Probability and Statistics, Work up sample size
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Coincidentally today I sat down in the barber’s chair today and a college kid was talking about his probability test he has to take for, I think, being an actuary. I wanted to ask him about picking out colored marbles in a bag but I kept my mouth shut so I wouldn’t cause the barber to mess up my beard.
get an old wool army blanket, fold it up so you have two, or three, inches of padding and drape it over your shoulder. this works wonders when you are pounding twenty rounds down range working up a load.
how accurate is that commercial load you were shooting? use that as a baseline for your load workup accuracy.
luck,
murf
Varminterror
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Very comfortable.
The load development method I currently use tends to take 40 rounds, and includes triplicate execution of the test. 10 foulers, 10x3 development shots. Done. This gets me within the realm of where I need to be for everything I need to be with a rifle.
The premise you’re describing is false - Max load data is not on the razor edge of the mechanical integrity limit of the firearm. So running a little over max even, will not yield catastrophic failure.
BWS
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What's the chamber's neck I.D.? What's the leade look like?
There are reasons folks "break in" barrels that aren't,or may not be so obvious. The first thing I do on any new rig that comes across the bench here gets the chamber mic'd,and noted(I prefer direct measure vs chamber cast,but that's me).Then there's a few other measures and considerations that get recorded. Once the fire forming begins,you "should"(comes with experience) be getting an idea of how the rig/cases are going to take to the whole process. Skipping these early stages,INCREASES the need for caution and care WRT "working up a load".
Chrono some factory ammo,get more serious with your metrology,and really try to define what your goals are. Good luck with your project.
There are reasons folks "break in" barrels that aren't,or may not be so obvious. The first thing I do on any new rig that comes across the bench here gets the chamber mic'd,and noted(I prefer direct measure vs chamber cast,but that's me).Then there's a few other measures and considerations that get recorded. Once the fire forming begins,you "should"(comes with experience) be getting an idea of how the rig/cases are going to take to the whole process. Skipping these early stages,INCREASES the need for caution and care WRT "working up a load".
Chrono some factory ammo,get more serious with your metrology,and really try to define what your goals are. Good luck with your project.
GeoDudeFlorida
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He’s talking about using 16, total.
Seedy Character
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Use your 150gr data, load the 139 and see what you get.
My 7mag loved 139gr bullets. At close to published MAX.
Sometimes you have to work with you can get.
May have to limit hunting to 300 or less. But you have ammo and are hunting.
My 7mag loved 139gr bullets. At close to published MAX.
Sometimes you have to work with you can get.
May have to limit hunting to 300 or less. But you have ammo and are hunting.
Correction - Was talking or was asking. Past tense
.Mainly was asking opinions before doing. No longer doing. I’ll work up the load, get what I get, and cross my fingers more components come into my possession before this time next year to test things out at distance.
I kind of realize my question wasn’t the best. The manuals that give max load are the same manuals that tell you how to work up a load and be cautious. So cherry picking one part of the manual and disregarding another is, maybe, just possibly, contradicting.
A general rule of thumb if mine, of which I still have both, is, “If you ask a question for confirmation, you probably know the answer.”
A general rule of thumb if mine, of which I still have both, is, “If you ask a question for confirmation, you probably know the answer.”
GeoDudeFlorida
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Every time.
It's kind of the shooting equivalent of, "Hey y'all, watch this! (hold m' beer)"
lordpaxman
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I start low and work up. I was running an OCW on .243 with IMR 4955, first time using the powder and using Hodgdon data and the just below minimum charge had V way over what the maximum charge predicted. Even in these lean times, I would not start near maximum with unknown variables. OTOH, I have reduced N significantly until I get near my desired goal. Good luck.
One thought I was having as well, instead of thinking of load development and ballistic testing as two separate events, combining them would save redoing them. Documenting point of impact relative to what I’ve dialed for windage and elevation along with atmospherics as I shoot. In other words, don’t think of work up loads and groups as “wasted” ammo. I think I was trying to “resolve” that in my mind and looking for affirmation.
GeoDudeFlorida
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No, not a kaboom (thank goodness!) and not with a rifle cartridge but, I did blow the head off a HBWC in a No.2 .38 caliber Enfield revolver using a published max load and published OAL. Stuck half the bullet in the forcing cone and the other half hit the target, made a nice round hole low and left. If I hadn't been paying attention I'd have shot again and possibly created a bad situation but still "probably" not a kaboom given the strength of those old No.2 Mk.II Enfield revolvers. It turns out the Speer swaged 148gr. HBWC's are not as thick at the neck as the cast HBWC the author was using. Lesson learned: just because you have "the same bullet" as was tested that don't mean you have the same bullet as was tested.
AJC1
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I'm going to assume that you are required to use lead free bullets in your area, and your chasing velocity because your using a mono and speed is required to get the required expansion.....
If the above is not true get a box of any other bonded bullet and do a good workup. Having a secondary load as a backup is something worth doing all on own.
Buy one box of factory use 10 to sight in and 10 to hunt
Or do a minimal workup and limit your range as to reduce possible injury of animal.
You have options and forcing a bad reloading plan is not a good one.
If the above is not true get a box of any other bonded bullet and do a good workup. Having a secondary load as a backup is something worth doing all on own.
Buy one box of factory use 10 to sight in and 10 to hunt
Or do a minimal workup and limit your range as to reduce possible injury of animal.
You have options and forcing a bad reloading plan is not a good one.
Charlie98
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Although it sounds like you have it already figured out, I'll offer this...
Reducing 1grn from a theoretical 69grn max load is only a 1.4% reduction; reducing 1grn from a theoretical 25grn load is 4%. I would rather reduce 4% and work up vs an almost statistically irrelevant 1.4%... and I say 'irrelevant' because there are simple variations in powders, charge weight, bullet lots, brass lots, etc, that can add up to that... and more.
LiveLife
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Then you might not get the optimal accuracy load for YOUR rifle this year either.
In addition to RELOADING VARIABLES like powder charge, bullet OAL/seating depth, distance to lands, neck tension, etc., there are also SHOOTING VARIABLES specific to your rifle such as barrel harmonics/timing so to identify an optimal accuracy load for your rifle/barrel, at the minimum, you would first need to work up powder charges for a given OAL/distance to lands (And then perhaps incrementally reduce OAL to see if group size decreases). Can this be done with 16 rounds, especially verified at 200/300/400/450 yards? (Of course given other shooting variables such as shooter using same precise exact trigger pull and cheek weld/hold not to mention wind condition being the same for every shot)
I don't think so.
I would agree on sample size.
And consider that many often find TWO ACCURACY NODES so simply starting with 1 grain reduction and working up to max charge may not identify the first accuracy node.
Has anyone experienced a serious issue (Losing control to crash) driving a car at published TOP SPEED? Well, there are road condition and driving variables ... Even when they are careful about driving ...
If you want to minimize the number of rounds it takes to identify an accurate load for your rifle/barrel, you may get a head start by asking what others have done using the same rifle, bullet, powder and headstamp brass. Heck, you may even get lucky when a member posts, "I have the same rifle and X powder charge with Y bullet and Z OAL consistently produced smallest groups" and the same load may just work for your rifle/barrel too.
Here's an example. If one was developing an accurate load to shoot at 1000 yards, referencing other shooters' "pet match loads" may help developing your load, particularly if using same rifle/barrel - https://web.archive.org/web/2015031.../01/reloading-western-shooters-pet-loads.html
FYI, here's advanced rifle reloading thread you may want to check out to optimize accuracy for your rifle - https://www.thehighroad.org/index.p...s-and-discussions.778221/page-2#post-10938613
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Agree 100%Buy commercial ammo this season and handload when you have the supplies to do it right.
How can any of your questions be answered? We don't even know which cartridge, chambering, caliber, action, barrel, bullet or powder you're talking about. X+1 vs. X-1 grains of A-type powder in a Y-type cartridge case with Z -type projectile of R diameter loaded into D-type action... Say what?
Start at the beginning. Don't take shortcuts. Do it right according to what works. That's how you avoid ending up with a new nickname like "Stumpy" or "Ol' One Eye."
Has anyone experienced a serious issue (Losing control to crash) driving a car at published TOP SPEED? Well, there are road condition and driving variables ... Even when they are careful about driving ...
Well, I'll admit it, I usually drive 5 over. Faster if that is what traffic is doing. And I pass people going slower than the speed limit. I'll also admit my worst accident happened doing the speed limit - when good conditions changed to bad conditions real quick (black ice). There are some analogies to made here.
Not to make too many analogies here, but...
But I digress.
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