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customGaugeMate provides a unique service to the shotgun community. We now make GaugeMate Custom adapters for many odd or obscure gauge-combinations.

If you want to shoot .410s thru your 4-gauge shotgun or have a garage full of 32-g ammo you’d like to use in a 20-g, give us a call at 1-800-709-9910.


One of the first requests came from Silvio Calabi, the Chief Operating Officer for Speedway Illustrated magazine. Silvio was formerly editor of SHOOTING SPORTSMAN magazine and still occasionally contributes articles.

His “problem” was a gorgeous Ferlib ‘Prince’ 24-gauge shotgun. The Italian-made side-by-side boxlock has ejectors, double triggers, 65mm chambers, 27” browned barrels; coin-finished action body, toplever, triggerguard & tang and forend fittings all 100% coverage tight scroll by S. Panteghini. With a straight-grip stock and splinter forend it weighs 5 lbs 5.5 oz. The gun was originally made as part of a nine-gun, consecutively numbered set. When it became part of Silvio’s collection, he wanted to use it – but 24-g cartridges aren’t an item you pick-up at WAL-MART. So he called GaugeMate and asked if we could make 24-g to .410 adapters? No problem.

After using the adapters he sent GaugeMate President Henry Fletcher the following report on April 10, 2006.

“Yesterday I was able to run 100 rounds (AA, 2.5”, half an ounce of #8.5 shot) thru my custom GaugeMates on a sporting clays course, and the results were astonishing.

Shooting ‘against’ five others, also all carrying side-by-sides (i.e., not sick & twisted clay crushers) and all experienced, good to expert shooters, I was able to keep up with the 12-gauges and in some cases outperform them. I was very surprised at how far out I could break clays.

I suspect my Ferlib is tightly choked (as new Italian guns usually are), but intuitively I have a hard time grasping that choke in such an ‘overbored’ tube could much affect the payload. Before you ask: I did not specify the boring of the gun, nor have I patterned it, as things keep falling out of the sky when I point it at them.

The outer walls of the GaugeMates forward of the O-ring got very black. The gun barrels collected considerable grime too, including a distinct trail of what appeared to be unburned powder in the bottom of each tube. However, I got no real sense of any reduction in payload speed. On several long targets there was the usual infinitesimal delay before the impact one experiences with any shotshell, but the breaks were as crisp as usual.

We laughed all day over these tiny cartouches. Good shit, mon!


At the other end of the spectrum, we got the following e-mail concerning our 8 to 12-g adapters.

“What a hoot. These adapters are the greatest. Who else can go to the gun club and shoot a round of skeet or sporting clays with a vintage 8-gauge Parker. The chokes work just fine, giving a tight pattern that smokes the clays. Sunday I will try a round of trap as the pattern is more suited to trap than skeet. Thanks for the fun.”

— Peter, from Cody, Wyoming"

GaugeMate Custom adapters can accomodate a wide variety of barrel and ammo sizes.  GaugeMate Custom adapters are available in both our Premium "stay in the gun" style and our Silver "economy" style.

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See GaugeMate's sub-gauge adapters in action in our Gaugemate Challenge Video
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Learn more: "How Sub-Gauge Adapters Work

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