Kinda looks like you are having a failure to extract and eject.
How does the extractor look? Does it grab the rim of the hull good? Is the spring good, have plenty of tension?
How about the chamber?
You might try taking a bore brush and a short section of cleaning rod, chuck it up in a drill...
I prefer the 20 inch over a 18.5 any day.
In my opinion, you gain nothing dropping down to 18.5 except for reduced capacity.
I will take the extra capacity.
You got a really good deal at that price!
Apparently my prices are too high. I based them off what I saw others sell for.
Lets try $200 for the scoped barrel and $150 for the rifle sight barrel.
I have two Mossberg 500 or maverick 88 fully rifled barrels. Both are 24 inches long.
The upper one has a cantilever scope mount and has a bushnell sportview 1.5-4.5 scope on it. This barrel is used with only just a few light handing marks here and there. Bore looks perfect.
The next barrel is...
I had the barrel on my 930SPX threaded for chokes.
Probably the best thing I did to it. I can now swap out the chokes to whatever I want.
I currently have a extended "breacher" choke on it with a longer mag tube to match the extra length.
I had Steve Rose of Rose action sports thread my...
I have a good used Mossberg 930 SPX. Has a few light scratches and marks here and there, but mechanically is it perfectly fine.
18.5 inch cylinder bore barrel 7+1 mag tube.
It has cycled everything I have shot through it. Buckshot, slugs, birdshot, and even the federal 100 round value packs of...
It is usually not needed after every time you shoot it.
I will take mine out and clean it every few cleanings.
If it is brand new, taking it out for a cleaning and light lube it not a bad idea.
One thing I have learned about mossberg shotguns, is they are some of the best and most reliable, but have some of the worst resale valves of any gun I have seen.
Does not matter if they are beat to hell, or like new in box. Seems like no one wants to give anything for them secondhand.
Not to...
You could always buy a whole nother gun with the 28 inch barrel already on it.
Seems replacement 930 barrels are a thing of the past.
https://www.gunbroker.com/item/955695571
That seller is only about a hour away from me.
I would be tempted if I could find another barrel to put back on the...