Does seating depth or powder charge come first and WHY

Discussion in 'Reloading Forum (All Calibers)' started by AJC, Jan 10, 2019.

  1. AJC

    AJC

    Joined:
    Sep 30, 2018
    Messages:
    253
    So my plan was to take a "middle of the road" powder charge and do a seating depth test, and then refine where i went from their with a ladder test. Is each process time critical or should one be done first. I know that after the first go around i had planned to go back for fine tuning, but is there a series of events that makes things go faster or gives better results?

    My plan example: 223 rem 30" shilen barrel and savage action. Lapua brass
    1. choose 24 grains varget. I have been shooting 24.4
    2. Do a berger VLD seating depth test.
    3. Do a ladder test in .2 or .3 grains from 23-25 grains and stop when i see pressure signs.
    4. Check a similar powder like h4895 to see if it performs better in the same ladder test.
    5. Check a different bullet of the same weight like eldx, and a match king.
    6. depending on results try a different shape like a 77 gr MK
    If i dont have a decent shooter at this point i would be off grid and begging for help.
     
    Last edited: Jan 10, 2019
  2. mikecr

    mikecr

    Joined:
    Nov 26, 2004
    Messages:
    3,316
    Sounds good, provided you had fire formed cases used for ladder testing.
    Swapping bullets takes you back to seating testing, but that's ok, just back off the charge again.
     
  3. MikeMcCasland

    MikeMcCasland Silver $$ Contributor

    Joined:
    Apr 24, 2011
    Messages:
    259
  4. AJC

    AJC

    Joined:
    Sep 30, 2018
    Messages:
    253
    How much change in seating depth will take you out of a powder node.
    Aren't most powder nodes on the high end of speed and pressure, and not yet having quick load "i will be getting it at some point" Do you run pressure risks by 1.going forward into the lands, and moving back by reducing case capacity? Not that i have any way of knowing or checking that, but by not being able to check, would it not be safer to be lower in the pressure range when making these changes? (seating depth)
    P.S. i am searching for understanding and trying not to blow my face off.
     
  5. MikeMcCasland

    MikeMcCasland Silver $$ Contributor

    Joined:
    Apr 24, 2011
    Messages:
    259

    How much adjustment will bring a load out of the node is dependent on a lot of factors. I pretty much use Erik's method, except once I find a powder node, I'll jam them .015 and work back to .020 off the lands. If I can't find anything there, I'll load up a few with that charge weight and give Bergers method a try (.030 off, .060 off, .090, .120 off etc.).


    As far as "blowing your face off" it's very unlikely that's going to happen unless you're seeing pressure signs, then seat the bullet way in there. You don't mention what bullet weight you're running, but for reference, I run 90gr Berger VLDs in Lapua brass at a slightly higher charge weight than you're using, and I went from .015 jammed to .020 off and never saw pressure signs (mind you the rifle is throated to run 90s seated way out there).

    Secondly, with Varget and H4895 I don't think you can get enough powder in the case to blow it up.

    Not sure what you're going to use this for, but if it's for any kind of competition, skip the 77gr bullets; those are developed for ARs. For shooting heavies out of bolt guns, you should be running 80gr-90gr bullets. It would also help to know the specs of your reamer and your twist.

    Lastly, take my words with a grain of salt. I've only started messing with .223s running 90s as of late. It's been fun (and tuned relatively easy), but there are a lot of guys on this forum who have burned out many .223 barrels in F-T/R over the years.
     
  6. AJC

    AJC

    Joined:
    Sep 30, 2018
    Messages:
    253
    I was running 80 eldx's with my dad and the gun was just built. I shot one Silhouette match that goes to 600 and if i can find that type of match in Georgia when i move i would like to continue. Its a 1:7 twist so fast but we discussed not trying the 6.5 or running the 90 due to the harder tuning. The 77 is the largest i can find that is not the VLD style to the go on that was hopefully if i was falling badly that it may be easier to get a tune there and get me on the right track. It honestly shot good for my one and only time out a 39 of 50. Thats not perfect but there were a lot of firsts in that 1. the gun was brand new, 2.The cases were brand new and not formed, We picked the 24.4 load off the 6mmbr because we ran the same bullet weight, and i had no sight settings when i showed up. Beat half the field working threw the wind where people i was shooting against were using 6mmbr and 6mmbrx so i had several major competitors.
     
  7. MikeMcCasland

    MikeMcCasland Silver $$ Contributor

    Joined:
    Apr 24, 2011
    Messages:
    259
    If you're beating 6BRs and BRXs at 600 with a .223 and 80gr bullets while fire forming, don't mess with anything. It's already shooting pretty well. :)
     
    SPJ and dmoran like this.
  8. AJC

    AJC

    Joined:
    Sep 30, 2018
    Messages:
    253
    They were on the line, i wish i was beating them but it was an example of some of the guns on the field. To even be in the running i was happy and the only one running a 223. This match was at Pala in San Diego and the field was a huge spread. I made AA won AA class and my dads shooting partner which is a regular so i was stoked. He was shooting 6mmbr
     
    dmoran likes this.
  9. dmoran

    dmoran Gold $$ Contributor

    Joined:
    Nov 25, 2004
    Messages:
    2,955
    @AJC
    100% agree with @MikeMcCasland ... by your actual match results sounds like you do not need full blown load workups. And strongly suggest to only proceed with small single step changes of the same components that you already are using. Likely the testing of other components and big changes from what you all ready have going, very well may end up a waste of barrel life and component expense.
    Just my 2-cents
     
    dogdude and MikeMcCasland like this.
  10. AJC

    AJC

    Joined:
    Sep 30, 2018
    Messages:
    253
    Well as i respect everything we have discussed so far, Your advice in other threads has been solid and appreciated. i may make my initial trial on another gun. I only have 3 to figure out a system on, and i built the 223 to really learn on. It was never designed to be an expensive proposition and i just rebarreled a factory savage 308 my dad hated. I have never even shot it on paper to see if its good or i was just lucky ;)
     
  11. lawman29

    lawman29

    Joined:
    Jun 20, 2013
    Messages:
    262
    What are you using for a powder scale?
     
  12. AJC

    AJC

    Joined:
    Sep 30, 2018
    Messages:
    253
    Here she is
     

    Attached Files:

    dmoran likes this.
  13. AJC

    AJC

    Joined:
    Sep 30, 2018
    Messages:
    253
    Charge master 1500
     
  14. AJC

    AJC

    Joined:
    Sep 30, 2018
    Messages:
    253
    I got rid of those stupid scope mounts and got a proper set of nightforce rings and base. Haven got to shoot her after.
     

    Attached Files:

  15. MikeMcCasland

    MikeMcCasland Silver $$ Contributor

    Joined:
    Apr 24, 2011
    Messages:
    259
    In that case, put it on paper, and get some velocity readings.

    If you're slow, bump the powder charge a bit.
    If you're at a good velocity (you probably will be), you can load up 3-5rds from .005-.030 off and see what seating depth is best.
    If you're at a good velocity and it's looking good on paper, don't mess with it. Learn load development on another barrel, because there will be plenty in your lifetime that don't shoot out of gate.
     
    AJC likes this.
  16. savagedasher

    savagedasher

    Joined:
    Jul 25, 2012
    Messages:
    6,861
    I do powder change and use seating depth to lower the Es
    Then I tune with a tuner
     
  17. Fast14riot

    Fast14riot Silver $$ Contributor

    Joined:
    Aug 21, 2013
    Messages:
    820
    I do seating depth first to also fire form some brass for charge weight testing. This is how I work up loads for my AI chambers.
     
    AJC likes this.
  18. Ned Ludd

    Ned Ludd Silver $$ Contributor

    Joined:
    May 28, 2012
    Messages:
    2,449
    IF you have sufficient freebore to seat them optimally, a 7-twist barrel is all you need for 90 VLDs. Typically, you want at least 0.169" (or longer). IMO, much of the information about VLDs being difficult to tune is a myth. I've shot the 90s for years and they tune in as easily a any bullet I've ever used. In my hands, they will shoot bugholes at around .005" into the lands, or around .018" to .021" off the lands.

    You can certainly try the Berger VLD seating depth testing guide, but remember, it was intended for use as a very crude guide to cover a wide range so as to find a coarse seating depth region that can subsequently be tested in finer increments. The issues with this approach are that:

    1) You are moving the bullet far enough in/out of the neck that effective case volume and pressure can change appreciably, thus potentially altering optimal charge weight

    2) Moving a bullet that far (~ 1/2 the total length of the neck in a .223 Rem) is not realistic for a competition rifle with a "known" chamber/throat. If the throat is cut with optimal freebore for a given bullet and you try to move the bullet in/out that far, it totally defeats the purpose.

    The Berger VLD seating depth guide can be very useful when more common approaches fail, but I would generally not start there with a competition rifle set up to shoot a specific weight range of bullets (i.e. throated for a specific length bullet length range).

    My advice would also be not to mess around initially with bullets you don't intend to use. For comparative purposes, that would be of little use as every bullet may exhibit its own distinct behavior with regard to seating depth preferences. Comparing one to another is comparing apples to oranges.

    Pick one or two bullets you would like to use, and optimize charge weight with the bullet seated at about .015" off the lands. Once you are satisfied with your charge weight, test seating depths from .003" to .027" off the lands. Note that the initial .015" off seating depth is exactly in the middle of the total range. That means you're not moving the bullet more than half the overall range in either direction. Thus, the impact of changing seating depth on effective case volume and pressure are of minimal concern (i.e. - only moving the bullet .012" in either direction from the seating depth at which you optimized charge weight is usually not enough to markedly change pressure/velocity. In my hands, this approach has worked with almost every bullet I have ever used, including 90 VLDs. The notion that VLD bullets are always finicky or hard to tune just doesn't seem to hold up in practice in my hands.

    If you are still not satisfied with the precision, then try seating depths of "touching", .003", .006", and .009" into the lands. Depending on the cartridge, I typically back the charge weight off a tenth or two before seating bullets into the lands, to minimize the chances of pressure spikes. You can always come back and fine tune charge weight again for velocity/grouping at the end if necessary.

    Finally, it is usually possible to get someone on this site to share first hand information regarding seating depth preferences for any given bullet to use as a rough guide or starting point. However, if you're using a bullet for which you have no idea whatsoever of where it may want to be seated, there is nothing wrong with using a slightly reduced charge weight and testing seating depth first in fairly coarse increments to find approximately where it wants to tune in. For example, I might try .010" and .005" into the lands, "touching", and from .005" to .030" off the lands in .005" increments, using 3-shots only per seating depth as a quick and dirty way to find a decent seating depth start point for charge weight testing. After charge weight optimization, I would then go back and test seating depth in finer increments (.003") as I described above, focusing especially on the region of the initial coarse test where they appeared to shoot well.

    The bottom line is that there are a variety of paths you can choose and still end up with the same final load. After going through various approaches, you will likely pick one you feel is most suitable for your applications and stick with it as a starting approach from there on out. It's only after going through what I know usually works without success that I'm motivated enough to try other perhaps more "extreme" approaches.
     
    Last edited: Jan 11, 2019
    Boatschool02, AJC and Whit holman like this.

Share This Page