Why such a poorly designed bolt on the Mossberh MVP 556

Discussion in '223 / 5.56 MVP and Variants' started by Greywolf224, May 13, 2016.

  1. Greywolf224 Greywolf224

    Member Since:
    May 10, 2016
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    Folks this may have been covered before as I am sure that it has, but did not come across anything.

    The bolt assy seems to me poorly designed at best. For example the broken extractors, flimsy flapper spring and very lose fitting bolt into the receiver. For the price of the firearm and the longevity of the Mossberg company, I would have expected much better quality. Especially in the extractor design. I have seen much better design's in much cheaper fire arms.

    Therefore does anyone know of or does a replacement high quality bolt exist?
  2. spamassassin Well-Known Member

    Member Since:
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    To your main question, no, one does not exist to my knowledge.

    The factory bolts themselves are just fine and your criticism of them is also not uncommon but it is perhaps more expectation overreach than product shortfall. I've seen exactly zero confirmed reports of the admittedly flimsy seeming flapper spring being an issue. Not even mine and I abuse my MVP more than almost anyone will ever do. Bolts not fitting snugly is a matter of reliability, not quality. Got an old Mauser, pull the bolt back and give it a wiggle. Some of the finest bolt rifles ever made and every one rattles, right until you lock it up. Just like the MVP.

    The extractor itself isn't a bad design. It's common actually and despite the material selection on Mossberg's part being severely limp wristed it's a very workable design. Savage uses the hell out of the same basic design in their bolt guns. Winchester used the same basic design on their Model 70 push feed guns. Ruger uses them on the American series. I would imagine it might be possible to do a Sako extractor conversion on it but that would likely weaken the bolt head too much and the extractor, spring and retaining pin would all have to be custom engineered, so totally not cost effective.

    Crosshair Precision makes a good replacement extractor and you can now get them right from Mossberg as well. CHP's is better in my experience. I've busted no less than 4 extractors and 3 of those were CHP made. CHP made or no, you abuse things and parts break.

    The MVP is in my opinion a sub-standard rifle in many ways, especially for the amount it cost at retail. It's also a big sack of gimmicks and the QC has been lackluster to say the least. That said, we all had the chance to carefully examine the rifle before purchase and we all decided to get suckered in by the AR mag compatibility and so we all get to sleep in our self-made beds. Is Mberg losing some reputation points because of this? Yeah but really, how much did they have to begin with?

    Now, I need to order another pair of extractors before my next match.
    Fritz373, Andy and addicted like this.
  3. Greywolf224 Greywolf224

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    May 10, 2016
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    Thanks much for the unbiased response. Yes my savage 110 as do some other rifles uses the same extractor design but as you said the choice of materials used is very substandard. Seems like my savage uses a heaver and larger extractor and possibly hardened not sure.

    I am sure that through design testing Mossberg had to of break a few extractors themselves. But than again something we will never know.
  4. spamassassin Well-Known Member

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    The real engineering problem with the MVP's extractor IMO was trying to pull that off on such a small scale while using brittle metal for them and using a detent ball instead of the cone-with-probe type detent that winchester used in the model 70 push feed. The winchester extractor doesn't lose so much mass/strength to the cutout for the detent ball. All winchester needed to do was make a very small spot to fit the tip of a cone and then through-drill a hole that the probe tip of the detent sticks into. The side effect of the Winny method is that removing the extractor is greatly simplified since you can stick a paper clip through the hole to push the detent down. Much easier to do without launching the detent and spring across the room/range.

    Of the extractors that I've busted, the factory one blew the center out leaving the ears still in the bolt head (not my fault, crap part). 1 other broke almost in half (my fault). Another had the ears ripped off of it (my fault). Another was broken but still semi-functional (my fault). The same things that shatter MVP extractors, don't even phase my savages. You have no idea how many times I've had to beat the bolt of my savage rifles open with a mallet and never broke one of their extractors. (Note to self, buy some spare savage extractors now that you've jinxed yourself.)
  5. Greywolf224 Greywolf224

    Member Since:
    May 10, 2016
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    Lol....to let my son continue shoot some, I used a wooden dowel long enough to push the spent shells out. I found that just letting the dowel drop down the barrel under its own weight was enough to dislodge the spent shell. Got monotonous to do each time.
  6. spamassassin Well-Known Member

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    I got to do that once in the middle of a match. Super fun. I still carry a full size Dewey rod with my rifle to every match I go to. Never know when you'll need it.
    Greywolf224 likes this.
  7. wood chucker Moderator

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    Pretty much what Spamassasin said, To date there has been zero/zip/zilch/nota not one reported problem with the feed flap gizmo.

    The bolt "slop" is operation clearance like Winchester Model 70, '03 Springfield, SMLE, Mauser '98, M-1917, Jap Type 99 etc all have for reliability in adverse conditions. Unless a person is familiar with the great bolt action battle rifles the clearance will take some getting used.


    The overall design is nothing new mostly a clever re hash of what came before. The barrel and lock nut set up and the floating bolt head are a copy of Nicholas Brewers design he did for Savages 340 and 110. The receiver looks like cross between Remington model 700 and Howa 150o. The trigger technology is based on the same 110 year old patent that all modern adjustable triggers are.

    The feed flap on the small action 5.56 and the feed bumps on the short action 7.62 are new and effective solutions that finally solve and old problem.
  8. bombadillo Moderator

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    The only issue I ever had was when I went from a factory stock to an MDT LSS Chassis. It seemed to not want to pick up the next round sometimes, but then I figured out if I used Pmags (which I am NOT a fan of) it totally alleviated the problem.
  9. Andy New Member

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    So how do I get ahold of CHP??? It sounds like he went out of business...
  10. wood chucker Moderator

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    Out of business ? not by a long shot. Making changes ? yup.
  11. Andy New Member

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    Feb 6, 2017
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    When I see a posted way to order these parts I will order some extractors, springs, and the detent ball...Kinda wish Tromix would make these items...they have great customer service and better communications :cool:
  12. Andy New Member

    Member Since:
    Feb 6, 2017
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    Just ordered Mossberg replacement extractor, detent ball, and extractor spring from Mossberg today...$17.99 (includes shipping)...
    Just to have in case of failure...ships in 5 days.
    Lady on the phone was great !!! Very helpful !!!
  13. Andy New Member

    Member Since:
    Feb 6, 2017
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    Parts came in from Mossberg today! Now that is what I call service:)
    TexasPete likes this.

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