Confirmed Fitment
Rock Island MS Magazine Loader
The Rock Island MS is confirmed to fit the Super Thumb ST1 magazine loader from ADCO. The original Super Thumb loads Rock Island MS magazines faster and with far less thumb strain — a purpose-built tool, not a one-size-fits-all compromise.
Your Fit
Super Thumb ST1
Double-Stack
Width
1.29" (32.5 mm)
Height
0.86" (21.9 mm)
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 Rock Island MS. Every Super Thumb is backed by a lifetime warranty.