How do you "work up" to a max load?


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Rustynuts
December 31, 2007, 05:59 PM
I see everyone say to start out 10% lower than recommended and work your way up to a maxed out load (if that's what you want). I also read somewhere that even using a chrono doesn't really tell you everything that's going on inside the round, pressure wise. So how do you REALLY know where you lie safety-wise with the round as you work up to hotter loads?

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scrat
December 31, 2007, 06:39 PM
its not always about how much powder you can put in a round till its almost ready to make your gun explode.

When reading a chart for load data that says max load. This is what someone has worked up to. sometimes you have to check different sources as 4 different books will tell you 4 different things. You see what they do is take test rifles and work up loads in those rifles with different bullets and powder and record the results. Depending on who wrote the information. They could have stopped at what they felt was the maximum safe working pressure or they could have stopped once they achieved what they wanted. Here is what your job to do is.


ok lets say someone shot 150 grn hornadady fmj (full metal jacket). out of a 30-30 bolt action using 30 grains of H4895 and win large rifle primers. They achieved 2300fps. What you dont know is how good the load was. So your going to shoot the same thing. You take it down to 26 grains. load up around 10 bullets, load up another with 27 then 10 more with 28. Now go to the range use sand bags a rest or something. Just make sure your rifle is securely mounted then aim right at the center at 100 yards. fire 3 shots. look through a spotting scope. change the target or shoot at another area or something. What your trying to do is find out which load works better to give you the best accuracy. You may never get to 30 grains. AS at some point there is going to be a curve where performance and max powder have been achieved. Using any more powder will start to give you negative results. Thats your guns Max load rate for that bullet, powder, primer, col(cartridge overall length). Write everything down. most people wil make up a sheet in excell or something.

scrat
December 31, 2007, 06:44 PM
ok part 2


why we do this.
different guns will give you different effects. Your gun will not always be the same as the test gun in a load data report. Thats why you can look at different load data reports and get different things. So what a lot of us do is buy different powders and different bullets and find out what works good with each powder and with each bullet. then you will be tailoring the bullet and load to the gun. Then later on if you run low on bullets and your about to buy some or order some. You can look in your closet or where ever you keep your powder and see what you have on shelf. Then you can look at your own load sheets and see what bullets gave you the best performance for that powder and you will know what to get.

Say your going hunting. Your planning on deer at maybe something within 200 yards. ok check your load data sheets. what gave you the best accuracy for this type of range.

USSR
December 31, 2007, 06:57 PM
I see everyone say to start out 10% lower than recommended and work your way up to a maxed out load (if that's what you want). I also read somewhere that even using a chrono doesn't really tell you everything that's going on inside the round, pressure wise. So how do you REALLY know where you lie safety-wise with the round as you work up to hotter loads?

Rustynuts,

While a chronograph alone may not tell you everything about pressure, use of a chronograph with a powder suitable for the cartridge/bullet weight combo, the knowledge of what you can expect velocity-wise with this combo for the rifle you have, along with the ability to read pressure signs on your brass, is the best way to approach load development. While you will never get in trouble using starting loads in published manuals, you will also never get optimal performance out of your rifle, even when using their published maximum loads. The reason is, the so-called maximum loads in these manuals are loads that are vetted by the publisher's lawyers, as opposed to actual maximum loads, which vary from one rifle to the next. By using the above combination of methods, you can safely reach the maximum performance level that your particular rifle will support. Hope that helps.

Don

HankB
December 31, 2007, 07:10 PM
The best teacher is experience and the experience of others . . . especially those who write loading manuals for component manufacturers.

I note that "maximum" charges listed in loading manuals vary from manufacturer to manufacturer, and often vary (greatly!) from one edition to another from the same manufacturer.

In some cases (e.g., modern bolt action rifles shooting modern cartridges) gradually increasing the powder charge while carefully keeping an eye out for signs of excess pressure - stopping when you see them - will avert disaster.

On the other hand, in some low-pressure cartridges (.32 ACP, 12 gage shotshell) you can be well into the red zone before you see any of the traditional pressure signs.

And of course, some old cartridges (7mm Mauser, .45-70) which were originally low-pressure numbers can be safely loaded WELL beyond original specs in SOME modern firearms.

Most major reloading manuals devote a chapter or two to reading pressure signs - I suggest you read these and then apply basic common sense to your reloading.

Steve C
December 31, 2007, 07:11 PM
There are 2 main reasons you work up a load.

The first is pressure of the round. The maximum load listed in a manual is either the point where pressures become erratic or the pressure comes close to the maximum allowable by industry standard. Differences in the loads produce differing results and some may produce higher than allowable pressure. Different lots of powder and different primers, bullets, brass and firearms produce different levels of pressure. The 10% reduction from maximum is considered safe enough so the variations between components are unlikely to give you a load with excessive pressure. The hand loader should assemble loads using a set list of components with samples of powder charges ranging from the 10% reduction to no greater than the maximum load. These loads can then be tested starting from the lowest charge to see if signs of excessive pressure are observed. If pressure signs appear then fall back at least the previous lower charge weight.

The second reason you work up a load is to obtain the best accuracy out of your particular gun. The most accurate load is most often not the maximum load but somewhere below that. So in addition to testing the loads for pressure one should test for accuracy. This is especially evident with rifles where a 1/2 grain difference can change group size by inches at a 100 yds. More important for target shooting (maybe) but its nice to know you can put the round exactly where you aim.

Bitswap
December 31, 2007, 07:32 PM
I'll chime in on this.

You may read four books and get four different maximum loads for your powder / bullet combination. You need to test these to and look for pressure signs to determine the maximum.

Maximum loads are used by hunters. Drop a grain from your maximum pressure loads and see how they group, if acceptable then keep it.

The maximum may not be the most accurate. There's a little thing called barrel harmonics that comes into play. I can usually find two harmonics for a particular gun. This will be your optimum FPS for that barrel. Once you find this, you're looking at hitting targets out to 400 yards... or more.

I'm in the camp where I'll give up some energy for accuracy. But it's a real pain in the arse to find it. I personally don't care about the maximum load and don't test for it. I do check for over-pressure signs though.

Pressure per grain is not a linear function, it is exponential, so be careful.

jfh
December 31, 2007, 08:04 PM
I think what you are asking for is "what 'signs' can be used to determine whether or not increases in a powder charge is a MAX load?"

IOW, you are trying to understand "the deltas"--that is, the change in components or ballistic data that occurs when we vary one of the elements of the recipe.

There's the "hard data" side of this: This includes measuring brass--for example the change in LOA of the case, the change in diameter at a point 1/8" from the base, and so on. It also includes chrono reports, including velocity changes, and the statistical evidence (EDs, SDs) of how 'repeatable' the occurance is. We assume, IOW, that small variations make for a "better" reload recipe. And, we use accuracy as part of our assumption that we've built a "better" cartridge.

The "soft data" includes those subjective evaluations, such as "the recoil is harder," or "that recoil was much harder," or "Wow, that was much louder, that sort of thing.

Much has been made of "reading primers"--looking at them to see how they've changed, both from the UNfired condition and from the "deltas" of the recipe changes.

Like strat said, lots of people record these changes in spreadsheets.

Arguably, the use of ballistics software can help one understand the pressures a load theoretically develops. I plan to learn and start using QuickLOAD this winter.

For now, however, I am going to do "some" brass measurement and analyze (chrono) velocity changes. My testing last summer did approach an overpressure load with one powder in a 38 Special cartridge--the velocity did NOT go up as expected, the ES opened up, and the accuracy dropped. But, after my overpressure incident in June, I am reasonably convinced that reading primers is about as reliable as looking at your palm lifeline or reading goat guts you harvested at midnight on a moonless night.

The quick answer: drop that 10% from a published / recommended maximum, work your way back up, but stop when the round is accurate--and don't go over the published load.

Jim H.

Walkalong
December 31, 2007, 08:18 PM
The quick answer: drop that 10% from a published / recommended maximum, work your way back up, but stop when the round is accurate--and don't go over the published load.

Jim H.
There you go.

scrat
December 31, 2007, 08:47 PM
#9
Walkalong
Senior Member



Join Date: 11-20-06
Location: Mont. Al.
Posts: 4,222 Quote:
The quick answer: drop that 10% from a published / recommended maximum, work your way back up, but stop when the round is accurate--and don't go over the published load.

Jim H.

There you go.
hahahah much better said

scrat
December 31, 2007, 08:48 PM
or get the load from 4 books. add them up and divide by 4

smitty_bs
December 31, 2007, 09:28 PM
I actually keep all shooting magazine articles that show handloading data for my cartridge. I also have several manuals and loadbooks as well as Ken Water's "Pet Loads" book as well as his updates.

Last year I compiled the data from all these various sources into excel spreadsheets for each bullet weight and powder I was interested in. The data spans about 40 years. The excel spreadsheets show the starting loads, mid loads and max loads and the corresponding velocities.

It is surprising that with all these data sources that most of the max loads are pretty darn close to one another - that is they don't seem to vary my more than 2 grains for 30/06 size cases. There is an occasional anomaly, but overall the variation is not as great as I thought it would be for the powder charges. The velocities however do vary quite a bit.

Get whatever data you can get your hands on, average it and drop it 5 - 10% and you should be fine. Them's my 2 cents.

snuffy
January 1, 2008, 12:29 AM
Get whatever data you can get your hands on, average it and drop it 5 - 10% and you should be fine. Them's my 2 cents.

Caution, the above statement should read drop the maximum by 5-10%. Do not drop the recommended starting load by 10%. In most cases that wouldn't cause problems, but with the very slow powders used in the big magnums, reducing below recommended starting loads can be dangerous. Most loading manuals already have the max reduced by 10%.

There's two reasons to "work up" loads. One is to get as high a velocity you can safely get, the other is to strive for that holy grail of reloading, the 5 shot one hole group. Then to be able to duplicate it. Once in a blue moon you get both!

When I'm striving for accuracy, I generally start in the middle. Between the rec. starting load and max. I'm not interested in an accuracy node at or slightly above the rec. starting load. It's a waste of components to shoot those lower loads. If the gun is new, I may load one shell each at the lower loads. I most always am using my chrono when doing load work-ups. So I can see what the velocity is for the lower charges, just to be safe.

Sport45
January 1, 2008, 12:46 AM
I agree with scrat and Jim H. work the load until it's accurate and stop there. The only part of scrat's procedure that I would change is the 3-shot group. I believe you need at least 5 and maybe as many as 10 shots to really show how the rifle shoots.

But if you're a hunter the only one that really counts is the first round out of a cold non-fouled barrel. Group size doesn't matter much as long as you know where the first shot is going. I knew a guy in East Texas that often "sighted in" his hunting rifle with one shot. If it hit within an inch of where he was aiming at 100 yards he put it back in the case and called it good.

Rustynuts
January 1, 2008, 09:14 AM
Thanks all, very informative! As you can tell, I just started and have my first reloading book on order. I'm sure a lot of these newbie questions will be answered there, but I still like other voices of experience!

Walkalong
January 1, 2008, 09:55 AM
??????? Guess I'm just slow.

jfh
January 1, 2008, 10:31 AM
"??????? Guess I'm just slow."

That must be the problem, Walkalong. Or, at least I am slowing down.

Jim H.

jfh
January 1, 2008, 04:03 PM
I think we can expand some more here on working to max loads and the 'reasons' we reload.

I come from a marksmanship background--so when I started reloading (initially for 1911s--first .45ACP, then 10mm), I sought out accurate loads. I quickly learned about 'softball' loads providing the most accuracy (in 1980s frames), and I learned to tweak those to meet other goals--like Major PF, that sort of thing. I even learned to do some full-bore 10 mm handloads, and I discovered they were the most accurate rounds from my 1006.

But, overall, I sought an end goal of a accurate, economical round--typically 231 behind a 200 gr LSWC, and as low as 4.9 gr--and that's for both calibers, BTW, but that's another story.

This year I had a new goal in mind: this was the development of a 'replica' round for PD practice. We all know you need to shoot a lot to 'get good.'--but good in the use of a j-frame carried for PD does involve a different set of parameters, I think. Essentially, I wanted to shoot a round that was 1) as near as possible to feeling like the factory round I elected to carry, and 2) provide me with the cost savings that would allow that practice. Along the way, if that reload ended up shooting to the same POA, or even at the same general ballistics, fine--but it had to "feel" as much as possible like the factory round.

So, what does this have to do with MAX loading? Well, first of all, some of us know that 'duplicating' factory ammo velocities can be difficult to do with the powders we can buy for reloading. Related to that, of course, is the issue of safety via overpressure, etc., etc. Specifically, that meant working in the +P and even +P+ range of the 38 Special cartridge (at least by current SAAMI specs), as I mentioned earlier.

Again, I found it interesting that the most accurate roads (in my two 2" j-frames, an M&P340 and a 640) with the powder that produced the most-similar subjective recoil, was at or near MAX. Since I shot these rounds from a 357-sized J-frame, the actual shooting safety was not influenced--but I sure wouldn't run a lot of them through the 40 year-old 36 I've got as well.

And--until several hundred rounds has been fired--I didn't break out the chronograph: I relied on studying the subjective recoil and then letting that quide my next development. However, all of the testing remained at or below the published MAX data.

Then I 'translated' those loads--which were now ballistically defined as a .357 -dia. 140-gr lead bullet running at about 880-910 fps--into 357 cases. That makes an entirely safe round; I doubt any of the reloading versions run over 23,000. It also means I can shoot for about 10 cents a round instead of the 55-cents to 1.00 per round cost of the factory ammo.

And, it means that for training ammo (for example to help someone else learn to shoot j-frames), loads can be reduced as needed to deal with recoil.

It even turns out that the various reload recipes, in both calibers and with five different powders so far, shoot to very-slightly different points of aim at combat distances--e.g., out to 15 yards--and can group as well as the factory ammo.

So, when you start a reloading project--my "replica loads" project has continued to expand--try writing out an explicit statement that incorporates your need, as well stating the normal implicit ones of accuracy or velocity.

Jim H.

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