Max load question

[44 AMP]

I load for the same rifle

No, you aren't.

its the same make, model and caliber, but its not the same rifle!

This is a point that seem to keep getting lost. You, I, and every one of us is shooting a different gun and different ammo than the reloading data publishers used.

Even when we take pains to use the same bullet, case, primer, powder and bullet listed, our components are almost guaranteed to be from a different production lot#, and there ARE variations.

EVERYTHING has TOLERANCES, a min/max range and within that, things are acceptable. Canister grade powder has a range of pressure variance from lot to lot. Inside that range, it gets sold as Blasto#1 outside that range, it gets sold under a different name, possibly not as a canister grade powder, but in bulk to ammo makers.

Why does Hornady say one thing, Hodgon another, Speer another, Lyman something else, for "Max loads"? because each of them is testing DIFFERENT GUNS and DIFFERENT combinations of components.

And, lets be clear here, about "max loads", they are NOT the blow up point of the gun, not even remotely close. They are max safe WORKING loads in the gun tested.

They MAY be the same in your gun, They may also be above safe working max in your gun, or they may be below safe working max in your gun. Any of these is possible. You (and I) CAN'T know until we shoot them and see the results, which is why we start low and creep up.

Every different component plays a part and stacking tolerances can only be discovered by testing. Which is why we test, CAREFULLY.

 

[Metal god]

but they do not have the 139 gr bullet in them

First I thought , yes they do but double checked what bullet you were talking about

139 gr. hornady BTSP bullets.

and your right . the 139gr bullet in the Lyman manuals is the Hornady FBSP which has a longer baring surface . Interesting and let me give my opinion why . I've always disliked how Hornady has ALL the same weight bullet using the same data . This bothers me because some of the same weight bullets have VERY different profiles with very different baring surfaces .

Example I use the 178gr A-max often and can load over Hornady's max charge using IMR 4064

Originally Posted by Hornady 9th manual

{Edit: MG, please read the board policy on posting copyrighted materials. You covered the attribution, but you also need specific permission from the copyright holder and that has to be copied to one of the mods so it can be put in our records in case of a dispute.}

Clearly that 180gr RN bullet has a MUCH longer baring surface then the others . yet you are to load them the same . My theory on this is Hornady uses the bullets data that used the least amount of powder and says that's the max for all of those bullets . My guess is that 180gr RN bullet hit MAP at that 41.1 grains and that's the number they picked for all of them . I believe this is one of the reasons it always seems the Hornady manuals are a little on the lighter side of max charges on the whole .

Using that logic I still think you're good to work up to the 41gr mark and maybe drop that extra .5gr I suggested .

 

[kmw1954]

44 AMP, very good point.
I do not load or shoot rifles but that is irrelevant as the concept and principals are the same. I do have two 9mm pistols though and load for both of them and even though they are both 9mm they do not like the same ammunition. One I could load 124gr RN bullets out to 1.180" and they would chamber only they will not fit in the magazine. The other pistol with that same round I cannot load it any longer than 1.157" or it will not chamber.

I will also admit that I have run across a few people that do not hide the fact that they push the load envelope and at times will not take the time to work up loads. I also refuse to shoot with them. Now their loads may be perfectly safe but I do not want to be there to find out they are not.

One more thought about max loads or pressures. Western Powders on their pages have all the data for different loads, then separately they have the listing for the +P loads. Not all guns will handle the +P rounds but the info is out there to be used.

 

[jmr40]

For now, and until you get some experience and confidence stay with mid-level loads. When you get ready to work closer to max you can buy a chronograph for around $100. I wouldn't try to load anything much past mid-level loads without one.

For example my manuals say 46 gr of Varget in a 308 will shoot a 165 gr bullet to 2773 fps from a 24" barrel. The most important bit of information there is "2773 fps".

All the above info is accurate; start at about 90% of max; load a few rounds and shoot them checking for accuracy and speed. Moving up about 1/2 gr at a time repeat. In my example once I get above 2700 fps I'm getting close to my rifles max load regardless of how much powder I am pouring in the case. I've found the manuals to be pretty close with my rifles, that load gives me 2760 fps from my 22" barreled rifle.

But I've seen cases where a load with 44 gr of powder was giving 2800 fps and already overloaded even though it is still 2 gr below max. It doesn't happen often, but it does happen. Sometimes you load 46 gr and still only get 2690 fps. Every rifle is different.

You also have to account for shorter barrel lengths, so 2773 would probably be a little warm from a 22" barrel. Probably not dangerous, but on the warm side. Certainly too hot from an 18" barrel.

Trying to stay 2-3 gr below max might not prevent me from being over pressure. Traditional pressure signs don't even show up until you are WAAY over pressure. On the other hand I might be shooting 308 loads at 30-30 speeds and not even know it. A chronograph lets you KNOW what you are doing.

 

[Don Fischer]

Cola 308,

The general rule of thumb for rifle cartridges is to multiply the maximum load by 0.9 (aka, a 10% reduction) to get the starting load. There are some exceptions for technical reasons: some powders have different burn progressivity curves than others and don't need to be reduced as much; some powders don't behave well if you let them fill the case too little. But you'll find those in the data.

There are two general rules of thumb for handgun cartridges. The original one was the same as for rifle cartridges: multiply by 0.9. But Western Powders suggests that because the case volumes are small compared to rifle cartridges and because many powder dispensers tend to err by fixed amounts that are a bigger percentage of a small case volume than of a large one, that you multiply the maximum load by 0.85 (aka 15% reduction) for handgun cartridges. Again, there are exceptions among very slow powders. H110 and 296 (actually the same powder with different brand labels) is a magnum handgun powder that should not be loaded down too far because of the danger of it squibbing out and leaving a bullet stuck in the barrel that can cause a catastrophic failure when the next round is fired into it. But again, the load data for those powders shows their more limited adjustment range.

Every once in awhile you run across data for a cartridge with a particular bullet weight by one source that is completely outside the data from another source (no overlap). This is most often due to differences in the type of bullet construction involved. Here you want either to find data for your particular bullet (call the maker) or find the lowest starting load among the different data sources and start with the lowest once you can find. That is good advice in general/ I always check about three different data sources.

!0% down is what I've always heard. May not be needed but won't hurt either. When I start work on a new powder, I start about 5grs below max and work up to a half grain over, one round each in 1/2gr increment's. Then start at the bottom and shoot them into the ground. What I'm looking for is pressure sign's and I stop when I find them. From there I start two grs below max and work up three rounds each at 1/2gr increments. I would suggest either way for you if You know what pressure might look ike. If not, start 10% low and work up.

 

[Unclenick]

You always want to start with the bottom load listed and work up, watching for pressure signs.

My simple view.…If load data lists 4.0gr of whatever as the start and 5.0gr as the Max then all should be safe to load no matter if you've loaded 10 rounds in your life or 10 million.

Per 44 AMP's post, this is one of those cases where you can get make it too simple. A perusal of the load manuals will eventually lead to to examples where the starting load from one place exceeds the maximum load in another. In general, sticking with the bottom load will keep you safe. However, I've had one example in a personal weapon of an old Hornady manual starting load being already at maximum for my light revolver. I had case extraction getting sticky on the very next step. But that was from Hornady's 2nd edition which was published back before Hornady and other major manual authors had their maximum loads tested. We did have a fellow on the board two or three years ago who was using the most current, tested Speer data for a .243 Win load in a Handi-Rifle, and who was just past half way up the listed load range when the rifle not only started popping open (and he did check the latch was clean), but it was producing 200 ft/s over the listed manual velocity, so something went wrong in there. We had a third example on the Shooter's Forum of a maximum load producing loose primer pockets and pierced primers gas cutting pits into the bolt face, but it was also a couple of years ago and I've forgotten the load specifics.

An issue these days is the number of different types of bullets has grown and folks will think they are doing a proper job of following a load, but because of those differences you can actually get some maximum loads into proof load territory now by changing to a different type bullet of the same weight. A Speer technician told me the soft plated-on jackets in their Gold Dot bullets often make loads that are safe with them too hot for a cup and core bullet jacket. Unfortunately, since Speer and Alliant have the same parent company, a lot of Alliant's load "recipes" are only for Gold Dot bullets and can mislead someone with a same-weight JHP from another maker to run warm. Also deceptive, in my view, is their use of the term "recipe" making that listed load sound safe. It's only when you download Alliant's manual in PDF format that you learn those "recipes" are actually maximum loads and they want you to knock them down 10%.

So, there are some potential booby traps out there that you just have to navigate your way around. At the other extreme, there are also some true recipe loads that have been used safely for generations without load workups. 5 grains of Bullseye under a 230 grain FMJ in the .45 Auto. 4.2 grains of the same powder under 185 grain JSWC target bullets is another. 47 grains of IMR 4895 behind a 168 or 175 grain match bullets in the .30-06 for the M1 Garand or any other .30-06 is another.

I'll also caution again that some powders don't like to be loaded too light. Back in the 60's Dr. Lloyd Brownell documented examples of pressure randomly doubling due to loads having too little case fill. It wasn't consistent at all, but rather part of a noisy range of peak pressures produced by the loose fill. Some powders seem to be more sensitive to that than others, so going below the starting load is also to be avoided unless you know you can go there. The powder maker will usually tell you. There are exceptions: Hodgdon claims H4895 can be safely loaded down to just 60% of their listed maximums, where other powders cannot. It's a complex issue and there are always examples of exceptions. When in doubt, call the powder companies or bullet makers and they will usually help you. It's best not to take anything for granted.

 

[T. O'Heir]

"...should he stay away from max load..." No reason to not work up to the Max load by anybody. No loader should go above the Max load regardless of experience. Moreso if his reason is some nonsense about load manuals being lawyerfied.
"...they do not have the 139 gr bullet in them..." Just use 140 grain data. One grain of bullet weight will not make the slightest bit of difference. Three to 5 grains won't either.
"...because each of them is testing..." And under different conditions. The climate matters. So does altitude.
"...46 gr of Varget..." That being the current Max load and is compressed. Compressed loads being nothing to worry about. Isn't just the 46.0 that's compressed either. Compression usually starts a bit above minimum.

 

[kmw1954]

Nick, why is it you left out the rest of that comment? The part about basic rules and procedures?

I do believe on of the 1st basic rules it to always start at the bottom and work up?

 

[Unclenick]

I didn't find the rule to start low stated explicitly in that latter part of your post. You may have meant it implicitly by mentioning that there are rules to follow, but a Newbie can't be counted on to know that. We still have people with decades of experience post that they always start in the middle of a published load range, so that first basic rule has not got through to everyone. 99% of the time you can get away with that middle load range, especially if you are using the exact same components (not changing the case, primer or bullet and matching the COL). It's the 1% where it doesn't work out that you want to avoid experiencing.

 

[kmw1954]

WOW!

 

[44 AMP]

No loader should go above the Max load regardless of experience.

Sound advice. Which, if it was followed by everyone would mean we wouldn't have a .44 Magnum, Ruger Only .45 Colt loads, the .454 Casull, and a several other useful cartridges and loads.

No driver should exceed the posted speed limit, regardless of experience.

Also sound advice.

Do YOU live by it?

I usually try, but sometimes, I don't.

 

[std7mag]

I'm over max load every time i pull the trigger on my 7mm-08.
But then again mine has been "improved". And i have yet to find any RELIABLE, safe published load data for 7mm-08AI.
The load data found online is WAY too hot!!!

 

[HiBC]

It helps that you are using what I will call "balanced" cartridges. The boiler room powder capacity is balanced to the bore diameter.If you want to research it farther,look up "expansion ratio" and "overbore"
These cartridges are more forgiving than something like a 25-06 or 264 magnum,etc.

Manuals (Sierra,for example) may offer "recommended hunting load" and "recommended accuracy load" You still need to work up to the load,but they help select an optimum powder.

You CAN find some bullets that will dramatically increase pressure.The very early "Nosler Solid Base" comes to mind.They are discontinued,but I experienced them.

I look at it reloading sometimes as dancing near the edge of a cliff. If you have aprimer or case failure,you went over the edge. It can be fatal.

The manuals do their best at letting you know where the edge of the cliff is,with some necessary margin for error.

You really need some margin for error.Powder batches have variance lot to lot.Bullets vary a bit.All the components do. Your bore is more or less metal fouled.Its a hot or a cool day...or barrel/chamber.

Add to that the variables in your reloading process.

The person who buys powder 8 lbs at a time,bullets 1000 at a time,cases500 at a time has reduced lot to lot variation.That CAN reduce margin of error requirement,for example.

Get one of the nice reloading log books. Write down what you learn from each loading.

A $130 chronograph is an excellent investment.Mine is a CED.It has served well. If max load vel is 2780,its a clue if you hit 2780 one grain below max.Pressure makes velocity.You hit max pressure.

Study the ballistic tables in tho books,or use software.Find out what that last 50 or 100 fps actually gains you in "max point blank range" or in max range to hold 2000 fps.

Think "diminishing returns" The last 1.5 gr of powder or the last 75 fps are "intense" and they really don't gain you much.

Your brass lasts longer.Your barrel lasts longer.

I DO load for performance. But a lot of that comes from choosing the best powder,efficient bullets,etc.

I suggest as a beginner, consider how much margin of error you want.Gain experience.Gain data in that logbook. Get your process and confidence down.

With your rifle loads,I suggest working up to a couple of grains under max with your rifle..for a while.
Maybe think midrange to 90% in the 9mm,depending on function.

Be safe! Only one powder on the bench,read the label out loud,twice!!

The Big Bang most often comes from loading the wrong powder.

 

[44 AMP]

If max load vel is 2780,its a clue if you hit 2780 one grain below max.Pressure makes velocity.You hit max pressure

MAYBE

And, maybe not.

Pressure does make velocity. BUT, it does NOT do so uniformly in every barrel. There is a relationship between pressure and velocity, but it is not linear in any one gun, and not consistent from one gun to another.

It is a general thing, more pressure means more velocity, but beyond that, every gun can be a different individual.

Lets take that max load vel of 2780fps, for an example. You got data that says max load is 2780fps. Fine.

I have 3 rifles, as identical in all aspects as we can make them, shooting the same ammo, again, as identical in all aspects as we can make it.
Rifle #1 shoots 2780fps
Rifle #2 shoots 2730fps
Rifle #3 shoots 2830fps

Identical rifles and ammo (as close as possible) different MV speeds.

Which one is overpressure???
(the reality is that velocity alone, only tells you velocity)

suppose I'm shooting a gun with a barrel 4" shorter than the test gun in the loading data? I may never get to see 2780fps. Does that mean I'm never going to be overpressure? (Answer, NO, it does NOT mean I will never be overpressure)

All kinds of factors are involved, which means you cannot tell FOR CERTAIN if a load is "overpressure" simply by velocity alone.

And, equally important, overpressure compared to what????

SAAMI specs?? What are SAAMI specs?
They are a number agreed upon by the gun and ammo makers as a safe place to stop for ammo that can work safely in EVERY GUN chambered in that caliber,

It's NOT the edge of a cliff, its more like the edge of the cleared, level playing field. Yes, somewhere out there, beyond the edge of the field IS a cliff. But between the edge of the field and the cliff there are rocks, and sticks, and hillocks, and rabbit holes and cowpies, and other things that impede your running downfield.

What you are "driving" matters. A lot. Cars aren't a perfect analogy, but I think they can come close, sometimes.

lets say there is a SAAMI speed limit sign on a curve that says 40mph. I can take that curve with anything on the road from a sportscar to a semi truck at 40mph, safely staying on the road, and in my lane.

Now, I know from carefully "working up" my speed on the curve, in my sports car, with its low center of gravity and tuned suspension, that I can take that curve at 65mph, and stay in my lane. BUT, in my 3/4 ton pick up truck, if I take that curve at 50mps, my truck drifts to the edge of the road. AND, because of that, I know that if I tried it with a semi, over the posted speed it would actually be dangerous.

And, getting back to guns, even within SAAMI specs there are adjustments that often have to be made for different guns. Ever hear of some hot loads (but still within SAAMI specs) working fine in a bolt action, but jamming a semi auto because it couldn't extract the fired case??

All reloading data is GUIDELINES, its accurately telling you what they did, and what they got for results. Your gun, and your ammo may be essentially identical, or they may be significantly different.

This is why, even WITHIN published data guidelines, we work up loads, carefully and slowly in small increments of change, to ensure that what they got and what we get are similar enough to live with and be safe, and why when they are different, we STOP and figure out why they are different, and what, if anything, we can do about it.

 

[HiBC]

Agreed. Language and metaphors have their limitations.
And I did vastly oversimplify the velocity/pressure relationship.

Barrel length,polygonal rifling,etc aside,the point I failed to express well,there is no guarantee I will achieve published velocity.I may get a sticky bolt handle 150 fps short. Time to pay attention.

But if I'm relatively new to loading,(or experienced!) and 47 gr of RE-19 is supposed to give me 2780 fps,and I get 2925, I can assume I have a "Special Gun"....but it might be better to say"Whoa!" Why is this happening?

If the data was tested with a 22in bbl,and I have a 26 in bbl,OK,I understand.

But it MIGHT be time to look at temps,or check my scale calibration,etc.

There is no free lunch.

In any case,we get little indicators,clues. Its good to pay attention.