Mossberg 500 hard to pump to eject shell?

Same answer as the last two times you posted the same question.

Clean the chamber on the short barrel....or loosen the takedown nut and make sure the under barrel flat isn't rubbing on the slide tube collar before you retighten it.

He said before that the gun works fine with the 28" barrel on it so it's not the gun. Mossbergs don't have ammo probs like Remington Express guns do so it's not the ammo. And you can clean and polish the chamber with Scotchbrite pad wrapped around a dowel and chucked in a powerdrill.

First - do not pull back any pressure on the slide while you are shooting. This is the #1 issue with new pump shotgun owners. The shotshell needs a few milliseconds to contract in the chamber before ejecting. When you pull on the pump while shooting it begins to eject the shell as it fires and pump release is triggered - makes the brass 'fat' - and hard to eject.

You should be able to insert a few shells, then pump and cycle them -without firing - very easily. If it does not do this nice and easy - you have simply mis-assembled the gun during cleaning. You need to take it apart and clean it good again - paying attention to any parts that may have bent, been damaged from cycling it assembled wrong.

If after re-assembling it you still have the problem - you have two choices. First is to go buy some 12ga dummy rounds so you can safely cycle and work on this thing. Working on shotguns with live ammo is for idiots and people who like to accidentally kill themselves, friends, neighbors, wives, or children. Then go visit a store and cycle an identical model - and look closesly at how it is assembled. Read the manual - an try again.

If the above does not work - you need to drop it off at a gunsmith for a safety check. Might cost you $75 - but - it will be money well spent.

Trouble shooting step number 1: Clean the weapon, especially the chamber, and oil as recommended

Trouble shooting step number 2: Try a different load (brand of ammo)

Trouble shooting step number 3: "Polish" the chamber by wrapping masking tape around an empty hull and spinning it in the chamber on an electric drill. Two or three layers of masking tape for proper thickness.

In general, stuck cases are caused by excessive obturation of the hull (case stretch), or by a dirty chamber. Mechanically, it also could be caused by the action failing to "unlock" due to build up in the action.

Excessive obturation can also occur because you have a tight fitting chamber, so ANY stretch is too much stretch. Certain brands of hulls will stretch more than others, so simply switching over to a different brand may solve your problem (I have a .410 shotgun that will not extract Federal ammo, so if I ever fire Federal ammo in that weapon, I will have to drive the empty out with a cleaning rod. The weapon functions flawlessly with any other brand).

Polishing the chambers might also help. A flex-hone kit and honing compound is the best option, however, it's pretty expensive. The "cheap" option is to use an electric power drill, a spent case, and some masking tape. Drill out the primer of a spent case, stick a 1 1/2" to 2" small bolt through the hole from the INSIDE of the case, and tighten a nut on the bolt from the outside. Re-fold the crimp of the shell back closed as best you can. Wrap the shell carefully with 2-3 layers of masking tape (this is your abrasive media). Chuck the end of the bolt into the power drill. Remove your barrel from your shotgun. (If the barrel is threaded into the receiver, then don't remove it, simply use a longer bolt, or piece of "all-thread"). Spin the wrapped hull in the chamber of the barrel using the power drill for a few minutes. Have a spare empty hull on hand. When the chambers are properly polished, the spare empty should go into, and fall out of, the chamber very easily.

Sounds to me like the chamber is dirty. You aren't using hand loads, are you? If so, they may be overpressure. Scrub the chamber real well. You may want to take a 12 ga brush and holding it so that it will not rotate, move it around in your chamber. Make sure that you clean all the way to the far end of the chamber. After you think the chamber is clean, make sure that there are no pits or bumps in the chamber. Also check the lugs on the barrel and bolt and make sure that they are clean and not damaged. I am not familiar with the Mossberg 500. It if has a rotary bolt, make sure that it rotates freely.

My first suggestion would be to try different shells. My 870 is like that with certain cheap loads. My second guess is a lot less likely since it's a fairly new gun. It is possible that there is a one or more tiny cracks inside the chamber, when you shoot the shell expands to fill those tiny cracks thus making it hard to eject. You can always take it to a competent gunsmith and have them check it out for you so you're not just guessing. Hope this helps.

Before you do anything else completely disassemble said shotgun and clean it, use oil sparingly and blow it with compressed air, then put it back together. Still have problems check out your ammo and make sure you are not using something you shouldn't.

1. be sure you are holding the pump FORWARD, not BACK, when shooting. (THIS keeps the action from "unlocking" when fired.)

2. be sure you are using the CORRECT ammunition. (the correct LENGTH is IMPORTANT.)

3. clean and lubricate correctly. (Oil is a POOR lubricant, under cold conditions, and also attracts dirt which can "clog up" the working parts.)

try different shells. make sure its well lubed and well maintained