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Mossberg MVP LC chamber problems?

Discussion in 'Firearm Maintenance, Safety And Troubleshooting' started by Daryll, May 29, 2019.

  1. Daryll

    Daryll .270 WIN Supporter

    Messages:
    336
    I've had my MVP LC in .308 for a couple of years now and is been fine up until recently, when i noticed some of the fired cases had a bright ring around them.

    At first I though this was a sign of imminent case head seperation, but then realised that it wasn't in the normal place... these rings were over half way up the case.

    Tonight i investigated properly and used my cheapo USB webcam / bore scope to see what was happening... i could see this:
    [​IMG]

    The ring closest to the camera is where the ring is on the cases... and if i lay a case on the outside of the chamber, with the rim approx level with the start of the chamber, the ring on the case is level with the edge of the recoil lug...

    The ring on the cases is actually a very slight raised rib, you can only just feel it with your fingernail, so that ring in the chamber is actually a small depression.

    So whats happening?? i've had the action out of the stock and everything feels tight.. i did wonder of the barrrel was coming loose, but no..

    Any ideas..?

    And any thoughts on whether its still safe to shoot?? I'm supposed to be using this weekend..
  2. hombre243

    hombre243 .30-06 Elite Member

    Messages:
    1,135
    Call Mossberg or a licensed gunsmith before you fire it again.
  3. Daryll

    Daryll .270 WIN Supporter

    Messages:
    336
    Good news... took the rifle to my gunsmith this evening and hes given it the all-clear. Using his hi-res borescope you can see that the ring is actually a machined groove running around the chamber, so has been there since manufacture.

    If anyone else has an MVP LC, can they have a look and see if theirs has the same..?

    I'll drop Mossberg Customer Services an email asking if thats normal, and if so what is its purpose??

    The gunsmiths theory is that maybe its a relief groove to allow the brass somewhere to flow... something to do with it being a 7.62x51 and .308..??
    hombre243 likes this.
  4. Daryll

    Daryll .270 WIN Supporter

    Messages:
    336
    Sorry, duplicate post..
  5. hombre243

    hombre243 .30-06 Elite Member

    Messages:
    1,135

    You have brought up a memory and may have answered a question. I had a Savage 308 Bolt gun and there was an extra groove that started at the rifling, cutting through the lands at a slower twist than the rifling twist. It made one turn and ended at a groove. My friend was Marine Armorer and he had never seen anything like that. Tonight he mentioned that recently someone mentioned to him that that method of pressure bleed, or redirection started with an AR-10, and the purpose was to redirect some gas back towards the casing to help with case extraction. No proof, just hearsay on the latter. My what-if, on the Savage groove. I think it is a pressure relief to bleed excess pressure in a 308 chamber when using 7.62x51 spec loads. One never knows what some companies do to make a private model their own. I got the Savage from Dick's. I wish I would have kept it. It was a dime sized group shooter at 100 yards. I didn't have any longer ranges so I don't know exactly how good it was, but I came back from TX and didn't need a 308 so I sold it. I am also sorry now that I didn't keep the bore scope pictures.
  6. Daryll

    Daryll .270 WIN Supporter

    Messages:
    336
    OK, so i'm not impressed with Mossberg's Customer service... heres the email conversation..

    Me:
    Hi, I have a question regarding my MVP LC in .308.
    I recently had some bright rings appear on fired brass from this rifle, and while investigating I discovered a depressed ring around the chamber. Fearing that it was a fracture line, I took it to my gunsmith and he looked with a hi-res borescope.
    I seems that the ring is a machined groove around the chamber, presumably during manurfacture. Is this normal?? and if so, what is its purpose?
    Regards
    Daryll.

    OFM:
    Hi Daryll,
    This reads like the bullet seat or chamber shoulder and this is normal. Please let us know if we can be of any further assistance.

    Me:
    Hi, I'm afraid i don't think this is either of those.... the ring on the case is about half way down the case down from the case shoulder.

    [​IMG]

    If i lay the case on the outside of the chamber the bright ring is roughly where the recoil lug is fitted between the barrel and action.

    Using my cheap USB bore-scope (apologies for the quality!) you can see the ring nearest the camera
    [​IMG]

    and this is the ring using the 90 degree angle.
    [​IMG]

    Regards

    Daryll.

    OFM:
    Hi Daryll,
    The pictures are excellent! Thank you. This does represent a different situation. The chamber should be smooth. Please send us the serial number of the gun for review.

    ME:
    Serial number is MVP060xxx

    OFM:
    Hi Daryll,
    Please go to mossberg.com and click on support and then service ticket request. Kindly complete the service ticket and then send the gun to the address provided.
    Box the gun securely and send it to Mossberg Service Center, 1001 Industrial Blvd, Eagle Pass, TX 78852.
    Our team will inspect the rifle and repair as needed. Please include a note outlining the issues with the rifle.

    Me:
    Hi, thanks for that, although that may be difficult as i'm in the UK. Will it be a different process to ship it to the Uk distributor?

    OFM:
    Hi Daryll,
    Then you will need to find a local gunsmith and have them roll the chamber or polish the inside of the chamber.
    Thank you and best regards,

    So..... as I'm outside the USA they can't help, (although they're happy to sell them here), and i've got to get a manufacturing fault fixed at my own cost...??
    And wouldn't polishing out the groove or "rolling the chamber" (whatever that is), make the chamber way oversize??

    I was thinking about p/x'ing this MVP LC for a MVP Varmint like my .223, but now I'm wary of getting another Mossberg...
  7. Woods Wanderer

    Woods Wanderer .410

    Messages:
    50
    I wonder if there is a Mossberg repair facility on the Continent that you could send it to?
  8. Daryll

    Daryll .270 WIN Supporter

    Messages:
    336
    We have a Mossberg UK Distributor (York Guns), but I'm not sure if they're a service centre... Mossberg Customer Services didn't appear to think so...

    Discussing it with my Firearms Dealer (who i bought the rifle from, brand new), he said that if Mossberg will acknowledge that its a manufacturing fault, he can go to York Guns and try to get a replacement... so I emailed OFM last night asking the question.

    To be honest, I can't see OFM admitting that its their fault without inspecting the gun.... but we'll see what reply i get.

    Daryll.
  9. Daryll

    Daryll .270 WIN Supporter

    Messages:
    336
    Still not helpful... todays responses..

    Me:
    Ok, can you confirm that this is a manufacturing fault please, that way we can go to the Uk distributor and get a replacement.

    OFM:
    This ring needs to be repaired or the barrel needs to be replaced. We would suggest working with a local gunsmith that has access to parts in the UK.

    Me:
    Mossberg obviously have export licences for you to send guns to the Uk Distributor (York Guns), so cannot you send a replacement barrel to York Guns, or authorise them to give me a replacement rifle?

    OFM:
    The distributor will need to order the correct part and then it would be shipped using a valid export license. There is a documented process in place that is regulated by the US Government.
    There are no other options.


    So they won't admit its a manufacturing fault, and won't send a replacement barrel to the UK distributor unless they ask for one..

    My RFD has emailed the Uk Distributor to see what they can do, but as its out of warranty, they probably won't do anything for free

    So... I have a possibly dangerous rifle due to a manufacturing error, but the manufacturer won't help... I can either continue to shoot it, scrap it and buy another (non-Mossberg!) rifle, or sell it... but my morals won't allow me to sell a defective rifle...

    Another option would be to get it re-barreled, but that would probably cost more than a new rifle..

    I'm between a rock and a hard place...
  10. Daryll

    Daryll .270 WIN Supporter

    Messages:
    336
    Update to this... my RFD followed it up through the Uk distributor, who passed it up to the Worldwide distributor, who went back to OFM.

    OFM have come back and said:

    "I reviewed the conversation from the owner of the rifle and our customer service department. I also inspected the images provided. Our customer service representative made an error in their assessment of this case. These marks are imprints from the chamber reamer during production. Reamers can often leave internal marks during this process and these are not of any safety or performance concern. I also reviewed my findings with our bolt action rifle engineer and he agreed with my findings. I apologize for the mis-information provided by our customer service representative, he has only been with the company a few months and he should have requested another employees review before making any statements."

    So they reckon its a tooling mark and normal..!?

    I've lost confidence in the rifle so next Friday I'll be taking down to a gunsmith who specialises in re-barrelling, and get a 24 or 26'' match barrel put on it...
  11. Bobster

    Bobster .30-06 Supporter

    Messages:
    2,193
    Maybe a mild polish of the chamber?
  12. Daryll

    Daryll .270 WIN Supporter

    Messages:
    336
    A polish would't work... the groove is at least 0.5mm deep so polishing that out would make the chamber out of SAMMI spec...

    Once I've had it rebarrelled, I'll get the gunsmith to section the chamber on the old barrel so we can see the true extent of it.

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