Reloading at or above Maximum?

[Bowhunter57]

I have 2 good friends that have told me this method for finding the best reload, both of which have more experience than the average person. The "theory" is based on most rifle's efficiency or performance curve.

This is how it was explained to me:
According the online IMR reloading data, it shows (for a 22-250) 36.3 gr. of powder will give 3713 f.p.s. Knowing that both of my friends would load a 55gr. bullet with 37.0 gr. of powder, shoot it and check the primer to see if it had flattened out. If not, they'd load 38.0 gr. of powder, check it and it if wasn't flattened, the next load would be 39.0 gr.

This would continue until a flat primer would show signs of pressure. At that point...let's say at 39.0 gr. the primer was flattened, then there would be 3 rounds loaded at 38.0 gr. and shot at 100 yards over a chronograph. If the grouping was good and there was no extreme spread in the 3 different speeds, that would determined what the load should be for that rifle/bullet combination.

I have used this method of finding the "right load" for 2 of my rifles and it has worked flawlessly.

Has anyone every tried this process or heard of this method?

Thank you, Bowhunter57

 

[morcey2]

By the time you start to see flattened primers, brass flow, or other "high pressure signs," you've already blown right past "high pressure" and straight into "hold my beer and watch this" territory.

Usually.

Depending on the primer, it can flatten at normal pressures (soft primer) or not flatten even at extremely excessive pressures (hard primer cup). Also, pressures don't go up in a linear fashion. Going from 37g to 38g might raise the pressure 1500 psi (2.5% on a 60000 psi load), but going from 38 to 39 might jump it another 6000 psi, or about 10%. At that point, you're pushing the 70000 psi range and that's definitely not a good thing. Those numbers are approximations from an article I read a couple of weeks ago. A 1g/2% increase in a charge was causing a 10% increase in pressure. I'll try to find it.

If you're going to be pushing things that hard, don't expect your brass to last long and don't let _anyone_ shoot those loads in anything else.

There are usually multiple accuracy "nodes" for a rifle. One of those nodes would probably be within the min-max range. You would have to do some shooting to find it, not that shooting more is a bad thing. That would be much safer than chasing velocity for velocity sake.

Too much of a risk for me.

Caveat: If you find conflicting info such as I see between the Nosler and Speer manuals where the starting load for one is higher than the max load on the other for the same powder/primer/bullet-weight combo, you're probably ok within the range of the higher charge load data.

Matt

 

[stavman11]

My question is...

Why would you want to max out your loads anyways?


i have pushed my .223 out past 3100fps... but find a better accuracy around the 2800-2850 range...

Now i could see in say a .357 magnum load pushing it for the BIG BANG effect... but not sure i see the rational behind a rifle Round being MAXED out...

I agree with morcey2... by the time ya see pressure signs in the Primer it may be too late or way to hot

 

[JohnM]

Maximum dumb I call it.

 

[Comrade Mike]

What they said. I've yet to have a rifle the hasn't found its accuracy load within published data ranges.

Dancing with disaster may be fun, until you trip. There's really no point to excessive hot rodding. If you have to push a cartridge that hard to get desired results you should probably be looking for another cartridge....

 

[oneounceload]

I have NEVER gotten the most accurate grouping from any of my guns by shooting max loads; from .223 to 7mm RM and a few others in between the accurate loads were usually somewhere about 75% of max. Going above max and looking for signs that may or may not indicate anything or nothing at all is asking for a bolt blown back through the cranium....not for me

 

[Walkalong]

When you start low and work up the charge slowly you will find more than one "sweet spot" as you go up in charge weight. Stop if you see or feel anything that seems wrong. Pick one of these sweet spots at or below max.

Follow the load books.

 

[Andrew Leigh]

Personally I would not take your friends advice.

Conventional reloading wisdom starts with a low load which increases in fractions of a gram (0.3 / 0.4 / 0.5gr). The load will typically start at 8-10% below the maximum recommended load.

The Chrony should be used from the get go and the speed should be the initial judge of pressure and not the primer.

Primer flatness is just one sign of overpressure and not always the best indicator.

There are in my opinion better methods that will reveal more about the load and the accuracy of the load. Google Dan Newberry's OCW method, it works a treat. To go max load and then to backoff from that is not great wisdom.

 

[RandyP]

Like yer momma probably said "If your friends go jump off a cliff are you going to follow them?"

Very, very few injuries or 'blowed up' guns have resulted from reloaders staying below the published maximum loads for their calibers. Why on earth would someone feel compelled to risk eyes, hands and their firearms just to prove Darwin right?

 

[243winxb]

Pressure Signs

Get to know All the pressure signs. http://www.thehighroad.org/showpost.php?p=8953638&postcount=31

 

[gamestalker]

I have been working with bottle necks for a long time and have always chased accuracy at the highest velocity that is practical and safe. With that said, I use a chronograph, I pay close attention to bolt lift, close inspection of brass following every round fired using a magnifying glass if I'm getting up there, and I use one brand of primer, CCI. I don't rely solely on primer inspection, that is a very ineffective method of reading pressures. As said already, by the time you see top hat primer flow, it can be too late.

And if I'm approaching the upper end of the load table I reduce my charge increments to .1 or .2 grs. I do not jump full grains once I'm above the half way point. And depending on how far off the lands you are, pressures can rise very quickly, and some what unpredictably as well. There are other variables that must be considered when playing with pressures of this magnitude too. I won't bash your experienced friend, but if he is relying on primer appearance alone, I wouldn't want to be standing near him when he is running his loads.

GS

 

[gamestalker]

Good stuff 243winxb!

And also I wanted to add that, depending on what head stamp brass is being used, some signs may not present before a catastrophic failure is experienced. And each time brass is loaded it changes in hardness, and develops incipient separations that require an experienced eye to identify.

GS

 

[ess45]

All my accurate loads are below maximum.
Accuracy is more important to me than velocity.
BTW, I only shoot paper targets.

 

[Bowhunter57]

I sincerely appreciate your replies, gentlemen!

I didn't like this idea/method of reloading and it sounds like I've been horribly misled. When I said that "I've tried it...", I meant that I was at their reloading facility and it was being tested there. Just the same, from what information you fine folks are passing along, I was in a seriously dangerous situation.

I have 2 new rifles that I'm currently working on getting the most accurate loads for and I have not come close to the high range/limits of the reloading data and am obtaining decent accuracy. At the moment, I'm working on bullet seating depth to find what the rifle shoots the most accurately.

Thank you, Bowhunter57

 

[Comrade Mike]

I have one rifle that shoots best at a max load. Everything else is about 10-20% under max usually.

 

[medalguy]

From The Free Dictionary:

max·i·mum (mks-mm)
n. pl. max·i·mums or max·i·ma (-m)
1. The greatest possible quantity or degree.

2. An upper limit permitted by law or other authority

It's called "maximum" for a good reason!

 

[flipajig]

With all my rifle reloads I work up in 1/2 grain incriments and usually .010 off the lands when seating the bullet.
Every thing is shot over a chrony usually you will find a sweet spot before you hit max. Valosity isn't every thing and for most the shooting that we do there shouldn't be a reason to push things that hard. The harder you push the round the harder it is on you and your gun.
Flip

 

[Captcurt]

Also take ambient air temp as well as barrel temp into account. Some powders are temp sensitive. A load that shows safe pressure at 40 degrees may lock the bolt at 90 or during a long session that heats up the chamber. I had one Max load that was fine in the winter but made the bolt tight when it was 80 degrees.

 

[ranger335v]

IF I had a "system" for exceeding book max there's no way in hades I'd tell it; anyone seeking guidance to exceed book max is far too inexperienced to do it. And there's precious little to be gained with hot loads anyway, the hazards far out weigh any potential small benefit; if you want more speed get a larger cartridge. :banghead:

The ONE thing I'll tell anyone is that primers are the poorest "pressure indicators" avaiable, we can blow a case apart and the primers may still look fine. Most badly "flattened primers" are due to excessive shoulder set back during FL sizing anyway but IF your flat primers are indeed due to excessive pressure the loads are vastly too hot.

 

[4895]

I believe that if you are going to load beyond published, tested, scrutinized loading data, that you are entering into the realm of experimentation.

I have heard that the current published load data is as much as 10% below the actual max. that was published a few decades ago. That being said, I only use current components with current load data.

If I were to go beyond published data, I would make smaller incremental changes rather than 1.0 grain jumps.

As has been mentioned here and before, most of my records indicate that 'target ammunition' precision is better with loads below maximum threshold. If I wanted to wring out every bit of power from a load, say for hunting, I could see pushing the boundary. In doing so, I would have to accept that brass life will suffer, shot groups will open up, throat erosion will necessarily increase, and damage to firearms and/or myself and others is inevitable.

P.S. I have blown out primer pockets with below book max loads to where the brand new brass was trash after the first firing. Just another reason to ladder test.

 

[Jesse Heywood]

Thus far no one has addressed the science. Before the wonders of computers, measuring pressure in a chamber was done by inserting a calibrated strip of copper between the cartridge and the cheamber.. After the round was fired, the thickness of the copper was measured and the thickness reduction in the copper was meausred. This gave an approximate measurement of the maximum pressure. It was during this time when maany used reading the cases for a maximum to back off from.

In today's world pressure measurements are made with electrical gauges connected to computers. With this advancement in technology, engineers are able to show a pressure curve from the time the primer ignites until the bullet leaves the barrel. The results are shown with measurements in p.s.i. (pounds per square inch). And a relationship between the pressure and measured velocity has been established. Since guns and barrels differ. engineers have recommended relying on the velocity measurement as the deciding factor in maximmum loads.

Thus, when working up a load, the recommended stopping point is when the maximum charge is reached, unless the maximum velocity is reached first. All of the old standards of looking for pressure signs by reading the tea leaves (cases) have been shown suspect, as they are only show a pressure way beyond the new maximum pressure readings.

 

[rcmodel]

was done by inserting a calibrated strip of copper between the cartridge and the cheamber..

CUP, or Copper Units of Pressure were actually measured using a Modern-Bond cannon-breech pressure gun.

The test barrels chamber was drilled, and a calibrated copper slug dropped in the hole in the pressure gun, than another fixture was slid in place and tightened down to keep it from blowing out.

After firing, the copper slug was measured for length, and a table was used comparing the measurement to a calibrated copper slug used as the standard.
How much it was compressed by firing gave the C.U.P units of pressure.
(Lead slugs were used for lower pressure shotgun, and the resulting pressure was L.U.P., or Lead Units of Pressure)

Modern-Bond pressure test gun as used by Hodgdon and most other manufactures:


Fired .223 Rem cases from Remington factory showing copper slug impressions.


rc

 

[Kachok]

I work up loads in a similar manner, but I don't exceed published maximum except in cartridges that are underrated max pressure in modern actions (such as 6.5x55) and I go up .5gr at a time rather then a full grain.
Unlike some here three of my rifles get their best accuracy at max load in at leased one bullet weight, my 6.5x55 like full house charges of RL19, my 30-06 like max loads of the same powder with 150gr, and my 7mm-08 shoots it's finest with a max charge of H380 in two bullet weights.

 

[mgmorden]

My question is...

Why would you want to max out your loads anyways?

That was my thought exactly. I don't get how some people came across the idea that the max load they could manage in a rifle was somehow the "best" load. Its often not the most accurate. Its not the most economical. Its not the most pleasant to shoot. In terminal performance on game it often has no meaningful difference (game hit by a bullet at 2600 fps isn't going to be "more dead" if hit by a bullet at 2700 fps).

There's generally no reason to ever exceed published data.

 

[wankerjake]

I don't understand NOT to wanting to maximize performance in you rifle, especially in a hunting rifle. Often times there are 2 accuracy nodes in a set of load data, and I aim to find the one near the top. I generally load foulers at min charges to check pressure, but don't start looking for accuracy until mid-way thru the data. Inside normal hunting distances, I'll trade a slight decrease in accuracy for more speed. And that's assuming the lower accuracy node is more accurate than the higher, which is not a valid assumption. Will a deer or elk notice a difference in a few hundred feet per second? Maybe or maybe not, but I'm gonna put the animal to the task.

It's a rare occasion that I can't find a good accuracy node within the top 30% of the load data. If I don't find one with one powder, I'll try another before opting for a minimum charge. Unless of course I'm aiming at low recoil, or I'm hunting game small enough for it to genuinely not matter. Case in point, my prairie dog load in 223 is on the lower end of the data. Accuracy matters most in that application, and it still makes them go splat.