COAL changing for no apparent reason?

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  • COAL changing for no apparent reason?

    I made 25 hand loads today with my Lee Challenger Breach Block press and RCBS seating dies today. I set the bullet seater to give exactly 57.5mm as a total COAL (not from ogive). All the nuts on the die were nipped up and there was no slop in anything. No what confused me was I kept getting different COAL measurements! Not huge variation but one would be 57.6 then 57.2 then 57.3 etc... I thought the projies might be varying in length but I measured 10 and they only has a .02mm varience so the change in COAL was coming from somewhere else.

    I don't have a comparator to measure of the ogive but does what I've described as a +/- 0.5mm variance par for the course with my setup? I was wondering if the cases could affect it but I don't see how... any ideas?

  • #2
    What you are "probably encountering in my biased I hate RCBS dies reactionary mind ignoring logic is runout. Two factors are at play, the strength of the press and the concentric nature of its action coupled with the quality of the dies. I am not a fan of RCBS dies so before I go on a rant on their excessive runout I'll stop there. (They would be your main issue in my opinion)

    A previous rant alluding to the issue you have encountered, due to my reply further down the thread...:
    http://shootingaustralia.net/forum/reloading/1724-a-good-basic-reloading-kit-beginners

    See Jasmays logical post below

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      A previous rant alluding to the issue you have encountered:
      http://shootingaustralia.net/forum/reloading/1724-a-good-basic-reloading-kit-beginners

  • #3
    I'm loading .222 here. Mainly using the brass from the 5 or 6 packets of factory ammo that I purchased when I first purchased the gun. I also have some unfired Winny brass that I will get to once I've got a bit more au fait with the whole process. I have only heard the term 'run out' be applied to a circular item not spinning on its dead center axis on a lathe. Primer depth cloud definitely have something to do with it, I found the Lee hand primer tool to be quite difficult so squeeze on some cases while not at all on others. All my dies are RCBS. Honestly I'm surprised that they could be the issue? they seem very sturdy to me but then again I've never seen a Redding or Forster so I'm not qualified to comment on the difference.

    All the cases were either slightly undersized or trimmed to length using the Lee trimmer tool then internally and externally chamfered with the Lee tool. I also have a RCBS 10-10 beam scale on it's way (so if anyone wants a perfect condition cheap Lee Safety Scale PM me ($40 shipped)).

    Can you please explain how neck dimensions/tightness can effect the seating depth once the cases have been neck sized? Isn't neck sizing supposed to remove that issue entirely? the cases are twice fired, once with the factory load, then with the lightest load in the ADI handbook for the powder and projectile I was using.

    I'm located in South Eastern Melbourne.

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    • jasmay
      jasmay commented
      Editing a comment
      Originally posted by Remo" post=24932

      Can you please explain how neck dimensions/tightness can effect the seating depth once the cases have been neck sized? Isn't neck sizing supposed to remove that issue entirely? the cases are twice fired, once with the factory load, then with the lightest load in the ADI handbook for the powder and projectile I was using.
      There is usually some small (Sometimes large depending on brass quality) inconsitcney in neck wall thickness meaning if all cases are sized to the same OD they can have a varying ID, as well as this, the more firings cases have on them they begin to work harden, and can do so inconsistently accross a batch, all this means different forces applied during the seating process which can give some crazy dimensional outcomes.

  • #4
    Is your seating die clean. Every so often you should swab/blast your dies with some brake cleaner to remove dirt, lead, alox or any number of filthy bits.

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    • #5
      I'm going to load a few tonight. 1st I will make sure all the primers are seated below the face and put the press on a stronger table (yep Crab my table flexes as well). I also purchased some new Mitutoyo 500-196-20 verniers which I highly recommend. They hold zero like a champ and are 1000 x better than my old $30 pair which used to wander all over the place. I'll post back tonight with the results. Cheers.

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        I was looking at adding a reinforcing plate under my table or adding a vertical support directly under the press. I had a tinker with mine last night but i got all excited and started making more .45 bullets instead

    • #6
      Originally posted by Remo" post=24837
      I made 25 hand loads today with my Lee Challenger Breach Block press and RCBS seating dies today. I set the bullet seater to give exactly 57.5mm as a total COAL (not from ogive). All the nuts on the die were nipped up and there was no slop in anything. No what confused me was I kept getting different COAL measurements! Not huge variation but one would be 57.6 then 57.2 then 57.3 etc... I thought the projies might be varying in length but I measured 10 and they only has a .02mm varience so the change in COAL was coming from somewhere else.

      I don't have a comparator to measure of the ogive but does what I've described as a +/- 0.5mm variance par for the course with my setup? I was wondering if the cases could affect it but I don't see how... any ideas?
      the seating die pushes on the ogive of the projectile, the die uses a funnel shape to center and seat the projectile and it is designed with a universal shape to fit all projectiles.

      If you are using hollow points or some other projectiles with a thin soft jacket the die can depress or deform the projectile ogive slightly during seating.
      or Perhaps the projectiles ogive is not uniform.
      or as the seating dies presses on the ogive there is an inconsistency with the tip of the projectile like a burr.



      .

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      • #7
        I started loading recently with a Lee Challenger Lock press on a stable and secure surface with mounting plate reinforcing under it as well and I get minor variations using Hornady SST 150 projectiles.
        My vernier is a steel digital and seems accurate enough ( done some engineering in past life so qualified to judge some tools ).
        My dies are RCBS and fit in the Lee Interrupted thread adapter and there is some slop in the lock tab and the adapter thread itself is no machine fit by any means.
        All up a few thou would be standard I M H O Gestimation for this sort of mechanical set up.
        It is definitely not a hot cold press fit piece of machining but certainly adequate for the average loader to start with.
        To test for variation with out guages put a coin or better flat mild steel washer in the space between the top of the ram and the die base and then press down on the top of the die while you work the lever enough to move the die up -- at a guess I can see movement of at least five and possibly as much as ten thou between the die holder and the press body itself. If you put the pressure on one side of the holder only you will see lateral movement as well.
        I imagine the die will find its position each time it is used and the variation in shell neck tension while seating the projectile will show up as a result in the overall lenght.
        I measure with a comparator as I think it will be more accurate that way but even it wont prevent the slop factor creeping in between each press stroke.
        A good post though and lots of information learned for me --all good. .

        A week or so back I learned that Hornady SST Ammo has crimped primers -- after I buggered three working it out.
        Made a deburring tool from a flat file handle ground to fit and its easy enough to clear the bur after de_priming the shells (30.
        Another trap for new players solved
        [center]
        Don’t poke the snake, walk around it and come back later with a double-barrelled shotgun and blow its [email protected]#!ing head off!.

        Australia in future, the outcome is the same, a bloody dictatorship run on the whims of a very few ego-centric pathological elitists.

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        • #8
          There's a few reason of which some have been mentioned already.

          Projectiles variations from ogive to tip. (Double check. You could just find or drill a hole that is close ogive for a rough check device).
          Neck tension. (Turning may or may not improve the issue, too many other variables though. Runout being a bigger problem here).
          Sizing grease in the case neck. (Be sure to clean them before seating).
          Seating stem to projectile contact. (The stem may not be fitting projy consistently due to either stem or projys)
          Press leverage, ie. where you stop on the stroke / how hard you push on the end of the stroke (critical with breech or turret presses).
          Press. (Slop in leverages and ram, alignment with ram and die threads).
          Dies. (Quality and/or design).
          Calipers. (Quality and/or repeatability).
          And believe it or not the compression of air within the case- (which neck tension can direct attribute to this issue).

          I don't totally agree with NF in regards to the LEE breech lock setup. When you preload the dies as per LEE instructions, the 'slop' is removed so that your end dimensions should be consistent. Not necessarily giving true and concentric ammo but consistent nonetheless. I use a LEE presses, breech locking and a turret, for most of my hunting rifles. I get consistent OAL and runout. I do ensure my prep is consistent all the way though and it took a little time to get the results I was wanting.
          Being that the ram presses on the shell holder and that against the die and the die against the threads of the press in most setups, there will always be an amount of 'slop'. Setting the die so that when you raise the ram to the point that you can consistently remove the slop and repeat the same handle position with the leverage is vital. A LEE crimp die could also assist you but you'd have to restart your load development and ensure the die is set up correctly so that you get the same tension each pull of the handle.
          Another suggestion would be to raise the ram to seat the projy, lower ram, then turn the case 90 degrees and raise the ram again.
          Just to eliminate the caliper as being the culprit, re zero it each time before measuring a few to check its repeatability.
          Load other rounds in the same setup or use different projys to see if the issue is occurring with all reloads.

          For a comparison though... I loaded a lot of Lapua Scenars and Berger VLDs into Lapua 6.5x47 cases with Wilson and Hornady dies the other night. (My point being that I was using quality component in quality dies).
          The OAL lengths were measuring a few thou different even though I had batched everything, weight etc.
          However I wasn't concerned the least as the distance or relationship between the projy to the lands of the rifle were all exactly the same.
          This is what is most important!
          If you can buy yourself a tool or device even as the simple Sinclair comparator nuts to measure the ogive to base length I think you feel happier in your reloads. I doubt the difference will be as great as the OAL measurements are. If you can't afford such a device, drill a hole as true as you can in a piece of steel and as close to the caliber you're using and insert the projy and measure the base to the steel to check uniformity. This will help you batch lots if they are varying by a few thou too much.

          Anyway, keep us updated to how you get on and I hope I may have given you some ideas of where to start your process of elimination!

          Cheers.

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          • #9
            Ok I've solved the problem. After the help here and more google-fu I thought I'd try the deadstop method. Having a mini lathe is great for things like this. I spun up a simple thick aluminum washer and used it when I set the bullet seating depth. The result was +/- .03mm of my target COAL. I'm more than happy with that as most of that would be projectile length variation.

            I am guessing the slop in the press and or the press stroke pressure was causing the bigger COAL variations I was getting. I've not bothered measuring projectile run out as yet but I have neck turned a few cases on the lathe to see how much variation there is in neck thickness (and there is definitely a few thou in all of them).

            How even is are the neck thicknesses of Norma and the other very expensive brass makers? I'm thinking I will fire all the cases I have 5 or 6 times and then just turf/give them to someone here and buy 100 Norma's and start again.

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              Lapua Make 222 cases, they are the best in the world and cheaper than some norma cases, 222 included. They are worth the $89/100. Norma is up there, but its no Lapua, but then again both have very consistent necks, what brand are you currently using?

              BRT for price indication

          • #10
            FRom some old magazine some where I recall that one of the reasons for the 222 being a great bench rifle was the long case neck sets the projectile up pretty much square on via the length inside the case.
            Looking at the lee Press and the adapter collar and there is a heap of side slop via the adapter threads.
            Some can be counteracted by lightly seating and then turning the shell 180 degrees before a second stroke to final finish it.

            If you are a dab hand with the mini lathe and some threading tools it would be easy enough to find the flats on the adapter and then from the sides drill three equidistant small holes in the press itself , probably say one third down the adapter.
            Thread and insert three hex head High tensile Allen screws into the press and into a small locating depression drilled into the smooth faces on the the adapter.
            The adapter must be held down very firm while milling all this.
            Once its done simply lock the adapter via the three screws and all the slop will be gone.
            Use pointed locking screws similar to bearing fasteners but with a point to mate into the drilled spot on the adapter.
            Alternately machine or grind points rather than the grip end these screws often have
            If your dab hand enough and your adapter was say five thou high [with a spacer washer ] when you drilled it then when assembled with out the spacer pointed end of the grub screws will pull it down tight due to the five thou off center vertical difference and even as well as centered and it won`t shift ever .
            Check a few loads for run out and when you find that center point keep a dummy load for reference.
            IF you need to reset u for some reason just use the dummy load to relocate you center.
            I would do it if I had the lathe because I like fiddling with things but I don`t have the lathe and so I won t be doing it.
            Worth a try IMHO jsut for the fun of creating things that work.
            Fiddly to use but once its set up probably worth it and nothing to loose -- just use only small say eighth inch or less grub screws so as not to weaken the frame of the press [ Half inch bolts will NOT do
            [center]
            Don’t poke the snake, walk around it and come back later with a double-barrelled shotgun and blow its [email protected]#!ing head off!.

            Australia in future, the outcome is the same, a bloody dictatorship run on the whims of a very few ego-centric pathological elitists.

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            • #11
              From what I have read on this entire post, I would say, the quality of the projectiles is the issue. Variations in projectile OAL, and Ogive shape would be the issue. Not an issue for hunting grade ammo, but for serious accuracy nuts, it can cause them to show OCD tendencies.

              Reloading die brands have different features will aid in getting a consistent COAL. Pay the big bucks and get a quality competition seating die, and pay the big bucks for quality match grade projectiles, and buy bulk of the same batch if you are truly serious.

              Just a few points to ponder...

              Thanks,

              Oddball

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