Over trimmed brass

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  • Moorvogi

    Firearm Advocate
    Dec 28, 2014
    855
    I have the worlds finest trimmer in a couple different calibers. I have one in 308 that I use on 30-06 brass for dummy rounds.

    I’m not loading super hot loads. What are your thoughts on firing loads that has the deck trimmed too far? I know too long is an issue because of pressure. But what about too short? It’s a colt action rifle and zero issues feeding the dummy round a couple hundred times.

    I’m thinking, if the COAL length is the same…. I’m fine.
     
    I have the worlds finest trimmer in a couple different calibers. I have one in 308 that I use on 30-06 brass for dummy rounds.

    I’m not loading super hot loads. What are your thoughts on firing loads that has the deck trimmed too far? I know too long is an issue because of pressure. But what about too short? It’s a colt action rifle and zero issues feeding the dummy round a couple hundred times.

    I’m thinking, if the COAL length is the same…. I’m fine.

    If there is still enough neck length to provide proper tension, I would use them.
    I'm still sitting on .22-250 and .300Win Mag brass for you.
     

    Moorvogi

    Firearm Advocate
    Dec 28, 2014
    855
    If there is still enough neck length to provide proper tension, I would use them.
    I'm still sitting on .22-250 and .300Win Mag brass for you.

    Mmmmm. Awesome! Crips are planted and too tall at this point. Will you be ready in mid November for some 500 yards dueling tree work!?

    Ps: I’ve started pew ring shooting golf balls… at 500 yards. That’s a fun hard shot.
     

    Moorvogi

    Firearm Advocate
    Dec 28, 2014
    855
    If there is still enough neck length to provide proper tension, I would use them.
    I'm still sitting on .22-250 and .300Win Mag brass for you.

    Mmmmm. Awesome! Crops are planted and too tall at this point. Will you be ready in mid November for some 500 yards dueling tree work!?

    Ps: I’ve started shooting golf balls… at 500 yards. That’s a fun hard shot.
     
    Mmmmm. Awesome! Crips are planted and too tall at this point. Will you be ready in mid November for some 500 yards dueling tree work!?

    Ps: I’ve started pew ring shooting golf balls… at 500 yards. That’s a fun hard shot.

    Mmmmm. Awesome! Crops are planted and too tall at this point. Will you be ready in mid November for some 500 yards dueling tree work!?

    Ps: I’ve started shooting golf balls… at 500 yards. That’s a fun hard shot.

    You can say that again.
     

    Moorvogi

    Firearm Advocate
    Dec 28, 2014
    855
    This.

    Your recommended trim to length is 2.484.

    You can be as short as 2.474, and still remain within SAAMI specs.

    K. So what happens if it’s too short. Say 2.473. Exaggerating a bit but does the world try to divide by zero and self implode?

    I won’t hold anyone but my self responsible but… I got to wonder. Billet searing depth will be off but COAL is the same. It’s bolt fed not semi auto.
     

    8milimeter

    RICHARD (dino)
    Feb 15, 2009
    486
    Frederick, Md
    2.473 is fine. unless you are using 110g or 147 boat tail bullets. Even those are Ok if you have enough neck tension.
    My lee case length tool tip is short due to thousands of uses. All my 30-06 brass is 2.470.
    I have shot thousands of rounds like this using 155 BTHP in bolt guns and Garand's.
     

    Uncle Duke

    Ultimate Member
    MDS Supporter
    Feb 2, 2013
    11,662
    Not Far Enough from the City
    K. So what happens if it’s too short. Say 2.473. Exaggerating a bit but does the world try to divide by zero and self implode?

    I won’t hold anyone but my self responsible but… I got to wonder. Billet searing depth will be off but COAL is the same. It’s bolt fed not semi auto.

    You didn't "say" what your case length was to begin with. You're still not saying.

    I'm not going to try to deal in the hypothetical. Dimensions are dimensions are dimensions. Let's say that at some as yet undetermined point, too short is indeed too short.

    You have the specs. Whether you choose to pay attention to them... or not? That is entirely your choice and responsibility. Just like you stated.
     

    Biggfoot44

    Ultimate Member
    Aug 2, 2009
    32,876
    " Spec " includes minus .010 .

    Actual issues would involve sufficient Neck Tension with a specific bullet at specific OAL .
     

    Moorvogi

    Firearm Advocate
    Dec 28, 2014
    855
    2.473 is fine. unless you are using 110g or 147 boat tail bullets. Even those are Ok if you have enough neck tension.
    My lee case length tool tip is short due to thousands of uses. All my 30-06 brass is 2.470.
    I have shot thousands of rounds like this using 155 BTHP in bolt guns and Garand's.

    667A63AE-6254-407E-9D5A-8F709716DFAF.jpeg


    The one on top is normal trim. The bottom one is “excessive”.
     
    Last edited:

    Moorvogi

    Firearm Advocate
    Dec 28, 2014
    855
    " Spec " includes minus .010 .
    Actual issues would involve sufficient Neck Tension with a specific bullet at specific OAL .

    Fair enough. That seems to be the common answer but the additive portion of this question is, what happens if there isn't sufficient neck tension? Accuracy is sacrificed, does it become a pipe bomb?! I'm assuming it becomes an accuracy thing. If so, it doesn't matter for plinking or deer under 30 yards (tree-stand deer management).
     

    GunBum

    Active Member
    Feb 21, 2018
    751
    SW Missouri
    Neck tension matters for accuracy, bullets moving in/out of the case under recoil, and moving when chambering. There are probably some other problems, but those are the more likely issues. FWIW, there are plenty of cases that have very short necks and don’t pose a problem with the right bullet selection.
     

    Moorvogi

    Firearm Advocate
    Dec 28, 2014
    855
    Neck tension matters for accuracy, bullets moving in/out of the case under recoil, and moving when chambering. There are probably some other problems, but those are the more likely issues. FWIW, there are plenty of cases that have very short necks and don’t pose a problem with the right bullet selection.

    Ya, i can see the movement from recoil and chambering which is why i specified it was a bolt action. There isn't much recoil either so i think it'll be fine. I could be super paranoid and use a felt marker to mark the bullets at the tip. if i go to chamber one and there is no mark, it got seated too deep from recoil.

    i'll get a decent trimmer eventually but i dont want to spend more $ on reloading while there is still an issue obtaining reloading components. i'll "make due" with what i have.
     

    Biggfoot44

    Ultimate Member
    Aug 2, 2009
    32,876
    If bullet is forced Into the case , nasty , even destructive pressures can happen .

    Bullets traveling out of the case can cause jams . plus accuracy issues .

    Bullets more or less staying in position , but insufficient tension can result in inconsistent powder ignition , poor accuracy , etc .
     

    PowPow

    Where's the beef?
    Nov 22, 2012
    4,712
    Howard County
    i'll get a decent trimmer eventually but i dont want to spend more $ on reloading while there is still an issue obtaining reloading components. i'll "make due" with what i have.

    I don't have one of those, but I'm curious as to how it can overtrim - especially by that much. It indexes off the shoulder, right? I've actually thought about getting one versus my drill-powered LE Wilson.
     

    Moorvogi

    Firearm Advocate
    Dec 28, 2014
    855
    I don't have one of those, but I'm curious as to how it can overtrim - especially by that much. It indexes off the shoulder, right? I've actually thought about getting one versus my drill-powered LE Wilson.

    It's super easy to set up.. the only reason it's overtrimming is becuase im using a .308 win trimmer to trim 30-06. It works like a charm for the designated calibers. I could change the depth of the endmill bit to NOT over trim... especially while i'm not reloading 308 at the moment.... that might be the easiest solution without spending extra money.
     

    PowPow

    Where's the beef?
    Nov 22, 2012
    4,712
    Howard County
    It's super easy to set up.. the only reason it's overtrimming is becuase im using a .308 win trimmer to trim 30-06. It works like a charm for the designated calibers. I could change the depth of the endmill bit to NOT over trim... especially while i'm not reloading 308 at the moment.... that might be the easiest solution without spending extra money.

    Oh, I missed that critical detail in your first post. Makes total sense now.
     

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