Thread: 870 express supermag

Get a can of Break free spray the inside of the receiver should help. Jim C.

I have had the same issue in my 870 with kent 3 and a halfs, but it doesn't happen all the time. Kent's are cheap shells. (not price wise....these days nothing is cheap) I had one with a little corrosion on the brass blow out the side one time. Pulled the trigger on a pair of fast moving woodies and the pump kicked back on me and something didn't sound right. Got to looking around the blind and realized I had peppered the blind and the shell had a pretty good hole where the brass meets the plastic. I was glad that I was hunting alone that day. That's the only brand of shell I have ever had this happen with. Having said all of that, I still shoot them. They pattern best and are usually a bit cheaper then other brands.
Chris

Remington's like Remington shells the best is what I have learned over the years.

I wonder if the brass is expanding after the shot and causing the shell to stick in the chamber for a second or two (until the brass cools down and contracts). The Kent brass may be more prone to swelling if it's thinner than other brands.

First thing that comes to mind for me would be to polish the chamber on the barrel. I use a 20ga. copper brush wrapped in steel wool (and I apply a small amount of polishing compound) to polish a 12ga. chamber. I put one section of the cleaning rod in a cordless drill and use that to do the polishing. It only takes about 10 minutes and you probably wouldn't have to use a polishing compound to get good results.

I had a similar problem with dove loads (don't remember brand off hand) in a Remington 1100 and polishing the chamber fixed it. Good luck and I hope you get it figured out. I use a Remington 870 Supermag for all my waterfowl, turkey and deer hunting and they are darned near bulletproof in my opinion.

Well it can be several things. One: cleanliness,,... although you said you been there, done that. Now measure a shell before it is shot and then after(let a professional do the firing!) for the length. Make sure you have the right length of ammo for this gun, e.i. 2&3/4", 3", 31/2 inch. OK? What is the length of one of the FIRED shells? The "2 and 3/4 length", i.e.,3", 3 and a half INCH,,... IS measured from the FIRED LENGTH not the UNFIRED LENGTH!*****
There could be a headspace problem CAUSING the --*extreme high pressure*--!!!. With an unfired round put a piece of masking tape on the back of the round. (over the primer and the base of the round, then chamber it and see if it will close. If it does, then put another piece over the top of that one. It should not take very many pieces of tape until the bolt WON"T close on the round! Measure with calipers the tape and add them up. That will tell you the head space amount,,... as a FIRST TEST WAY to tell or not about headspace. A PROFESSIONAL will have headspace gauges!!! I can not recall the amount of headspace that your paticular gun should have +/-,,...has, but there is a SAFE number and I beg you to find out before YOU fire any more rounds!!! Does any other ammo do this kind of "stuff",,... ( excessive pressure signs)? If not, it's in that ammo! We automatically assume that all ammo is correct in sizes,,...but!!! You are having HIGH PRESSURE SIGNS!!!!!!! This IS DANGEROUS!!!!!! If your gun has headspace problems then it MUST be corrected! What is your gun chambered for? 2and 3/4 or 3" or what? What is the fired length of a round of that ammo. Have a professional do the firing and discuss the length and see what he thinks! CHECK the sides of a fired shell and the brass, are there any cracks anywhere? IF THAT GUN BLOWS IT COULD POSSIBLY TAKE THE SIDE OF YOUR HEAD OFF AND COULD TAKE YOUR BRAIN WITH IT!!! PLEASE BE CAREFUL!!! What you have described is too much headspace and/or too high of pressure! Let me/us know, OK?

OK I just re-read your first post where you said that your gun does NOT hang the shell in the chamber with other ammo and "this stuff" does,,... causing you to pump it hard, back up to the stuck shell,,... to remove it,,... and you have cleaned it. OK. This is in the ammo it's self! Has to be!~ do some checking. Like I said we assume that all ammo is made correctly but in all reality is everything always correctly made? Check those shells! Go over them with a fine tooth comb in and out and if no answer then, turn that ammo over to the police or fire dept to get rid of it and go on and use your gun,,... just not any more with that brand of shells!
That is dangerous pressure signs,,... with what you wrote! Check with a pro! Retired (25years),,... gun mechanic. Be careful. Good luck!

The fired hulls on Kents are longer than most others. Several autoloaders won't feed them correctly. I've never had an issue and have shot no telling how many cases of the stuff but I know people who have.

That being said, for a spell the 870's had chambers that were as rough as a corn cob straight from the factory. Hitting them lightly with a hone smooths them right up.

Originally Posted by Bytizawn

OK I just re-read your first post where you said that your gun does NOT hang the shell in the chamber with other ammo and "this stuff" does,,... causing you to pump it hard, back up to the stuck shell,,... to remove it,,... and you have cleaned it. OK. This is in the ammo it's self! Has to be!~ do some checking. Like I said we assume that all ammo is made correctly but in all reality is everything always correctly made? Check those shells! Go over them with a fine tooth comb in and out and if no answer then, turn that ammo over to the police or fire dept to get rid of it and go on and use your gun,,... just not any more with that brand of shells!
That is dangerous pressure signs,,... with what you wrote! Check with a pro! Retired (25years),,... gun mechanic. Be careful. Good luck!

bytizawn the gun i chambered for 2 3/4 3 and 3 1/2 inch shells. i have cleaned the gun and decided i would take the extractor out and do a good cleaning on it also and i went and shot the gun this past sunday and shot the kent 3 inch shells and only one jammed out of about 15 shells. i think the spring in the extractor maybe getting weak after years of use. thanks for all your help i will keep it in mind.
tader