CZ 920 failure to extract/ eject

[britlab]

I have a CZ 920 shotgun that when it works is great but at times fails to fully extract or eject shells. Problem was infrequent at first but has gotten worse. After cleaning can shoot a half a box to a box of shells then it malfunctions.
called CZ they said to try different shells, I explained that problem occurs with Kent, Federal, and Winchester shells. Then they told me I was shooting shells with too light of load, I replied that Kents were 3" mag waterfowl loads at 1550 fps told me I needed to find heavier loads. CZ finally agreed to warranty the gun got it back after a month with a note that gun functioned normally. I took it to the trap range failed to fully extract or eject shells 14 times in 2 rounds of trap. Called CZ they want me to send it back again, called Davidson they are sending a new shotgun to the dealer hopefully it is more reliable than the first one.

[HighWildFree]

What type of ammo - oz of shot? My 912 hates Winchester but blasts federal.

[britlab]

as stated Kent, federal and Winchester 23/4' and 3" steel and lead shot

[HighWildFree]

What I meant was how heavy a load? 1oz, 3/4 oz? You say you shot clays yesterday; what shells and what weight?

[britlab]

Winchester AA sporting clays 7/8 oz at 1275 fps. Problem is not with the ammo shotgun wont run reliably with any premium ammo

[jrpowell3]

I've found that typically semi-auto shotguns prefer the heavier loads. 7/8oz is kinda light.

[britlab]

So the kent 3" mag waterfowl loads at 1550fps too light also? This is a 20 ga 7/8 oz is the standard load and work fine in my friends 1100

[Steve_In_29]

I've found that typically semi-auto shotguns prefer the heavier loads. 7/8oz is kinda light.

Both of my Escort semi-autos (one 12G/one 20G) cycle the cheap Walmart bulk just fine, as does my ATI 12G semi.