recommendations to increase 930 reliability

[Thecelt]

im curious to know if there are fairly simple ways to increase the reliability of the 930 that dont require sending it out to a gunsmith. i replaced the stock follower with a gg&g because when attempting to insert the first round (when using rio royal with a deep crimp) it would get wedged between the front of the loading port, and hang up on the top lip of the stock follower. changing the follower got rid of the issue. i know i could send it out for the royal treatment to a well known smith but frankly thats not in the budget for right now. so im looking for simple things i could do to increase reliability.

yesterday i put 100 rounds of remington 7.5 shot, 3 1/4 dram, 1290fps game loads through my jm. this only makes a total of 180 rounds down the tube so far. i have had 3 malfunctions in the first 180 rounds. i know everyone says that the 930's need a breakin period because they come a little "rough" from the factory which is understandable at the price point.

It had one failure to eject but this could be ammo related. I grabbed some old boxes of fiocchi that my lgs had on the shelf. It almost seemed as if the spent shell was too long. I pulled the bolt all the way back but the front of the shell could not get out of the ejection port. A quick grab with my leather man pulled it out.

The second was a double feed. The second shell got stuck on the lifter when going to feed so two shells came out of the mag tube at once.

and the third was in yesterdays batch of 100 about half way through the box. after about 3 shots the bolt locked back with a shell on the lifter, but it did not go into battery. i fiddled with it, quickly got it loaded and then it worked flawlessly for the rest of the box. i read the other thread about polishing the shell stop so I will look to do that, but what else could i polish up to help smooth things out? im quite mechanically inclined but i have done very little "gunsmithing" work and i dont want to screw something up. so any pointers, pictures, or explanations would be appreciated.