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#26
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I think the OP would be much better off to start with one bullet to learn reloading. Do not start off trying to develope a load for four or five different bullets at the same time. I would have suggested starting with a 124 grain RN. It would be the most likely to feed with no problems. A beginner does not need to try and develope a load while at the same time try to diagnose feeding problems.
Get one load working, shoot a couple hundred of them, then move on to a new bullet.
__________________
Don't believe anything you hear and only half of what you see. USPSA A-27738 Allan |
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#27
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It's not the said nomenclature, per se, that I have a problem with. Rather it's the conflicting ideas or jargon that I'm come across which get frustrating. For example. I see COL [which I'm going to stick with using since it's an actual proper acronym] when 72 hours ago I learned it as oal. Or that I was told previously that Bullet type (shape) is not a factor when determining the proper powder charge and later I'm being told it's crucial. Using MY brain, I feel it's not for the simple reason that COL is what it is despite the overall length of the bullet and or it's shape. Since bullet weight is not a consideration, why then should the shape be a consideration. If it's shape is related to it's length then i'll simply over or under-seat based on the specified COL within parameters of being safe and firing accurately. If it's a shorter bullet than my last one then I'll seat it shallower to reach the same COL that I had with the previous bullet. Whether it's closer to min. or max. COL is a different discussion. I'm simply trying to determine the correct steps and necessary components and measurements among (not inaccurate) different answers.
??? |
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#28
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Allan. I'm more concerned with the process then the activity at the moment. And yes, Made some 125 grain RN cartridges. Can do a plunk test on Tues. when gun is back from PRP. I can't exactly shoot in my backyard, so going to the range with only one cartridge to "try out" isn't all that efficient. Respectfully.
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#29
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Quote:
Bullet weight is important. So is bullet shape. Weight determines the baseline powder charge. Simple physics: it takes X amount of energy (powder charge) to overcome the inertia of the projectile and accelerate it to a given velocity (bullet weight). Bullet shape can increase or lessen the amount of resistance of that projectile in the barrel, which involves the pressure generated by the powder burning. Caliber also plays a part, because the bigger the bore is determines what bullet shapes work best. 9mm/.357 bore means bullets will be, of necessity, longer as weight increases. Longer means more bearing surface, which affects pressure. If you move the weight forward toward the nose of the bullet (round nose), you reduce the bearing surface somewhat due to the taper of the ogive. A cone shape puts the weight more toward the rear, increasing bearing surface. That can increase bullet seating depth as well, as increase pressure for a given weight. In large bores like .44/.45, light weight bullets tend to have very short bearing surfaces, so you see a lot of truncated cone and SWC shapes. If you increase weight and want to avoid having to seat too deep, that weight goes into the nose, and you tend to get heavy round nose and wide SWC profiles. All this stuff is affected as well by COL (think in terms of cylinder length in a revolver, or what fits in a magazine in an auto-loader). Increase bullet weight within a length restriction context, and by necessity you have to seat the bullet deeper. That increases pressure, and max pressure limits how much powder you use for that weight. Point being, all of this is interrelated. There are no simple answers. You have to learn the terminology, and how changing one variable - say bullet shape - can affect the other parts of the equation. You got good advice when somebody said to start with one bullet and one powder. When you know what that combo does when you change seating depth up or down, or change the charge, then you're ready to start changing bullets, or trying different powders. What you seem to be doing at this point is trying to oversimplify things too much. That is going to do nothing but frustrate you. Take your time. We've all been through this, and it does get easier as you learn.
__________________
Vietnam Combat Vet - U.S. Navy 1970-1974 NRA Benefactor Life Member Extremism in the defense of liberty is no vice - Barry Goldwater When Injustice becomes Law, Resistance becomes Duty - Thomas Jefferson |
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#30
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Wow, ignore my last post. I was half awake when posting that and have no idea why I ignored bullet weight.. Especially since it's the first thing considered when prepping your press for a cartridge. Sorry, sometimes I surprise even myself with stupidity.
EDIT: Anyway, what I DIDNT screw up was my thoughts on bullet shape and it's consideration in throwing a load (that didn't sound right). |
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#31
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BTW, in reference to a lot of our conversation.. This was taken from the "Basic Reloading" Sticky posted by cfi542
look up the cartridge you're working on and consult the tables until you find the one for the weight bullet you're using. the bullet they describe may not be identical to what you're using, but the only really important thing is that the weight is the same. |
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#32
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while there can be bullet TYPE (lead, plated, jacketed) substitutions, this is something a newbie needs to be careful about and not make decisions without expert consultation. there are differences between same weight bullet types that can affect the safe cartridge load paradigm.
__________________
NRA Life Member ~ MOLON LABE - Leonidas, 480 BC |
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#33
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Can you give me an example? You know the different types of bullets I'll be using from past conversation. Do any of them apply to possibly being unsafe if not loading according to recipes based on the bullet style/s also?
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#34
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Refering to data for non identical bullets, I would not agree that the "only" thing to be concerned about is weight. Weight is the most important thing. But the seating depth can have a major effect on pressure. Not the COL, but the position of the base of the bullet. That determines the volume that the powder occupies in the case. Bullets of the same weight but different shapes will probably be a different length. So even if seated to the same COL the base of the bullet will be seated to a different depth in the case. Changes in seating depth will have a major effect on pressure.
__________________
Don't believe anything you hear and only half of what you see. USPSA A-27738 Allan Last edited by Alland; 04-30-2012 at 08:46 AM. Reason: sp |
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#35
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No doubt Allan, but there's no mention of measuring my bullet seat depth anywhere in the few hundred pages of my Lee Handbook. I'm basically going by the COL min and max numbers and veering toward the max COL to play on the safe side.
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#36
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So I just got off the phone with a tech from Hogdon about the lack of load data for my two bullets that I couldn't locate anything for regarding my AutoComp Powder.
He started by saying that if I couldn't find a recipe for my AutoComp Powder with the Lead bullet i'm using then simply substitute it for load data regarding the same weight bullet but "Jacketed" (start with starting load, increase 1/10th at a time), this is concerning any and all load data I need in which there's a recipe for a jacketed version but not a lead version. He pointed this out in the instance of my RNFP 147 Grain Lead Bullet, saying that I should use the same weight jacketed bullet in the E-Mail he sent me. Well the only bullet that weighed 147 grains in that E-Mail was jacketed, but was specifically a Hornady XTP bullet. My 2nd problem child is a 120 grain Lead TC bullet which I found nothing for. He said to use the recipe for the Lead Conical Nose bullet, working my way up from the starting load data. Keep in mind, this was a tech reached through the automated board of the Hogdon website which directed me via the choice of..for all handloading data press 1. Which is how I was connected to him, so he obviously knows what he's doing. |
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#37
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My point is that relying on COL when changing to a different bullet style can create a dangerous situation. The COL listed in a manual applies to the specific bullet used to obtain that data.
__________________
Don't believe anything you hear and only half of what you see. USPSA A-27738 Allan |
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#38
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I just measured 3 different bullets. One copper coated RN, one LRN and one LSWC. non of them deviating more than 3/100's from one another. I fail to see the danger in this instance..?
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#39
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all this talk is why it's really important for a newbie to first find lots of well proven load data and then select components based on availability.
using autocomp powder will limit your 9mm loads. after i looked through the hodgdon's autocomp online 9mm load data, and through all my plethora of acquired load manuals for 9mm and all powders, autocomp is not a good choice. why? 1) because there isn't much autocomp load data available 2) the safe load range for autocomp and 9mm is but .5 grains 3) always best to use powder with a wide start/max range 9mm and w231 has as much as 1 full grain of leeway from start to max. yer gonna hafta scale that autocomp carefully.
__________________
NRA Life Member ~ MOLON LABE - Leonidas, 480 BC |
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#40
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Doesn't do me any good now. I'm not about to throw away almost 30 bucks worth of powder.. nor am I gonna save it for a rainy day, so to speak. ;-)
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#41
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If the tech at Hogdon's said it, I trust it. Once I have that starting point, i'm not gonna blow any appendages off modifying by 1/10th grain at a time. I'm not worried.
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#42
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Quote:
the deeper you seat a bullet, and have a shorter oal, the more pressure is generated as the round goes "bang!". so in reality, the oal hasta do more with chambering, feeding - though how DEEP any bullet gets seated compromises case volume, and there can be pressure issues. when you look at qualified load data, the oal given is for that particular bullet in the recipe. if you seat that SPECIFIC bullet to achieve the listed oal, resulting pressures should be fine. seat that same bullet LESS deep and it will be fine as long as the round passes the plunk test. seat that same bullet DEEPER and no question there will be increased pressure during firing.
__________________
NRA Life Member ~ MOLON LABE - Leonidas, 480 BC |
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#43
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A seating depth increase of .030" in a 9mm will produce a MAJOR increase in pressure.
__________________
Don't believe anything you hear and only half of what you see. USPSA A-27738 Allan Last edited by Alland; 04-30-2012 at 09:23 AM. Reason: sp |
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#44
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that's why i said "yer gonna hafta scale that autocomp carefully."
__________________
NRA Life Member ~ MOLON LABE - Leonidas, 480 BC |
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#45
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Quote:
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#46
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No worries. I would no matter how fast burning it were or how small the min to max safety scale was anyway.
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#47
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Point taken, but to be fair that was the one copper jacketed bullet and the other two were lead so I understand the danger possiblities there. My mistake.
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#48
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BUT, on the other hand. What is .03 really going to cause if the bullet is seated that much deeper? I'm still not up on any of the algorythms to calculate pressures.. but I'd like to know what kind of pressure increase that is going to cause approximately, for a 9mm `120 grain LRN bullet and cartridge..?
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#49
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Quote:
or, restated, P2 = P1 x V1/V2 (the pressure is proportional to the ratio of the volumes) That's the theory. In practice, it's almost impossible for a hobbyist to get a meaningful answer. First, you'd have to know exactly which bullet you're dealing with, and it would have to be a bullet well dimensioned in the manual, so that you'd know EXACTLY how far into the case the base of the bullet was seated to yield the pressure shown in the manual. If you can reliably establish that, then re-calculate the reduced case volume with the bullet seated deeper (i.e. .003" in the example above). With this new (smaller) case volume, use the volumetric ratio shown above to calculate the reduced case volume internal pressure.
__________________
NRA Life Member |
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#50
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That actually sounds familiar to one of the calculations from the Handbook. Yeah here it is.. You have to reduce the powder one grain at a time then multiply the press. factor to get the equivalent PSI reduction for one simple grain reduced. Not exactly a simple process.
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