Inerta driven, low power shells provide insuficient inertia to cycle the gun. That being said my SBE II cycles 7/8 high velocity remingtons from walmart. If it really bothers you can buy a lower power spring in the recoil piston tube in the stock, but you will need to switch back for higher power loads or risk damage to the action. My recomendation is to load the gun with higher dram loads in 1 and 2, then put the low power load in 3. This way the jam won't cause any problems.

My SBE II will shoot 1oz loads and eject them, but not reliably. It will eject the 1 1/8oz loads though, which is better than all the other 3.5" guns I have used or heard of.

Wetpowder,
As old as this post is you may have it figured out by now, becauce a few guys already told you "what's up"(Kelbro's post).
As men we sometimes don't need to read directions, but I'm sure somewhere in the manual it talks about using larger loads to "break-in" the action so that your gun can cycle lite loads.
When I first got my Extrema I ran 10 rounds of 3 1/2 inch turkey loads through it as I was pattering it for the season.
I then ran two boxes of 7 1/2 inch high brass through it on the skeet range.
I can now shoot 7/8 oz Wal-mart Federals through it with no problems.
Before you tell me I'm shooting a "gas gun" and the Benelli's are "inertia driven"; try it.

Ditto again. I was going to say the same thing, but I see you guys have beat me too it.

why do you shoot 7/8 loads through a 3.5 gun.???
Also read your manual throughly especially the section on breaking in the gun

Some people can't afford to have a gun especially for shooting light loads. My M2 shoots everything from 7/8 oz dove loads to 2 oz turkey loads. It is the only 12 guage I have, so it has to do everything.

I've shot 10 walmart100 packs or 1000 roundsthrough mine without a problem

I Have one and it shoots and throws whatever u feel like throwing in it i love that gun