HELP! LP Fusion won't extract case?

Mudflap621

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Ok guys don't blast me but this is my first custom build as well as first 700 based. Finally received my barrel so just got done torquing it down.

LP Fuzion action
6mm BRA Prefit shouldered barrel
Brand new Lapua brass

I made two dummy rounds last night while barrel was off getting CBTO measurements and using these once I chamber the round it won't extract the case when running the bolt. What am I missing? I measured the bolt head and it looks to be .480 and when I much a round down on the bolt seems that the extractor just barely catches. Ill attach a pic of bolt head.
tempImagetk5Drk.png
 

waveslayer

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    No expert here, but the spring for the extractor is it installed correctly? Also the plunger spring ?
     

    Mudflap621

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    No expert here, but the spring for the extractor is it installed correctly? Also the plunger spring ?
    Hopefully this is brand new action never disassembled. I was hoping not to have to fly springs all over the place this early in the game but if nothing looks out of the ordinary it might be inevitable.
     

    Tokay444

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    Does a case snap into the bolt face and stay there with the bolt out of the action?
     

    Tokay444

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    What did you measure the ID of the bolt face with?
     

    Tokay444

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    Ok. Then I think I’m going to align with the .308 bolt face and magnum extractor theory as well.
     

    Mudflap621

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    Thanks guys i sent an email into LP hopefully that’s it seems like easy fix.
     

    Mudflap621

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    Brian at Lone Peak is good people. Give a call or send them a note through their website.
    Already sent them a note I’ll give it a few days to respond. Not worried at all I’m sure they’ll take care of it just wanted to make sure I wasn’t missing something on my end.
     
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    Mudflap621

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    New extractor showed up today but now how do I change it. Tried finding a video but haven’t had any luck. I see the roll pin, just punch it out or is there some secret steps. I don’t wanna fuck it up.
     

    Mudflap621

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    I fingered it out. Seems to be working well tomorrow will be the maiden voyage.
     
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    Mudflap621

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    Well got the extractor issue resolved but might have to look at the FF load a little more. Ran first 10 rounds down the tube today and first two quite heavy bolt lift as well as all showed ejector marks/swipe. Chrono showed an average of 2756 with SD of 10 and ES of 29.

    Lapua Virgin 6br brass
    Hornady 105 HPBT
    29Gr IMR 4064
    BR4 Primers
    .020" off lands

    tempImageanVBVw.png
     

    Mike Casselton

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    For fire forming, you should as a minimum have the bullet in contact with the lands.
    Does your brass have a slight crush fit without a projectile?

    Either issue can cause the base of the brass to slam against the bolt face causing flattening and a swipe mark.
     

    Mudflap621

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    Seems to have slight crush as I get a very faint swipe on virgin brass. Because of this I kinda figured didn’t need to jam bullets.

    Maybe it’s worth trying to pull bullets out a bit to get jam and try again? Velocity seems to be acceptable for a FF load correct? This is brand new 26” PVA barrel.
     

    kthomas

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    That doesn't seem right.

    I have no experience with that specific powder, my fireform load is 29.5 grains H4895, which produces a velocity of ~2920 fps in my 28" Krieger, and ~2850 fps in my wife's 24" Brux.

    No issues with pressure such as ejector marks. Bullets are seated 20 thou off of the lands, no jamming.
     
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    Mudflap621

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    Its been suggested to me possible bur on ejector or something, this is a brand new action. I am going to take ejector out and maybe try to knock down anything around ejector hole as well as ejector face itself. KThomas my ejector definitely looks a lot flatter with less radius than yours pictured.

    Since the heavy lift pretty much went away after first two rounds possibly contamination within the chamber? Im having a hard time believing there is pressure at these speeds myself but just being cautious as I don't wanna fuck anything up.

    For testing im also thinking of seating 10 rounds .010" into the lands and see if these act any differently.
     

    Mbaysinger89

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    Did you clean the barrel and chamber first? Oil in the chamber can make that happen.
     

    Mudflap621

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    Water can too, was it raining?
    Was a slight drizzle, bore and chamber were cleaned. I think I might have narrowed it down. After pulling the ejector I did notice a bur around the ejector opening so I tried massaging it out the best I could. While that was out I also pulled the FP and chambered a piece of virgin brass and the bolt just fell closed. Although I thought there was a slight crush it seems like there is not.

    For those that seat into the lands while fire forming what would you suggest?
     

    Mbaysinger89

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    Find your lands with the hornady tool or split case method, seat into the lands a few thou, shoot.

    If you dont want to do that, neck the brass up to 6.5mm. Size it back down to 6mm in very small increments,creating a false shoulder, until you can close the bolt on empty brass with a little crush.
     

    spife7980

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    For those that seat into the lands while fire forming what would you suggest?
    Seat the bullet as long as you can and still be able to close the bolt without hurting your hand. Just test and see, the more you jam and keep the case head pinned back against the bolt face the better the end results will be.

    That said, an ackley chamber should index on the neck shoulder junction. Sounds like your brass is short or your chambers long. So since it’s not touching you can false shoulder- you neck them up with a 6.5 mandrel and then size the neck back down until you can again feel that larger brass donut on the brass crush into solid contact when chambering without so much pressure it hurts your hand.

    But a healthy jam of the bullet into the lands will ensure a good contact for consistent ignition as well.
     

    Mike Casselton

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    ^^^^
    What spife said.

    If you decide to add in bullet jam to case jam they'll come out really nice too.

    Hint:
    it's worth the effort to do both.
     
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    kthomas

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    Seat the bullet as long as you can and still be able to close the bolt without hurting your hand. Just test and see, the more you jam and keep the case head pinned back against the bolt face the better the end results will be.

    That said, an ackley chamber should index on the neck shoulder junction. Sounds like your brass is short or your chambers long. So since it’s not touching you can false shoulder- you neck them up with a 6.5 mandrel and then size the neck back down until you can again feel that larger brass donut on the brass crush into solid contact when chambering without so much pressure it hurts your hand.

    But a healthy jam of the bullet into the lands will ensure a good contact for consistent ignition as well.

    There *should* be 4 thou of crush on the parent (6BR) cartridge case, when fireforming. Hence the lack of need in 6BRA to jam bullets our create false shoulders when fireforming.

    I would have to agree with the guess that the chamber is probably slightly long, requiring extra steps to properly fireform. Which is a shame, as the 6BRA is really simple to fireform, when everything is made to spec.

    Maybe reach out to PVA and try to figure out what the actual problem is? At this point it may be better to address the root cause, then to use bandaid solutions.
     

    Mudflap621

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    There *should* be 4 thou of crush on the parent (6BR) cartridge case, when fireforming. Hence the lack of need in 6BRA to jam bullets our create false shoulders when fireforming.

    I would have to agree with the guess that the chamber is probably slightly long, requiring extra steps to properly fireform. Which is a shame, as the 6BRA is really simple to fireform, when everything is made to spec.

    Maybe reach out to PVA and try to figure out what the actual problem is? At this point it may be better to address the root cause, then to use bandaid solutions.
    Yes the simplicity of fireforming was my main reason for going BRA over dasher lol. I’ll reach out to them see what they think. I tried probably half a dozen peices of virgin brass and stripped bolt fell on all of them so either the Lapua brass is short or chamber a tad long.

    I have a comparator for 40 degree shoulder when using that the fireformed brass is .001 longer. I dunno if I can use that as a solid number seeing the br brass has a different shoulder angle.
     

    spife7980

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    Got a go gauge?

    With the ejector stripped from the bolt so it’s not pushing on things-
    you can add a layer of scotch tape at a time to the brass case head, trim the overlap with a razor around the edge, and measure how much further it takes for to feel the br brass to touch when you chamber it.
     
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    Mudflap621

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    Got a go gauge?

    With the ejector stripped from the bolt so it’s not pushing on things-
    you can add a layer of scotch tape at a time to the brass case head, trim the overlap with a razor around the edge, and measure how much further it takes for to feel the br brass to touch when you chamber it.
    I don’t have a go gauge but will use scotch tape method later today to see how much longer it is.
     
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    Mudflap621

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    Ok couldn't wait. I have slight resistance on one layer of tape will not close on its own with two layers of tape.
     

    spife7980

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    Shoot, that’ll form fine. I would still have the bullets by feel j til you can tell it’s solid but you can still work it.

    Did you start low and work up to that 29 grains of 4064? How many rounds do you have loaded up already? A little imprint doesn’t bother me but the swipe means it’s really hammered in there.
     

    Mudflap621

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    I have 40 rounds already loaded up at 29. I was suggested this as a low end starting point and with 20 thousandths jump I was seeing 2750fps. I think that swipe was definitely due to the bur around the ejector opening.
     
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