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Old December 13, 2012, 08:29 PM   #1
leadchucker
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Loading to factory specs

I'm fairly new to reloading, and I try very hard to follow the accepted practice of using the starting load data and working my way up to a load of acceptable performance, for a particular bullet type and weight, powder, primer combination. Haven't created any monsters yet.

I can see how variables could adversely affect a load's performance and safety.

But let's say you get the same brass, bullets, powder, and primers as a factory round, and you load rounds to the identical specs of the factory round. You've eliminated all the variables. You should be able to expect the rounds to perform identically to factory ammo, without the usual routine of working up to that load.

Can that be done, practically? If not, why not?
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Old December 13, 2012, 08:53 PM   #2
Brian Pfleuger
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You didn't eliminate all the variables.

Your gun doesn't have their chamber or barrel and you almost certainly don't have the same Lot #s of primers and powder.
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Old December 13, 2012, 08:57 PM   #3
GeauxTide
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Load to reloading manual specs with better than factory bullets. Happiness will ensue.
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Old December 13, 2012, 09:14 PM   #4
Rusty35
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Brian Pfleuger
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You didn't eliminate all the variables.

Your gun doesn't have their chamber or barrel and you almost certainly don't have the same Lot #s of primers and powder.
Factory ammo has been tested in my guns
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Old December 13, 2012, 09:25 PM   #5
leadchucker
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Ammo makers routinely turn out ammo that fires safely in the vast overwhelming majority of guns out there. It wasn't worked up in your gun, like your handloads are, and yet it is predictably safe in your gun.

What have the ammo makers got that we don't have? Why can't we replicate the predictability that the ammo makers can?
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Old December 13, 2012, 09:26 PM   #6
reynolds357
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The only way I really know you could duplicate a factory load would be the Hornaday factory loads that have the recipe on the back of the box. I can look at powder and make an educated guess as to what it is, but I can not tell you with any degree of certainty what a powder is by looking at it. Many of the powders the factories use are not even available to reloaders. I remember reading many years ago that Winchester goofed up a huge lot of powder they could not sell to the reloading market so they factory loaded with it.
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Old December 14, 2012, 02:30 PM   #7
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But let's say you get the same brass, bullets, powder, and primers as a factory round, and you load rounds to the identical specs of the factory round. You've eliminated all the variables. You should be able to expect the rounds to perform identically to factory ammo, without the usual routine of working up to that load.
Each lot of gunpowder is different. Powder suppliers, such as Accurate, IMR, blend lots of fast and slow powder so the last lot of, lets say AA2495, is close to the last lot you bought. Accurate Arms told me that they blend their lots to 5% but that the industry standard is 10%. So different lots of powder are going to have different pressure curves.

We get blended powders. Ammunition manufacturer's use the unblended stuff. It is cheaper and they have the equipment to measure the pressure curve.

I have done some searching on the pressure variances due to primers. There is data out there and it is surprising to see numbers like 7000 psia and 4000 psia max and min's for primers. Given that primer cake is mixed by hand, and the ingredients in vary, because everything varies, the next batch of primers you use will be different from the last.

Of course brass varies in weight.

There are a lot of varibles in ammunition.
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Old December 14, 2012, 02:40 PM   #8
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What have the ammo makers got that we don't have? Why can't we replicate the predictability that the ammo makers can?
In short: pressure testing equipment.

The factories take whatever powder and primers they have and use their pressure testing equipment to find a load that comes in under the SAAMI pressure limit when used in a tight-spec'ed SAAMI test barrel. Those barrels are designed such that they will produce pressures equal to or higher than the highest pressures that barrels sold to comsumers will produce.

You could produce exactly the same ammo ONLY IF you had EXACTLY the same powder and primers (same lot numbers, not just same names) as well as the same lot of cases and bullets.

But, you don't. That is why we need to work-up our loads. If the stack-up of differences between what we have and what the loading manuals tested goes towards high pressure on every component, then it is entirely possible to exceed SAAMI pressure limits with our handloads. There is some safety margin between the SAAMI limits and the pressure that will burst a gun. But, exceeding the SAAMI limits routinely will wear a gun much faster, and leave less than necessary margins for other factors, like high ambient temperatures, dirty bores, etc.

There are some signs of excess pressure, but those depend on what pressure is the limit for a particular cartridge. For a high pressure rife cartridge (e.g., a .270 Winchester) in a strong bolt-action rifle, there are plenty of warning signs that the pressures are higher than the SAAMI limit. But, for low pressure revolver cartridges (e.g., a .45 Colt) in a weak revolver design, there will be NO RELIABLE pressure signs until you are way over SAAMI pressures specs.

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Old December 14, 2012, 07:30 PM   #9
oneoldsap
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Why try to duplicate factory loads , when you can make better ammo !
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Old December 14, 2012, 09:12 PM   #10
reynolds357
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I would have agreed with you some years ago that handloads are better than factory loads. Having said that, I have not yet been able to beat what Norma turns out for Weatherby. Norma is on top of their game. So far, they are on top of my game as well.
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Old December 15, 2012, 08:01 AM   #11
oneoldsap
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You aren't considering the cost factor ! I can construct 60 rounds for less than the price of 1 20 round box of Norma ammo . It's fine for the guy that a box of ammo will last three or four years . For the avid shooter , not so much !
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Old December 15, 2012, 09:30 AM   #12
SL1
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I agree that reloading economics needs to be discussed in the context of the COMBINATION of economy and accuracy.

I can load ammo that costs half (or a little more) of what the cheapest ammo costs, but that does not include the costs of all the tools that I have acquired to do that reloading. But, that economical handloaded ammo certainly shoots much better than the cheapest factory ammo.

On the other hand, it is hard for me to load ammo that is more accurate than the very best factory loads. Sometimes I find the "magic" combination for a particular gun that outshoots everything else, and sometimes I don't (yet?). But, the ammo that I reload that is about the same quality as the best factory ammo is MUCH cheaper than that factory ammo.

So, it really comes down to how much GOOD ammo do you want to shoot? If the answer is "not much," then perhaps buying all those nifty handloading tools is not for you.

On the other hand, if you want to shoot enough to get really good with your gun, then handloading seems like a good idea, because it can provide a lot of good ammo for a reasonable price.

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Old December 15, 2012, 01:04 PM   #13
RC20
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I fall on the side you will be fine.

That does ASSSUME tht you indeed id the same powder.

Factory loads to the lowest common denominator (old guns if they exist).

When a gun will take a 150% proof load and no issues then it takes an extraordinary screw up to push one over the edge (grease the bullet or leave grease in the barrel per the 1903 low serial controversy)

And you can do the same thing with any load (screw up)

So yes, if you can truly ID the powder then not an issue.

You will find they are below the max also (test it with a chrono and see!)

I have yet to see one meet the advertised.

The nonsense about the same gun is just that. That data in the re-load d manuals is there to ensure you know what your plus or minus performance is.

Obviously you are almost certainly going to shoot it in a different gun with a different barrel length and a different chamber, in factory or re-loads, sheese.

It is not there to ensure you have to shoot that same gun or risk death ir dismemberment
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Old December 15, 2012, 01:14 PM   #14
buck460XVR
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I fall on the side you will be fine.

That does ASSSUME tht you indeed id the same powder.
Same here. Since ammo manufactures may use blends and proprietary powders unavailable to the handloader, this is not always doable. Ammo manufacturers generally do not give out their recipes either. About all one can do is to get the same projectiles and a chronograph. Then shoot the factory ammo outta their firearm to determine the velocity outta their gun....not the velocity stated on the box. Then one can load that similar projectile to the same velocity as the factory ammo.........if the published load recipes show you are not above max for the powder being used. Most of the time one can easily match factory velocities. But since there are many variables, such as crimp and how the case was re-sized, even getting the same velocity as factory ammo does not mean your ammo will be more/less or as accurate as factory.
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