M197 Three-Barrel Rotary 20mm Cannon

Published: November 7th, 2012     
Detail Packaging
Detail Packaging
Reviewed by: 
Matthew Cottrell, IPMS# 48174
Scale: 1/72
Company: Master Model
Price: $7.50
Product / Stock #: AM-72-038

Weapon History

Developed in the late '60s to replace the M134 7.62mm mini-gun then in use on lightweight helicopter gunships, the M197 20mm 3-barrel rotary cannon is found primarily in the chin mounted turret of later AH-1 Cobras. A derivative of the M61 cannon found on nearly all US fighters since the F-104, the M197 trades 6-barrels and a higher rate of fire for lighter weight and stopping power gained with a 20mm round. The M197 is still in use today on the Cobra, specifically the AH-1W and AH-1Z operated by the USMC.

Kit Contents

More than just an aftermarket part to superglue in place, the Model Master M197 is a very detailed miniature model kit, with extra emphasis on the miniature! The kit is highlighted by three beautifully turned cannon barrels, a small photo etch fret, and an impossibly small bit of brass representing the center nut. My particular kit was packaged with an extra center nut.


Construction of the M197 is fairly straightforward; however, you'll need to be exceptionally steady and precise when handling the small parts -- any errant pressure could launch them deep into the bowels of the carpet monster. The 3 barrels start from a PE disc at the rear of the cannon. I found that using a bit of putty to support the PE disc allowed the barrels to pass through and be held in place while applying CA. Next, the PE support lattice at mid-barrel was easily folded and slipped into place. The hardest part of the build was fitting the barrels through the front, almost clover-shaped, support. It was very difficult to align all three barrels to pass through the openings simultaneously. In the end, I used a small drill bit to enlarge the holes slightly, giving myself a bit more wiggle room. Once the center nut was attached and the glue had dried, it looked great and was still secure even with the slight enlargement.  If I was building this cannon again, I would have left the small clover attached to the fret until after it was mounted, just to allow a bit more control over the part and perhaps avoid having to ream out the holes.


I was very surprised at how much fun I had assembling this little gem of a cannon. Compared to the two-piece injection molded cannon part in the Italeri AH-1W Cobra kit, the difference is astonishing. With the cannon's prominent exterior location, the cost of this aftermarket part is money well spent. It's just the thing to make your Cobra stand out from the crowd.

My thanks to Master Model for the chance to build this rewarding little kit and to IPMS/USA for the chance to review it!

  • Detail parts
    Detail parts
  • Assembled gun
    Assembled gun
  • Comparison with kit part
    Comparison with kit part