New 870 old shells ejecting problems

[twodko]

Auto loaders

Auto loaders seem to prefer rounds 1300fps or better for consistent
Hull ejection. Especially 20 gauge scatter guns.

[XVIga_Rob]

Nice Job CJ5&G23!!

Not sure what may have been happening with Rem QC. But, I did buy a couple of new 870 express models (from different shops) in the last ~6 months, both have smooth chambers, and no ejection issues.

[jay_cue]

mine had problems with Winchester bulk ammo from Walmart.

[KeepItCal]

Today I cleaned it up. Wrapped a piece of PVC pipe with 400 grit sandpaper to provide uniform sanding pressure to avoid "hills and valleys". All sanding with PVC-wrapped pipe was done by hand - no motors.



400 grit was too smooth, so repeated with 220 grit:



220 works, but would take too long to remove that much material. Used a dremel on the slowest speed to remove most (not all) of the ridges, then back to using the PVC wrapped with 220. Getting close:



Kept at it with 220 until everything was uniform, then went with PVC wrapped with 400:



Then applied bluing (lighting is bad):



Then reassembled. What looks like a horizontal scratch is from me pushing hard on a test shell as I pulled it out of the chamber. No drag now. Note scratch starts where low-base Winchester round's case exits chamber (~ 1/4") which was where tooling marks were bad. A high-base shell would have pulled out of the chamber further before the base exiting the chamber and shifted over.



I'm not a gunsmith, but a home defense shotgun that might hang up on certain ammo had to be fixed, so I did it myself. All in all, came out better than I expected. But, I took my time and did things slowly.

That's a great job! Will follow the steps. My barrel looks just like the second picture. IS bluing necessary after sanding down the area? Will it rust if I dont?

[jeffrice6]

IS bluing necessary after sanding down the area? Will it rust if I dont?

Just keep some oil on it & there shouldn't be an issue. Besides, have you ever seen how well cold blue and the like really hold up?!?

[KeepItCal]

Just keep some oil on it & there shouldn't be an issue. Besides, have you ever seen how well cold blue and the like really hold up?!?

haha thanks j!

[Jimmybacon43]

You guys are all telling him to polish the chamber of his 870 and replace the extractor....

when he said that it was only 20 year old ammo that wouldn't function right and that new factory ammo functioned fine.

Maybe it's the ammo? Anyone think of that?

[kentactic]

Glad my tips worked out well for you CJ5! I drink keystone light

[The Last American Hero]

my 870 Supermag didn't like the cheapest low brass at Walmart(Fed?), but Rem low brass was A-OK at about $1 more per 100rd value pack.

All other high brass, mini-shells(1 3/4"?) were OK.

[KeepItCal]

Update:

870 did have factory tooling marks
-Dremel and sanded it down a bit
-hand sanded with 400grit
-then 600grit
-Dremel with polishing tip and compound
-nice, shiny, and smooth chamber/barrel

Went to shoot trap and after 75 targets it felt great. It didn't jam like before. I wouldn't be able to pull the pump back at all before but didn't have issues now.

New problem though. Around 3 times I had extraction problems. The pump went down no problem but the empty case was still seated in the chamber. So imagine me pulling the pump back(assuming the shell extracted), dropping in a shell into the receiver and pushing the pump forward but it wouldn't go. Then I realized the case was still seated and the extractor wouldn't catch the brass. I tried pushing the pump forward and pulling it back and still wouldn't catch. Ended up eventually pulling the case after multiple controlled pumps.

What do you think is the culprit? Need new extractor? I'm worried this might be a sign that I might of taken too much metal and when the extractor pulls the brass, the shell gets pushed too much and extractor cant engage solidly. Thoughts?

[Jimmy310]

Were you still using Winchester ammo? My shooting buddies 870 express chamber had lots of tool marks and jammed frequently. I did some reading online, then i polished the chamber which helped alot. I polished it some more (only used scotchbrite pads both times) and the ejecting problems were gone. Didn't use winchester shells. The next time we went out we used Winchester shells again and the problems came back. I did a lot of research on the topic and the general consensus says to stay away from Winchester shells. Federal and Remington brand shells are winners!

Update:

870 did have factory tooling marks
-Dremel and sanded it down a bit
-hand sanded with 400grit
-then 600grit
-Dremel with polishing tip and compound
-nice, shiny, and smooth chamber/barrel

Went to shoot trap and after 75 targets it felt great. It didn't jam like before. I wouldn't be able to pull the pump back at all before but didn't have issues now.

New problem though. Around 3 times I had extraction problems. The pump went down no problem but the empty case was still seated in the chamber. So imagine me pulling the pump back(assuming the shell extracted), dropping in a shell into the receiver and pushing the pump forward but it wouldn't go. Then I realized the case was still seated and the extractor wouldn't catch the brass. I tried pushing the pump forward and pulling it back and still wouldn't catch. Ended up eventually pulling the case after multiple controlled pumps.

What do you think is the culprit? Need new extractor? I'm worried this might be a sign that I might of taken too much metal and when the extractor pulls the brass, the shell gets pushed too much and extractor cant engage solidly. Thoughts?

[KeepItCal]

Were you still using Winchester ammo? My shooting buddies 870 express chamber had lots of tool marks and jammed frequently. I did some reading online, then i polished the chamber which helped alot. I polished it some more (only used scotchbrite pads both times) and the ejecting problems were gone. Didn't use winchester shells. The next time we went out we used Winchester shells again and the problems came back. I did a lot of research on the topic and the general consensus says to stay away from Winchester shells. Federal and Remington brand shells are winners!

hmmm yes I was still using Winchester Super X #8 shot. I'll make sure to get a few boxes of something different to see if its any better.

@cj5 I didn't get a chance to try to pull it out with my finger. What I ended up doing was slowly pumping it back and forth until I was able to extract the shell. IF the extractor wasn't getting full bite, is that an extractor issue or is it a chamber issue? (possbily taking too much metal out and when extractor hooks brass, there isn't the same kind of backing to make it a real positive engagement????)

[kentactic]

hmmm yes I was still using Winchester Super X #8 shot. I'll make sure to get a few boxes of something different to see if its any better.

@cj5 I didn't get a chance to try to pull it out with my finger. What I ended up doing was slowly pumping it back and forth until I was able to extract the shell. IF the extractor wasn't getting full bite, is that an extractor issue or is it a chamber issue? (possbily taking too much metal out and when extractor hooks brass, there isn't the same kind of backing to make it a real positive engagement????)

Unless you removed a LOT of material its going to be one of three issues.

1. You need to upgrade to a Non-MIM Extractor due to the current one being out of spec.
2. You need to file more out of the notch for the extractor that is cut into the barrel. If it hits that and cant drop in front of the shells rim then it cant grab it. Be aware that it is normal for it to make contact with that notched area if there is no shell in the chamber so dont go filing it until it dosent. Too much material removed from this area can expose too much shell brass and could be dangerous.
3. Broken/damaged extractor spring and or gummed up area and or the bolt isnt properly cut and its rubbing the extractor bad, causing the extractor to stick up. Pull the action back and test for smooth operation with your finger.

I say do #1 and #3 first. If that doesn't solve it look into #2.

[TRAP55]

20 yr old ammo might affect the cycling of an 1100, but it shouldn't on an 870. I just got through with a headache 870 Express that was locking up as the bolt started to move back. When it wasn't locking up, it still had sticky extraction.
Burnished the chamber, polished the barrel extension, installed a non-MIM extractor and stoned the hook for a 100% contact surface on the hull rim. Huge improvement, but it would still have the occasional lockup.
After lots of cussing and hair pulling, I finally figured it out.
In the pic, you can see a machined groove between the polished area, and the chamber lip. It's recessed deeper than the polished area. The pressure from the extractor was pushing the rim of the hull over into that groove. It was just enough to catch the rim solid, and it wouldn't cycle. Jiggle the pump back and forth, and it would pop loose.

I made a smooth taper from the rear edge of the groove and polished out the groove and the taper to blend into the extension. The cheap crap WalMart aluminum low base bulk ammo was the worse culprit, and even it cycles now.
I compared this barrel with some older Wingmaster barrels, and they they only had a hint of that groove.
Appi, have you run across this before? I would like to hear your input on it!

[kentactic]

^^^^ bingo! Most common cause of sticky extraction is the area DIRECTLY behind the shells rim when chambered.