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Thread: Rumbler, thanks for the explanations of "WHY"

  1. #1
    Join Date
    Aug 2012

    Smile Rumbler, thanks for the explanations of "WHY"

    I'll miss Rumbler, and asking him questions and getting his responses and the reasons behind them.
    He helped me understand some of the aspects of reloading I hadn't considered before.

    These are taken from my PM's with him and maybe they will help others as well.

    ANY LOAD DATA contained, is to be considered over max, and loads should be worked up in the users guns., remember, we ARE talking about Rumbler.

    About minimum powder selections for my uses.

    Quote Originally Posted by Rumbler
    I think that you nailed it. Seems you have done your homework.

    Quote Originally Posted by mapper
    I am trying to keep it simple on the powders and at a semi minimum..

    With 38/357, 9 mm, 45 acp, 222,223,243,6mm, 308 to load for.

    And understanding I don't shoot much 357, a lot more 38 are shot and loaded..

    Would the following powder list pretty much cover all bases from light varmint rounds, to plinking ammo, to hunting rounds to precision rounds in both pistol, rifle, and revolver...
    Yes I understand that there may be a better powder choice for a paticular caliber, but mainly looking for good usable loads..with good data in the sierra, lyman, and lee books that I have, and standards for typical highpower loads.

    The list..
    38/9/45. Bullseye
    357. 2400
    222 and lighter than 69 gr 223 h335
    Heavy 223, as well as the other calibers 243, 6 mm, 308
    Reloder 15, imr 4895, varget

    About new lc brass I had, and whether I should put a slight chamfer on it.

    Quote Originally Posted by Rumbler
    No, I would not chamfer the primer pockets on the new brass. Remember your goal when you "fix" the crimp on used brass; make the pocket have straight perpendicular walls top to bottom.

    Further, because of variances - even lot to lot - in new same manufacturer brass, I would back off the powder charge you already established a couple of tenths and redevelop from there. Incorporate your tweaks into the new brass, because you already know the data that makes your "old" brass work well. So in the future as you go back to that brass you can have a high level of confidence that your existing data is safe, and the profile of its performance.

    Make sense?

    Quote Originally Posted by mapper
    The brass came today..
    Looks good,.on the primer pockets it is straight, no chamfer. Looks like all I have seen is lc 13 stamped..

    Now for the question of the day.....
    Do I put a slight chamfer in the primer pocket..

    I plan on sizing, trimming them before I load any..

    I may tweak the load a little, velocity at same place as with fed primer
    25.5 varget..smk 77 mag length..

    But with a cci magnum primer....
    Remember in that link, same cup thickness and primer composition as military primer, but a little more sensitive due to a diffrent anvil than the military ones..

    Purpose of this will be a good mag length match round that works well in a bolt gun as well..

    I'll try diffrent seating depth games with the 80 smk's as they are single load anyway..

    2nd question, would you work the tweaks in the load up with my other lc brass that has been 2-3 x fired.. then when I'm happy, load 500 of these..
    Remember this is new brass..
    This is pertaining to OAL in 300 blackout and getting near lands.

    Quote Originally Posted by Rumbler
    No, I don't think that you will get near the lands running 2.260, but you are certainly going to find that a tight fit in most poodle shooter magazines.

    Quote Originally Posted by mapper
    Only asking,master yoda-san, as the hornady guage is sold out, no backorder..and I am aware of the use of a collet necksizing of the case and threading the flashole..
    Id rather a 0.002 bump off fired size as I don't like to work brass anymore than nesessary.

    So the there is no way you'll get near the lands running 2.260 oal in 110-208 gr weights untill you find or make the guage answer is good..

    I wishh han solo would get his ass here with my bolt and chamber guage..but I could load a little ammo so I'll have some fired brass to set the dies up with while I am waiting..
    Probabally some 147/150 pulls to start with..
    Obi no nothing
    Quote Originally Posted by Rumbler
    yes I have. And even further with light bullets in the 100-125gr range.

    And yes, on average I bump the shoulder back .002-.003 for the autoloader. I have yet to fire my handi-rifle, so i have no idea what it is going to tolerate . . . or not. But those numbers work quite well for my CMMG barreled poodle shooter.

    . .and yes, the right answer is indeed "is six bucks really worth not knowing for sure". But obviously you already know that so I won't pester you about it.

    Quote Originally Posted by mapper
    Have you found this to be the case 1.73+/- to get anywhere near lands measured from case to ogive?
    Or do I need to either pick up or modify a stoney point guage to check it?
    And yes I do know the answer to the ?, "is six bucks really worth not knowing for sure"

    Also how much do you bump the shoulders back off fired brass..typical 0.003 for autoloader?

    Still waiting on the millinium falcon to deliver the bolt and chamber guage..
    Obi no nothing

    Discussion about working a load up

    Quote Originally Posted by Rumbler
    I mostly just use voodoo.

    No, seriously, some might call it voodoo, but in reality it is spending the time thinking through what I want to accomplish in a particular load, then a combination of published resources, experience gained by making previous mistakes, and patience in testing.

    Patience in testing may be the single most important component behind doing enough research to learn if the powder you think will work, will actually fit the performance criteria you want/need.

    I believe it would take an awful lot of words to cover even most of the major concepts, mid level concerns, and finite tuning techniques. Then there is addressing these things and their level of concern related to what type of ammunition you want to produce; hunting, self defense, benchrest accuracy, 'cheap range plinking', etc. Then there is; gas gun, single shot, bolt action variants and their "needs".

    Heck it took me several weeks and dozens of rounds JUST to figure out what the best bullet jump was for my Remmy 700. Obviously someone just wanting to create plinking ammo, OR someone wanting match level ammo for their magazine fed gas gun wouldn't have any interest in that process.

    Huuummmm. Publishing something like this sounds like a project for a guy who is laid up for several weeks trying to get their feet back under them after starting a course of liver treatment drugs that has kicked their butt.

    Quote Originally Posted by mapper
    Mike, I have seen a few diffrent ways to do this from shooting through chronos and looking at velocity and sd, to dan newberry's optimum charge weight, to ladder tests, to going in 0.5 gr steps, to going in finer steps, to marking pills with magic marker and seeing where the residual color prints on the target, to reading primers, to downright voodo... to work a load up...

    But I haven't seen it explained in a reload was kind of glossed over..

    With the interest in loading on this forum, for which I'm thankful for, to the amount of new folks getting into it,
    I would like to see a good thread on it.. I am just a apprentice mage at this.. no jedi master..only been doing it a year..
    So I am not worthy of creating the thread...

    So...jedi master... can you guide the rebels to the force?
    Load development continued:

    Quote Originally Posted by Rumbler
    Ya know, I have actually started working on that project. Dang, just figuring out how to lay out several levels of knowledge applicable based on the (loading) interest of the reader without being extremely repetitive in body test is no small hurdle to figure out how to cross.

    There was recent question posted and is an excellent example. He wants "the most accurate ammo he can make" and another guy just needs to know what to do to make .308 that fits in their dagum magazine and chamber so they can go blast away making tons of noise and buckshot like groups at 25 yards.

    It's tough. But I really do believe I'm getting a handle on it.

    Quote Originally Posted by mapper
    I really am serious about the newer reloaders here from benefiting of the knowledge...
    It took me some time and research to discover some of it...
    And I'm just scratching the surface...
    As they say in field of dreams...
    People will come....oh people will come..
    I guess the more I find out, the more I want a in depth, "this is why" answer...
    Not a glossing over...sure it will weed out the non serious student, and make the serious student dig deeper....
    But how many times did you end up figuring things out by going " hmm...and knowing the right way to approach a problem, knowing the constraints that you must work within?

    That kind of knowledge is important..and hard to come by..
    Just sayin'. And stuff..

    Quote Originally Posted by Rumbler
    I'm pretty sure you would wind up with some excellent match ammo!

    I tried to dumb it down some because I know that:

    A) Some guys are young and they suffer from young guy syndrome, they don't have a lot of patience for finite measurements.

    b) I suspect they will go to harbor Freight to get a vernier caliper.

    Quote Originally Posted by mapper
    I'll let the jedi masters tap into the force to answer this one....
    As I'm just a 2nd year apprentice mage... I had nothing to do with this..honest..4

    But I know what I would do....
    I would take fired brass from the rifle, and measure the case-shoulder dimension
    And adjust the dies to bump the shoulder back 0.002, then take a oal guage to determine the case -ogive dimension where bullet hits lands and record that.. then back off 0.020 to start if not concerned with feeding in magazine...

    If mag fed, that would determine seating depth...

    Then I would try to do some research as what the components that highpower shooters have had sucess with...
    And for me that would probabally be 4895, 4064,re 15, varget for powders..

    I would start in the middle of the charge weight, load 5, then go up a couple tenths charge weight, load 5, etc..until max charge...
    And have a general idea that a lot of match ammo is 2600-2650 fps, but would not rely wholly on that as shoulder fired rifles it is not uncommon to see variations in velocity..

    I would hang a target at 100 yds, and shoot for groups through the chrono, making notes of velocity and sd and es..for good nodes of accuracy, then seeing it fall off, as long as there were no signs of overpressure..

    I would take the charge weights up to the point of starting to see primer flattening...
    Then I would try to tune seating depth on the next load test...

    If I was happy with accuracy, I would quit, if not i would try another powder...
    And go through it again..

    The 2nd year apprentice mage...
    Powder position in case and velocity
    Quote Originally Posted by Rumbler
    Mapper, just something to keep in mind . . .

    The AA #5 load listed for .357 magnum is 3.4 grains. Advertised velocity is 1280 FPS with the bullets I was using. I made up six and chronographed them:

    1) 1240
    2) 875
    3) 750
    4) 1250
    5) 675
    6) 1255

    So . . what changed? Answer: The powder position inside the case. But it is/was a listed "standard" load. I switched to HS-6, and couldn't get 30FPS variance to save my soul.

    All I'm saying is: trust the chronograph and reading the brass, not the manufacturers load recommendations.
    Last edited by mapper; October 21st, 2015 at 05:32 PM.

  2. #2
    Really good info Mapper. One of the questions I always have, is what powder to use. I know the books give you advice, but there are times when reading, people have favorites or different powders. Same thing with primers, bullets and brass. There's so much to learn and so little time. lol

  3. #3
    Join Date
    Aug 2012
    Generally let the rifle tell you what it likes.
    As far as 308 loads for the 168's and 175's you are going to be shooting, those have been shot in hi power competition for years.
    There are replications of federal gold medal match I think in a 308 loads at work titled thread.

    4895,4064,reloder 15, and varget would all be choices for those, and probally 4166 as well.

    The interesting part is in a 223 and the choices relating to bullet weight.
    The heavy bullets I would try with the slower powders
    The lighter ones with the faster ones.
    Say 45-77 gr spread.
    Light ones probally 4198,335,
    Mid weight benchmark, blc-2,tac
    Heavy weight varget.4064,cfe 223 or something in that speed.

    I'm still volumes and powders in things very close to what I'm playing with.
    This is worth looking at.

    I have that mongoose and mongoose load data as well as 6x45 data to pull from.

    Worthwhile read on primer, both cup thickness, pressure and brisance( hotness/flash) as well as diffrences between a commercial and military primer.
    Last edited by mapper; April 5th, 2017 at 04:02 PM.

  4. #4
    I started saving my 5.56 casings. That's going to be my next project, after I'm done with 308 win and 6.5 creed. In the 6mm forum, looking at the primer test. I saw how similar, the cheap, Winchester LR, is at igniting/burning to the more expensive Federal 210M. To my surprise, I seen many people recommending CCI primers, and in the test, it look a lot less powerful ,than the Federal and the Winchester. I have 1k of the CCI and 200 Winchester LR. I hope the CCI perform better that it look on the Pic.

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