This from a previous discussion:
Inserts were reviewed in the March/April 06' Shooting Sportsman. I've used the
Browning Little Skeeters-simple tube/sleeve to slide the smaller shell into. They were messy with powder blow back into the receiver and even AAs or STSs will eventually get stuck, and Estates and others will stick the first time. The
Gauge-Mate Tubes are similar but have a little cut out to help remove the spent shell. Both might work ONCE in a repeater but if you don't catch the spent tube it's going to get dinged pretty bad if it hits the concrete pad.
The
Chamber Mates and the
GaugeMate-Golds http://www.gauge-mate.com/steves_corner.htm both stay in the gun by rubber O-rings. The
Chamber Mates have integral extractors and the
GaugeMate-Golds have a larger cut our so the extractor of the gun should work. However, the O-rings did not hold up well.
Most testers, and I agree, got good patterns esp. if going down only a gauge or two: 12 to 20 or 16 to 28, but some patterned well even 12 to .410.
Advertised cost:
Gauge-Mate Tubes $40,
GaugeMate-Gold $130-150,
Chamber Mates $240. I think my
Brownings were $50 and I'm not sure they're still offered.
Bottom line-dirty and kind of a pain but they pattern surprisingly well and pressure testing show significantly lower pressures. I can post that data if desired.
