Pro loader — common questions
Which Super Thumb fits the Sig Pro?
The Sig Pro is a confirmed fit for the Super Thumb ST2. It appears on ADCO’s verified Super Thumb fit chart as an exact match.
What kind of magazine does the Pro use?
The Super Thumb ST2 is built for wide-body double-stack magazines, which is the class the Sig Pro uses.
Will the same loader work for my other Sig pistols?
Often, yes — many Sig models share the same magazine class. Check the other Sig fits listed below, or use the Model Finder to confirm your exact model before ordering.
Is the Sig Pro fit guaranteed?
Every Super Thumb is backed by a lifetime warranty. If you’re not certain, confirm with the Model Finder or call ADCO at 781-935-1799 before you order.
Not 100% sure? Confirm before you order.
Super Thumb loaders are model-specific. Use the Model Finder to double-check your exact firearm and magazine, or call ADCO Arms and we'll confirm the right loader for your Sig Pro. Every Super Thumb is backed by a lifetime warranty.