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Mossberg 464 Lever Action Troubleshooting

Discussion in 'Mossberg 464 Lever Action' started by DHonovich, Sep 3, 2010.

  1. CaddmannQ

    CaddmannQ 12g Supporter

    Messages:
    7,430
    OK i fixed the whole thing by polishing the bolt and rails with scotchbrite. See my post in the 464 review thread.
  2. CaddmannQ

    CaddmannQ 12g Supporter

    Messages:
    7,430
    WTH, here's some pics of the trouble areas:

    This gun is beautiful and does draw attention. It's accurate for a carbine too, and feels very solid when you shoot it. It's well balanced too. Mine is the Davidson's special .30-30 Brush Gun (I call it a bush gun.)

    It has a matt-finish high-tech heatproof electrostatic-aluminized coating that looks slightly better than cheap aluminum paint and works somewhat better. Some places inside the receiver the finish was thick, and some places it was rough, like it was shot on too cold.

    You can see where the finish was wearing heavily on top of the bolt. this pic was actually taken after polishing the bolt, but after shooting 70 rounds, it looked pretty much like that. Heavy wear right at the middle, which is the spot rubbing the underside of the bridge.

    DSCF8828.JPG

    The bolt was like that--Like metallic lacquer paint that hasn't been rubbed out. It's smooth as silk now. I also had to file some rough bits on the grip safety tangs (grip safety action was catching), and the high corner of the hammer.

    After pulling the bolt I ran a brass shotgun brush up the rails, then scotchbrite. I polished the snot out of the rails and bolt with scotchbrite. Also the underside of the "bridge"

    Anyhow, the process was easy if you know what 2 screws and 2 pins to remove. The pins come out easily & go in with one light tap, once you get the lever aligned in the bolt. The two screws simply lock the lever hinge pin and floor plate hinge pin in place.

    The action is so much better you wouldn't believe it was the same gun.

    Disassembly to this point was all that was necessary. I didn't need to pull the trigger, elevator, or cartridge guide rails.

    DSCF8814.JPG

    The edges of the "bridge" are very sharp and digging into the coating on the bolt. I polished them down with white scotchbrite.

    DSCF8830.JPG
    Polish these edges, front & rear of the bridge:
    DSCF8823.JPG

    Wear pattern underside of the bolt was heavy because the hammer was a few thousandths taller on that side.

    DSCF8812.JPG
    This caused a lot of drag on the bolt, which coupled with the rough bolt finish and sharp bridge edges threw off the timing.

    The bolt moved too slowly and the breech lock was hitting it on the flat instead of on the bevel, causing the bolt to press hard on the sharp edges of the bridge. They dug into the Marinecote and instant hang!


    This action was so beautiful and well-priced, yet disappointing and balky right out of the box. And just got worse and worse as the parts dug into the finish. I nearly sent it back for a refund and bought a Browning or a Marlin.

    Now it moves as slick as a whistle, and fellas I'm in love again! :)
    John A. likes this.
  3. CaddmannQ

    CaddmannQ 12g Supporter

    Messages:
    7,430
    I've found the this gun does not like the Fusion rounds, but seems to like the American Whitetails and the Winchester 170s. The Lever Revolutions shot very well too, but much more costly. The Fusions and the Remington Core-Loks seemed to hang on the feed tube a little, and would jam hard if you tried to cycle the action too fast.

    The Hornaday Whitetails cycled really well, and I didn't have a single missfeed in 30 rounds.

    I'm no good shooting without a scope though. With open sights at 100 yards a 7" pattern was the best I could shoot with 6 rounds. Elevations were actually pretty consistent, but windage was all over. That's me though. I'm a shaky old man with cataracts. The gun will certainly shoot better than I do.
  4. Oak Valley shooter

    Oak Valley shooter .410

    Messages:
    36
    Try shooting with fingers around lever instead of thru it for abetter squeeze. Let us know if it works
    sullivan likes this.
  5. CaddmannQ

    CaddmannQ 12g Supporter

    Messages:
    7,430
    I saw the trigger stop was rough, like stamped from a worn die, and so I dressed it down smooth where it kisses the back of the trigger.
    Not too much or the safety won't work!

    I also dressed it smooth where it rides on the lever.
    Same caution applies!
    If you file it too much, take the safety out & replace it.

    If you can pressure the trigger and then just kinda jiggle the gun without touching the lever & thus defeat the grip safety & fire, it's too short.

    This is the first part I would like to re-make for this gun, & I'll grind it from solid stock & hand file it. It doesn't have to match, but it does have to work better than OEM. The stamped safety is a huge small wart on an otherwise pretty nicely finished rifle.
    Last edited: Nov 27, 2015
  6. ko4nrbs

    ko4nrbs .410

    Messages:
    50
    Thanks for the detailed information. I may try this with mine to see if it helps with the feeding.
    Bill
  7. Oak Valley shooter

    Oak Valley shooter .410

    Messages:
    36
    T
    try wrapping hand around lever to squeeze instead of through when firing, has it been cleaned good?
  8. CaddmannQ

    CaddmannQ 12g Supporter

    Messages:
    7,430
    I had a couple instances this week where the gun locked after firing or after just charging.

    I think it was related to the length of the cartridges. I measured a big variation in length across all 6 brands I had.

    I say "big" being unaware of the real specs on ammo dimensions. I just judge based on what I know of machine tools and such.

    Someone else does my re-loading & I am not familliar with the specifics, but I will be testing different lengths now.

    I posted more info in the "464 locks after firing" thread.
  9. CaddmannQ

    CaddmannQ 12g Supporter

    Messages:
    7,430
    I have been threatening to shorten the mainspring on my 464 for some time, as it has too much pressure from the hammer to the bolt when cycled.

    I finally did it tonight, but not by cutting. See that zig-zag bit of stamped steel on which the mainspring rides, and which connects it to the hammer?
    20160124_231057-1.jpg

    20160124_231013-1.jpg
    I bent it to make it shorter, which only required the buttstock to be removed, & 2 pair of stout pliers the correct shape.

    I took apart nothing else. I did push the spring back to get pliers on the link. I bent the approx. 90° angle, right at the spring, a bit tighter. (It does not look quite like a 90° in my crooked photo...)

    I don't have before-and-after pics, but the bend required is so slight you wouldn't easily notice.

    You would notice reduced lever effort, and the hammer still strikes with authority.
    Last edited: Jan 25, 2016
  10. Oak Valley shooter

    Oak Valley shooter .410

    Messages:
    36
    I
    have a 2008 model 464 and have never had a problem except day i traded for it. Someone turned the magazine spring cup around backwards. I also recommend gun grease on innards as long as you stay away from the bore. Youtube is usually got good repair videos.
  11. Oak Valley shooter

    Oak Valley shooter .410

    Messages:
    36
    My new marlin had a problem with reloads that were a tad longer
  12. CaddmannQ

    CaddmannQ 12g Supporter

    Messages:
    7,430
    I've seen this reported before. The new ones are orange, so kinda hard to reverse them and not know.

    I have once disassembled the feed tube on this gun. It was OK, but after my experience with the Henrys I was looking into it, mostly for rust.
  13. CaddmannQ

    CaddmannQ 12g Supporter

    Messages:
    7,430
    The Mossberg doesn't like them too long, and the Henry doesn't like them too short. They're like women and skirts.
  14. Oak Valley shooter

    Oak Valley shooter .410

    Messages:
    36
    The orange cup is probably not your problem just wanted to mention it. Ive never had to take mine apart so i cant hel you. I have an old 472 mossy that ate my lunch finally fixed it. If you can pull it apart partially and put pieces together out of the housing and actuate it and watch closely this may help but sounds like ammo
  15. Frgood

    Frgood .410

    Messages:
    69
    I was nervous removing the stock, vis-a-vis the warranty, But based on the pictures above, I think it worth while to see if I can diagnose my issue with the lock-up (getting stuck) occasionally after firing. To resolve I push down on the Cross-block (bolt?) safety and that seems to release whatever is preventing the action.

    Mind you I have two 464 SPXs and my first one has zero issues. The ZMB version bought last year, new, has this occasional lock-up. I was hoping it might merely be simply a break-in issue as It does seem to occurs less frequently as I continue to use it. This thread discussion of manufacturing burrs seems to pop up on occasion and does not reduce my faith in the product.

    Thanks all for the heads up.
  16. CaddmannQ

    CaddmannQ 12g Supporter

    Messages:
    7,430
    Mine had rough machining on the surface of the trap door (or "link" as Mossberg calls it) which pushes the lock up behind the bolt.

    I dressed that down a little and now the lock doesn't come up quite so high or as soon.

    I probably only took off about 0.005" with a small file.

    This prevents the lock from hitting the underside of the bolt so soon, before it is forward enough.

    I think the lockups are basically 3 problems causing one symptom.

    1. Ammo too long.
    2. Lock rising too soon.
    3.Scraping friction removes lube because the mainspring is too tight.
    Frgood likes this.
  17. CaddmannQ

    CaddmannQ 12g Supporter

    Messages:
    7,430
    To reduce the scraping friction, I reduced the main spring pressure by bending the mainspring link. It worked, and the gun still fired, so I reduced it about as much as I can by just bending the link.

    I won't know if it still fires reliably until I get to the range tomorrow.
  18. CaddmannQ

    CaddmannQ 12g Supporter

    Messages:
    7,430
    I ran about 30 rounds in the 464 today, and it has never run better. No missfires, no jambs, no problems.

    I shot both Hornaday American Whitetails 150grn and Winchester 170grn, and was very pleased.

    The mainspring mod worked great, and she fired every time, making a fine dent in the primer. I may be able to reduce the pressure even more.

    Frankly I'd advise all 464 owners to do this mod. It's easy, and easy to undo.

    The modded Thompson-style scope base worked great, and that old Tasco scope works great too.
    20160206_230427-1.jpg
    Last edited: Feb 8, 2016
  19. CaddmannQ

    CaddmannQ 12g Supporter

    Messages:
    7,430
    Folks, I tend to take a lot for granted when I post this stuff. Things like, if you're taking a gun apart to do more than clean it, you probably understand the lockworks, you know something about metal working, metalurgy, and small mechanisms.

    So if you blow it, know that I warned you to be careful. ;)

    This is how I reduced the spring pressure.

    In the pic, my sloppy yellow arrow points to the angle of the stamped link, which I bent tighter to effectively shorten the link.
    2016-02-07 18.03.17.jpg

    This shows the link before the second bending. I did it in 2 steps because I was afraid to overshoot.

    This is an ingeniously designed but cheaply made steel stamping, and because of the design, slight variations could cause different 464's to have somewhat different spring pressures.

    Mine was clearly way more than required for a good primer strike.

    There were other ways to accomplish this, but I took the easiest way. I may still dress the link down a little, but if the pressure gets too low, the link might become dislodged in operation.
    Last edited: Feb 7, 2016
  20. Nkoch1985

    Nkoch1985 Copper BB

    Messages:
    2
    I have a 464 30-30...every so often a round gets stuck on its way into the chamber...anyone else have this issue

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