My Nova won't cycle the last shell from the tube when I'm shooting 3" or 3.5" shells. Do you guys think the tube could be dirty, or the magazine tube spring could be weak? That's about all I can think of being the issue. It screwed me a couple of times on a hunt in AR this year and I don't want it to happen again.

Could be either or both of those issues.. When was the last time you stripped it down for a good cleaning?

To be clear - are you saying the last shell will not even come OUT of the magazine?

It won't come fully out of the magazine. 3.5" shell stay about half way in.

What's the best way to try and clean it?

As mentioned before, there are two easy/cheap things that will most likely fix the problem; clean the magazine tube and replace the magazine tube spring. The latter are less than $15 bucks.

You can take it to a professional gunsmith and have him do it. He will probably charge you $50-$75 bucks.

Or, you can do it. Go to Youtube and search: Benelli Nova disassembly cleaning. Or 'Benelli Nova magazine tube spring replacement' You should be able to find four or five videos on the subject.

Watch a couple and deem who knows what they are talking and does a good job demonstrating. Here's a clue on figuring out who is most competent; look at the tools they are using. If they utilize a claw hammer and a 69 cent screwdriver that doubles as a paint can lid remover...that's NOT the one.

Take your time and it's actually pretty easy. If you have to pry a spring retainer out of the tube (like the Remington system) be careful! Because spring pressure will launch that thing somewhere hard to find.

As for cleaning the tube once the spring and follower are out just clean it like you would a shotgun barrel; some solvent, some patches, real light oiling. If there is any built up crud perhaps a bore brush. Then put it back together. Safely function test it to see if your new spring does the trick.

Note on replacement magazine springs. There might be a specific one that Benelli sells for that gun. Otherwise you might get a 'Universal' spring that works in most all 12 gauge tube magazine tube guns. Sometimes they can be a bit long and might need trimming a bit if you intend to get all the shells in you think you might need without breaking your thumb pushing them in. Clip a a coil or two off and try it again till you get it right.

My Dad had a 16 gauge Ithaca that he kept fully loaded next to his bed for 40+ years. When I got it the magazine spring was weakened from being compressed many years and would not push the shells out just like you described.

Check Wolff springs for replacements. If they carry them for the NOVA series, they will be good ones at a good price.