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243 pressure issues

Discussion in 'Handloading and Reloading' started by boardmstr, Feb 17, 2012.

  1. boardmstr

    boardmstr Member

    i apologize for the long post, and let me thank you in advance for taking the time to help/share your knowledge. i want to clearly explain every little detail in order to help narrow down the cause of this problem. i am fairly new to reloading as i have only been in it only one year and have only gotten my information through reloading manuals as well as forms like this. i understand that despite hundreds of hours researching the subject of reloading, it doesnt leave me much more than tired and having to sort through the true and speculated information. i have reloaded a few thousand rifel/pistol rounds without any issue but have recently run into an issue while trying to reload 243 win for my girlfriend's savage 99e. I started reloading for this rifel when the reloads (unknown recipe) she was shooting from an experienced family friend started splitting the cases in half approx .365" up from the base of the cartrige on two occasions.

    load #1) I started with clean mixed once fired brass (primarily rp and win) all trimed to 2.035" and used a rcbs 243win die, and started loads straight out of the hornady reloading manual 8th edition for the correct bullet (100 gr sp interlock 243). All these loads used fed 210 primer per hornady. I started with 31.5 gr imr 4064 and a col of the published 2.630" with a very very slight crimp. when i went to test these rounds, i found that on occasion some cases were again separating in half in the same spot as the other reloads, and sometimes the primers would back out or flatten or both. other times the cases seemed fine, other than a shiny stress line all the way around and sometimes a fracture 2/3 or all the way around the case would show in the same spot the cases were splitting.

    after this i measured the headspace using a resized trimmed case that i cut a slit into the neck and just slightly seated the 100 gr interlock and chambered the uncharged/unprimed round to measure where the bullet be pushed back in the case and would contact the lands. the col of this test was 2.810" which i assume to be a bit long.

    I then reloaded a few different loads of different amounts of imr 4064with several col for each change of powder weight. all of these loads produced similar results indicating high pressure. all loaded brass was checked and the correct size in all dimensions. each powder charge was hand weighed on a rcbs manual scale calibrated correctly. none of the following reloads had any crimp.

    all loads used once fired mixed brass cleaned and trimmed (after resizing) to 2.035" using imr 4064 and fed 210 primers in the same rcbs dies on a single stage rockchucker.

    #2) 31.5gr, col 2.710" fired 3 rounds, one primer flattened and backed out slightly, the other 4 had slightly flattened primers and all 5 have small dimples rising up from bolt face and all are slightly cratered around firing pin dent

    #3) 31.5 gr, col 2.805" fired one round, flattened primer with cratering and split the case in two separate pieces. didnt want to fire the rest of these.

    #4) 32.6 gr, col 2.633", 3 rounds. backed out primers with very slight cratering. all had stress line all the way around cases.

    #5)32.6 gr, col 2.710", 3 round. all backed out primers. two with slight cratering and one with more obvious cratering, all had lines around case which were less visible than load #4.

    #6)32.6 gr, col 2.810", 3 rounds. one backed out primer and cratering with stress line around case, two flattened primers with cratering, one with cracked case 2/3 around and one with two stress lines all the way around case. the first was in the same .365" up and the second was .665" up from the bottom.

    #7)34.2 gr, col 2.633" 3 rounds. all flattened primers with cratering, all with stress lines at .365"up from base

    #8)34.2 gr, col 2.710" 2 rounds. two flattened primers with cratering, one of which was backed out.

    #9)34.2 gr, col 2.810" 2 rounds. both had flattened primers with cratering and one had cracked case all the way around in same spot as others, the other case had a stress line around case in same spot.

    the min published load with imr 4064 per hdy is 31.0 gr and i started with 31.5 gr. and went up from there to max load of 34.2 gr. my original thought was that the .2" gap the bullets traveled was causing a pressure spike when they would hit the lands but changing the col didnt help even with the col set to 2.810" where the bullet is just touching. or for some reason there was some sort of under pressure issues causing the backed out primers. i got confused by the flattened primers and the backed out primers as well as the splitting cases as t thought they showed contradicting signs. before i start over with cci primers and/or different powder and risk blowing myself up anymore i'll wait to see what you kind folks can come up with (which i should have done in the first place). and yes i realize that this was dangerous testing these loads now that i know my original suspicions were incorrect.

    thank you so much and any help would be greatly appreciated as well as needed. dont be afraid to hurt my feelings as i am open to learn any way i can.
  2. Longhorn 76

    Longhorn 76 Well-Known Member

    You are not properly measuring the headspace with your method, but the freebore (or distance of bullet off of the rifling).
  3. boardmstr

    boardmstr Member

    thanks for the heads up longhorn. thats something i read about on another forum but i guess it wasnt too accurate. the reccomended col from hornady was used in the origional load that first brought the problem to my attention. i forgot to mention that the rifle shoots fine with factory loads.
  4. steve4102

    steve4102 Well-Known Member

    Headspace is not the distance to the lands with seated bullet. It is the distance from the bolt face to the datum line in the chamber.

    You have issues with that rifle and I recommend you stop shooting it until you get them repaired.

    Backed out primers can be a sign of a Low pressure round. Backed out primers can also be a sign of excess headspace in the rifles chamber. Split cases with mild loads is also a sign of excess headspace. IMHO that rifle has excess headspace issues and should not be fired again until it is checked out by a qualified Smith and repaired.
  5. helotaxi

    helotaxi Well-Known Member

    The rifle either has excess headspace OR the reloaded rounds have the shoulder set back too far. Regardless, the resultant issue is excess headspace which will cause all the the issues you have described.
  6. boardmstr

    boardmstr Member

    thanks guys! anyone know of a decent smith in northern ca? the closer to the bay area the better!
  7. Strongbad

    Strongbad Well-Known Member

    Where did the brass come from? How many times has it been reloaded? The splitting could very well be from excessive resizing and the web of the case is thinning out. If you've got a bunch of reloads on these or it's range brass etc. this could be contributing to your problem. If the chamber was a bit on the generous side that would certainly exacerbate the problem.
  8. NCsmitty

    NCsmitty Well-Known Member

    I agree, you may have more to worry about than COAL. It may be the action is sprung and is showing headspace issues, or the lever lockup has wear. You need to have that checked.

    If you combine that with brass that may have had the shoulder pushed back a bit too much when sizing, you'll experience consistent head separations.
    Your initial loads do not even meet www.hodgdon.com start load specs of 33gr of IMR4064 under a 100gr bullets.
    Something isn't right.

  9. gamestalker

    gamestalker member

    It probably has to do with how much head space is being created during resizing, which would be too much. You should only be resizing the case enough to bring the neck into spec. and no more than is necessary to facilitate normal chambering. If the brass will chamber normal after having been fired, only adjust the resizing die to allow for neck sizing. If it doesn't chamber normal and is too tight, adjust the die down in very small increments until chambering does not create unusual or abnormal resistence.
  10. rcmodel

    rcmodel Member in memoriam

    It's O.K. with factory loads.
    Breaks cases in half & flattens primers with your reloads.

    You are pushing the shoulder back too far with your sizing die adjusted like it is now.

    SO, you have created artificial excess headspace.

    The primers are backing out when the pressure builds in the primer pocket.

    Then the powder lights, the pressure builds, the case expands, grips the chamber and stretches until it cracks & breaks.
    That slams the rear of the case back into the bolt and flattens the primers.

    You need to back off your sizing die until the rifles bolt will just close on a sized case with slight resistance.

    Last edited: Feb 17, 2012
  11. 243winxb

    243winxb Well-Known Member

  12. ranger335v

    ranger335v Well-Known Member

    RC is absolutely correct.

    Headspace is almost irrelivant if a handloader understands how to correctly adjust his FL sizer.
  13. rcmodel

    rcmodel Member in memoriam

    Case life is not very good on a Savage 99 under the best of circumstances.

    The rear locking bolt allows a lot of action & case stretch even when the case is sized to fit the chamber.

  14. boardmstr

    boardmstr Member

    thanks folks. and strongbad- all the brass was once fired im pretty sure all out of that same gun.
  15. 243winxb

    243winxb Well-Known Member

    Then firearm needs to see a gun smith to have the headspace checked. There can be case head separations on the first firing of factory ammo, if there is excessive headspace.
  16. Centaur 1

    Centaur 1 Well-Known Member

  17. kingmt

    kingmt Well-Known Member

    Once fired then NS or FL sized?
  18. boardmstr

    boardmstr Member

    all brass was once fired and then FL sized to where the die was touchong the shell holder at the top of its stroke. actually when the shell holder had camed over from the top of its stroke. thanks Centaur 1. that was going to be my next question. it is a great feeling to have the assistance from so many people here. i wish everyone in the world was as helpfull to others.

    my next questions are... when i resized these cases, i did about 300 of them at the same time and primed them as well so once i found an accurate load i could load up a bunch. i guess all those are trash now? or just give them to my girlfriends dad to shoot out of his 243s? i dont want to fire form them back with these kinds of pressure signs.

    also, this 243 is a lever gun, which to my understanding has less mechanical advantage than bolt action. is it very dangerous to just neck size when reloading for a lever action? the last thing i want is to have a round not chamber all the way when a 300lb boar is charging my girlfriend? although that could be better than having chunks of metal and hou gasses flying in her face from too much headspace.
    Last edited: Feb 18, 2012
  19. Striker Fired

    Striker Fired Well-Known Member

    Load up a small batch for your girlfriends dad that fit in his gun and see if they show pressure signs in there.That would tell you if it's your gun,the brass,or die set-up.I would try to make sure that the shoulder isn't too far back for his rifle though.Do you have a factory round that you could compare the shoulder placement with? Not a real good stand in for a headspace gage but it should get you very close.Mostly you would want to see if it is pushed back farther than the factory round. If it is DON'T SHOOT THEM.
  20. Centaur 1

    Centaur 1 Well-Known Member

    Look up how to make loads for fireforming brass. I've never done it, but you can find information how to do it. I'm sure that you could use the same procedure for this brass that you would use if you rechambered the rifle to an ackley improved caliber. I've read where guys will use a mild charge of pistol powder, and top it with stuff like cream of wheat. Just enough pressure to move the brass back were it needs to be without building excess pressure.

    You won't be neck sizing unless you buy a neck sizing die. Use the full length die that you have, and use the instructions that I posted. Even if you don't push the shoulder back any, the FL die will still size the body of the shell. When I load for my lever action I adjust the die so it just kisses the shoulder and there is never any trouble with cartridges sticking in the chamber.

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