870 supermag ejection problem

[FXDWG]

Good evening guys this is my first post on this forum. I bought a turkey/ predator SPS supermag last year. It cycles 3 1/2" and 3" just fine. When I attempt to use 2 3/4 target loads, every second or third round gets stuck. The empty shell gets lodged in the chamber at the end of the barrel. The slide locks forward. I have had to tap the spent round out by putting a rod down the end of the barrel and tapping with a hammer (of corse the gun is verified as empty first). Will polishing the inside of the chamber stop the shells from getting stuck? BTW, this thing is hell on turkeys with heavy blend and a rhino .660. I miscalculated range and flattened one at 65 yds (marked a palmetto at 45 then lined up the wrong palmetto). Thank you in advance for any advise you may have. 

[duckaholic25]

I'm having the same problem with the same gun

[nyhunter]

are you asking if polishing the chamber will remedy the problem ? I'm assuming you thinking is to smooth up are so the shell doesnt "hang up"! That may help yes. did you try other brands of shells? Are the 2 3/4 a low base "shorter brass" shell ?

[knightrider]

Good evening guys this is my first post on this forum. I bought a turkey/ predator SPS supermag last year. It cycles 3 1/2" and 3" just fine. When I attempt to use 2 3/4 target loads, every second or third round gets stuck. The empty shell gets lodged in the chamber at the end of the barrel. The slide locks forward. I have had to tap the spent round out by putting a rod down the end of the barrel and tapping with a hammer (of corse the gun is verified as empty first). Will polishing the inside of the chamber stop the shells from getting stuck? BTW, this thing is hell on turkeys with heavy blend and a rhino .660. I miscalculated range and flattened one at 65 yds (marked a palmetto at 45 then lined up the wrong palmetto). Thank you in advance for any advise you may have. 

welcome to the sight and polising in this case i dont belive would help your problem? i would email rem and see if they have a suggestion as it seems others have had this problem, and please refrain from talking of any kills over 40 yards as it is site rules. once again welcome and enjoy

[Cajun1]

Hi FXDWG and  This is actually not an uncommon problem with some of the 870 express's.  I had two that did the same thing.  This is caused by a couple of issues.  1st, the cheap low brass shells could be a problem.  The brass (now usually thin steel) is so thin that upon firing the shell the brass expands and sticks the shell in the chamber. (especially the cheap winchester 100 pack)  A few guys I know used a brake cylinder hone and smoothed out the chamber of their 870's or a bore brush with steel wool and it has seemed to remedy the problem.  The 2nd issue with the 870's is that they have a single extractor which is on the outside of the bolt.  When the shell is pulled from the chamber with extractor the shell has a tendency to twist or rock toward the back side of the receiver.  Let me see if I can explain this where it can be understood.  Remove the barrel from your gun and look at the smooth part of the barrel just before the chamber where the bolt and barrel fit together.  (Will be the part at the back of the receiver directly opposite the extractor) Feel of this area with your finger.  On some of the 870's the machining is a little off and there is a little hump there.  You might not even be able to see it but you can feel it.  When the bolt is pulled back the shell twists and the rim of the shell opposite the extractor hangs behind this little hump locking the slide up. Take a look at both of these issues, one of them is likely your problem.  If its the second, a dremel with a small grinding wheel can take care of that.  Just be careful to only remove the raised part that is causing the problem. From what you've stated I'm thinking it may just be the cheap shells but I'd take a look at both scenarios to make sure.

Cajun1

[benellinut]

Im having the same problem with a 870 supermag i bought my boy for christmas.Fired shell gets stuck in the barrel and it does not matter what kind or length shell it is.Sent it back to remington and it was gone 2 weeks when i got the gun back they said it had a rough spot in the chamber and it was fixed.So i took gun out same day i got it back and shot it and guess what first 3 1/2 shell gets stuck in barrel really so after taking cleaning rod and knocking it out i shot a 3 inch shell guess what same thing so i call them and they say send it back.so now it is back there again i asked for my money back or new gun and guy i talked to got really rude after i said that.I said well you did not fix it on the first time so why do you think this time is any different.I did a google search and this is a common problem going on with the supermag.I Thought about trying to polish it but it is under warranty and if i mess with it and still have trouble I'm screwed.so it is back setting at remington.when i get it back or different gun it is gone that day and a new benell supernova will take its place.Im done with remington and there rude costumer service.GOOD LUCK!!!!!

[WildSpur]

Man I must be lucky.   My supermag was made in 2012 and I have not had any problems.

Sent from my SCH-I545 using Tapatalk

[bunk]

Mine was made in late 90's and would hang bad at first but got better over time. Never really botherd me until I started turkey hunting and taking the same shells in and out over and over. It would bur up the rem of the shell and dent the side of the brass. I took it to a good gun smith thinking the chamber needed honed out but he said it was the groove in the chamber where the rem of the shell set was not cut deep enough from the factory. He fixed it and it is smooth as butter with any shell. Just slides open easy.

[Cajun1]

Not going to say all of them are this way but I had two supermags  that did this. Neither do I own anymore. This is one of the reasons I stuck with Mossberg.
Hope you can get it resolved.


Sent from my Mossberg 835.

[Cajun1]

http://youtu.be/mlGoxNsaieE

This link will show exactly what I'm talking about above.


Sent from my Mossberg 835.

[FXDWG]

Thank you for the replies. When I get back to my camp, I'll look at it. It is encouraging that it may be easily repaired. I love the gun, other than the 2 3/4 hang up. I apologize about the long shot statement as stated it was a misjudged range. I really prefer them up close and wouldn't intentionally take a long shot. Thank you for the warm welcome. I really enjoy the forum and learn a lot from the posts. I'll check back in and post the outcome. Thank you Cajun

[FXDWG]

Thank you for the video Cajun. It was perfectly clear. I found the machining defect exactly as discribed in the video. I followed the procedure and now it's gone. I will test it and post results. It couldn't have been easier. 

[Cajun1]

You're welcome FXDWG! I really hope that takes care of it. I don't mean to be an 870 basher, as I stated earlier, it just seems that Remington's QC has fallen off in the last few years. I know they can be great guns if someone has the patience to figure out the issues and fix them. I've got buddies that shoot them and love them. Look forward to hearing if that solved the problem!


Sent from my Mossberg 835.

[Assault]

I had an issue also, I ordered a new spring (can't remember technical term) for the extractor claw that pulls the casing out, also polished the chamber in barrel. No issues any more! I can shoot the cheap federal and Winchester with no issues


If its up high, it's coming to the ground

[FXDWG]

I have a range update- I followed the you-tube video posted by Cajun. Afterword I looked at my old 870 that has never given an issue. The old gun had no ridge from sloppy machine work. I removed the ridge on the new gun as discribed in the video. The supermag now runs perfectly. Thank you once again Cajun. I recommend this for anyone with supermag ejection problems. It takes longer to put the bits in the dremell than the actual repair. It couldn't have been easier. Four weeks and it's on