Not sporting but a 20 gauge Montefeltro with 26" barrel. Have used it exclusively since I purchased it in 2003. Used for doves for first season every day for 10 days in September. Then on to quail. Season is approx second week of October to first week of February. Have put several thousand rounds though it. Very reliable.
There are a few things worth mentioning. The bolt handle can sometimes catch on brush which can move the bolt with its rotary head rearwards ever so slightly. It is enough to prevent the shotgun from firing. If the trigger is pulled the gun won't fire there will just be a click followed by a shell coming out of the magazine. Should this happen while shooting at a bird, pull bolt rearward and let it snap shut. It will eject round in chamber and the one that came out will be chambered and you can shoot. As a result of this occasional issue I am in the habit of occasionally pulling the bolt back a bit and letting it snap it back into full battery while hunting. This issue still gets me once or twice a year while hunting mearns quail in thick cover.
I keep four shells in the magazine for quail season, emptying gun after a hunt. Even so after a few years I noticed that sometimes the last shell wouldn't always leave the magazine with enough speed to place it in correct position for the bolt to pick it up. The issue is the hollow plastic piece that rides in the magazine tube will get dirty. In addition the spring began to loose its full pressure. Solution is to at least once a season to unscrew magazine tube and clean inside as well as plastic piece AND stretch the spring.
While cleaning isn't necessary for an entire dove season with 25 boxes or so fired, sometimes a basic cleaning and light oiling of bolt and adjoining pieces will help with fast cycling.
I have found the supplied chokes to perform a bit tighter than their name might imply. To date I only tried the modified once. I use improved for dove and gambels quail and can hit them at some very long distances with 1 oz field loads of 7 1/2. Cylinder choke is used for mearns with 1 oz of #8s. Have dropped many mearns as far as 35-40 yds. (of course mearns are easily dropped with a single pellet)
A friend has an Ethos in 20 gauge. That shotgun doesn't have the issue with the bolt getting out of battery but I recently looked at a new montefeltro and it still has this issue.
Hope this helps.
