[1KPerDay]

http://www.youtube.com/watch?v=N0xx7-oS2OA

[Mike J]

1K did you ever get your friends gun figured out?

[1KPerDay]

Nope. I've been working on it for two days. I got it to the point where it won't double feed 49 times out of 50, by adjusting the catch and the tab on the interrupter, but there's another issue and I believe it's with the elevator.

when I put the interrupter and shell catch from the 12 gauge Coast to Coast 880 in the 20 gauge New Haven 600 (which is the one with the issues) it doesn't double feed at all. So obviously something is wrong with either the interrupter or catch or both. With the catch from the 880 and the interrupter from the 600. it will occasionally double feed but isn't as bad as the original combo.

However, the other issue is more problematic: about every 5th or 6th time cycling, the shell will come out of the mag but not be lifted/aligned properly and will nose against the back of the barrel, jamming the gun. You have to return the slide rearward which will occasionally release another shell, making it worse. But I can't tell whether it's the bolt slide not being aggressive enough with the elevator, or the elevator not having the proper grind on its upper inside edges, or the extractors not letting the rim slide up enough, or the bolt face needing to be polished or what. It's very frustrating as it's only occasional. Then it will misfeed like 5 times in a row, then it will be fine for 15 times.

I wish I had another 20 gauge handy to swap parts with. The New haven has the old style bolt/slide lock (without the interlocking cut in the top of the bolt slide and the bottom of the bolt lock, so I'm wondering if that's allowing some play in the bolt or slide that won't let the elevator come up or something.

If I stop and look at the situation when it jams in that way, I can see that the elevator hasn't come up to where it's parallel with the ejector. I can gently move the elevator up with a screwdriver, and that allows the shell to chamber smoothly.

So my gut feeling is a new bolt slide and elevator might fix THAT issue.

This gun has so many issues it's not even funny. And it's been like that since it left the factory. Poor kid got his first shotgun and it's a total lemon. Pity because it's as smooth as butter when it's working. But it's not reliable enough for a chuckar gun, which is what he wants to use it for.

I really wish I could fix it... :(

[chevyforlife21]

how old/beaten up/dirty is this gun?

[1KPerDay]

It's old, but barely shot. New old stock practically. He got it and it didn't work. Sent it back to mossberg twice, they said it was fine. It ain't. He basically put it away for 20 years because he was frustrated with it.

[reckless carolinian]

Almost sounds like its "out of time" with itself. The order of what does what when is jacked up, as evidenced by your earlier statements. If you swap the interrupter and catch, it cures all issues, or does still misalign and jam? If swapping out the interrupter and catch solves all problems, then they are the problems.

[Mike J]

My old 20 gauge only has one action bar but it has the other interrupter than the one you're working on. Good Luck-I hope you can figure it out.

[1KPerDay]

Thanks. I ordered the newer-type interrupter and a new catch just for fun, and a new elevator. Pretty good deal on gunbroker; all three shipped for about $25. And if they don't fix the issue I can keep the interrupter and catch as spares; the elevator was only $5 so if it doesn't work I'm not out much.

Hopefully it's the interrupter and not the bolt slide. The slide/bolt is more expensive. I wonder if going to a new hook-style bolt and bolt slide would fix it.

Reckless, when I swapped the interrupter and catch with his brother's CC880 12 gauge, the doublefeeding issue is cured (and when I put the catch/interruptor from the 20 gauge into the 12, the 12 doublefeeds just like the 20 does), but the elevator/chambering issue remains. Which is more problematic.

I even tried putting in the new-style interrupter from my 590, but it would need some tuning of the catch to make that work properly. It was dropping shells out the bottom when I moved the slide forward. LOL

[reckless carolinian]

Loud & clear, 1k. You got [I]part[I] of the issue with the int and catch. The elevator is "late". Update after all parts installed. Keep posted. This is interesting.

[1KPerDay]

Will do.

[mnrivrat]

You might want to review that video information again.

Although there are two different styles, the older tab style is still actuated by the bolt slide & not by the shell lifter after the bolt is fully rearward. The interuptor has to be actuated before the first round in the magazine clears the tube as to prevent the second round from feeding out past the shell stop.

If the video were correct, the bolt being full rearward before activation, the first round and part of the second round would have cleared the shell stop before the interuptor was activated. This would cause a double feed.

The shell stop is on the other side of the receiver by the way. It holds the shells into the magazine until activated by the ramp on the action bar. This is done early in the rearward motion of the bolt . As the bolt continues to the rear the first shell is pushed into the action by the magazine spring. To prevent the second shell from following it, the interuptor actuates before the front of the first shell clears the throat area of the magazine tube. The interuptor then prevents a double feed by holding the second shell from coming rearward with the first one.

[1KPerDay]

Although there are two different styles, the older tab style is still actuated by the bolt slide & not by the shell lifter after the bolt is fully rearward.

Nope, the horizontal tab is contacted and moved by the elevator. The elevator is moved by the bolt slide, however, so I suppose you could argue that the interrupter is actuated by the bolt slide, technically. But then I guess you could argue that the interrupter is actuated by your hand pumping the action. Which is true.

But the elevator is what pushes the interrupter into position on the older style. If you have one handy take out the trigger group, hold your gun upside down, and have a close look for yourself.

EDIT: Both the old and the new types of interrupters have a vertical, triangularish tab forward of the pivot point; this tab IS contacted by the bolt slide in both the old and the new styles, but it's as the bolt moves forward, moving the interrupter out of the way, or "out of position." So THAT part of the interrutper's travel is activated by the bolt slide, as you say. But the "moving into position" portion, which prevents the release of a second shell as the shell catch releases one, is actuated on the older style by the elevator pressing against the horizontal tab sticking out the side of the older interrupter, and in the newer style by the bolt slide riding up the vertical cam surface/ramp on the newer interrupter.

The interuptor has to be actuated before the first round in the magazine clears the tube as to prevent the second round from feeding out past the shell stop.

That's correct.

If the video were correct, the bolt being full rearward before activation, the first round and part of the second round would have cleared the shell stop before the interuptor was activated. This would cause a double feed.
Correct, but the bolt isn't FULLY rearward. It's close to fully rearward, however (on the old style). There's enough time for the interrupter to move into position before the bolt is all the way back and the action bar presses the shell stop out of the way to release a cartridge. As I said, the new ramped/cammed type moves into position sooner in the cycle, when the bolt is about halfway back. The old style moves into position when the elevator moves, when the bolt is about 95% back.


The shell stop is on the other side of the receiver by the way. It holds the shells into the magazine until activated by the ramp on the action bar. This is done early in the rearward motion of the bolt . As the bolt continues to the rear the first shell is pushed into the action by the magazine spring.

No... it isn't. Again, take a very close look at a mossberg 500/590, which I assume based on the subject of this thread and the video, is the shotgun you're talking about. Move the bolt slowly. The action bar ramp doesn't move the shell catch fully out of the way to release a cartridge until the bolt is nearly fully rearward. If it did it early in the bolt cycle as you claim, the shell would drop out of the loading port onto the ground, because the elevator hasn't moved into position yet (and neither has the cartridge interrupter).

[1KPerDay]

BTW, my buddy reports that he cycled a couple of dozen shells through the gun with no jams or double feeds. So that's good.

He was using Estate loads. I had the occasional elevator jam with Federal (wal-mart) loads, and fewer with Winchester super-X. But I still got the occasional jam of that type.

I'll keep this updated as I receive the new elevator and see if that makes it run with all brands of cartridges.

[1KPerDay]

Well I got it fixed using the original old style interrupter as I said, but I replaced it with a new "new style" interrupter and a new stop. That much works a treat. However a new elevator didn't fix the chambering jam issue. Updated in the original thread here FYI.

I have a new theory... I think it's the extractors.

http://thehighroad.org/showthread.php?p=6183788#post6183788

[1KPerDay]

I was right! Hooray for me! see the update in that other thread. I'm so proud of myself. :D

[Dave McCracken]

Congrats!!

[1KPerDay]

Thank you sir! :cool: