[FLBob]

I bought a brand new Mossberg Mariner 590 a few weeks ago. First, I want to thank you all for the wealth of information you share on these forums. I spent a good amount of time browsing and searching the info here.

I took the shotgun out to the range today and shot off a dozen 7 1/2 light target shells from Winchester and everything went as expected. Then I switched to some Federal "Power-Shok" 00 buckshot shells and that's when I ran into problems.

After I fired the first 00 shell, I couldn't rack the pump to eject the shell. I tugged and yanked for almost a minute and finally got it to eject. Thinking (hoping) it was a fluke, I loaded another 00 shell and had the same problem. I went through about 10 of these shells and had to fight to get it to eject every time.

I switched back to more 7 1/2 shells and they cycled through beautifully.

Can anybody explain why this is happening? Or more importantly, how to make it stop?

I have zero experience with firearms until this last month, so your help is greatly appreciated.

Thanks,

 

[mike100]

Your brass on the heavy buckshot loads is expanding and seizing the hull in the chamber. you could try a different lot or brand of high brass buckshot, but maybe, as has been suggested here before, polish the chamber or maybe shoot a few more boxes of low dram birdshot to break it in.

I have seen guns work with one brand, but a cheap one will expand brass and be hard to cycle.

 

[FLBob]

Thanks, I'll try running some more birdshot through it first. Not sure I trust myself to not screw up the barrel by polishing it. I did find a link to a very good, step-by-step polishing proceedure if I end up needing to go that route though.

Next on the list is replacing the bead sight, maybe with a ghost ring - adding a heat shield - and maybe a CompStock. New toys are sooo fun!

 

[jediagh]

I did find a link to a very good, step-by-step polishing proceedure if I end up needing to go that route though.

The link is??? Spread the knowledge of wealth and make our forums even richer.
Thanks