Is there any reason to go to max loads?

My experience is that it varies with the powder and bullet in use. My wife's .243 is the best example. With 85 gr bullets and h380 I wound up with 37.1, almost perfectly in the middle. With 4831SC I again wound up in the middle. With 95&100 gr bullets and h1000 my target looked like a shotgun blast (with much trepidation too) until I got to the final test batch at .1-.2 under Max and BAM holes touching with zero pressure signs. Now that deer season is over and I've successfully completed that mission I'm going to play with lighter bullets and various powders for varminting so we don't use up so many of her deer loads. Time will tell but I don't aim for the Max on any load when I start.

 

I've got a couple of powders in pistol that I load at max because I get better burn of the powder and better accuracy. I've also got some I load at minimum and they work great.

 

One that always end up at max for me is 357 mag when using 296/H110. It is an oddball where highest velocity and best accuracy meet up in the same place at or near max charge.
In rifle loading I usually end up one or two grns under max for best accuracy. At that point another 25-50 fps loses out to smaller groups. I still fire through the full load so long as pressure signs don't develope but usually see a consistent closing in group size around mid charge followed by widening. A more experienced loader taught me to check 3 sources for load data due to variances and start with the average of the three.

 

I will load to max and beyond if I want max performance out of a cartridge, accuracy remains good and pressure signs are ok.

I wouldn't say I go over book max often but I've done it. Generally with hunting loads for example I go as close to max as accuracy will allow and if accuracy isn't there at the top end of the data I'll switch to a powder/bullet combo that will get me there. There's a time and a place. Sometimes I want the maximum a cartridge will get me. The point of hand loading is tayloring loads to YOUR needs.

When I'm looking at economic range loads then yeah, close to min as possible.

 

I only have one factor that determines my load (assuming of course it is within the suggested range). Accuracy.
The only way I would load a max load is if it were the most accurate load in that particular gun.

As for a safety net, that is built in when a company is determining the max load. They build in a buffer.
With that being said, you should always work up to a max load, not just start there.

 

"...load data in manuals..." Are averages, not the actual data collected during the tests. There is no such thing as "lawyer loads". All load data in every manual varies by powder lot, the firearm/universal receiver and other conditions on the day of the testing. What is the current Max load can be different(higher or lower) 5 years from now.
As mentioned, if the Max load is the most accurate, use it. There's no inherent danger.
"...at a starting load and work DOWN..." Below minimum loads can be as dangerous as above max loads.

 

I'm usually pretty close. But I use a chronograph. Typical factory 308 loads are around 2800 fps with 150 gr bullets. There are several loads that are perfectly safe, and quite accurate I might add, at closer to 2900 fps, without exceeding loading manual specs. You can often beat factory 30-06 speeds perfectly safely by more than 200 fps with published loads. My criteria is all the speed I can safely get and still keep 3 shots inside 1". I often get groups much smaller, but if you can put 3 in an inch any game animal you miss inside of 400 yards is shooter error, not rifle or load error.

Where guys get into trouble is playing too close to the edge with no chronograph. The loading manual may say 47 gr = 2880 fps. But I stop when I get to 2880 fps regardless of the powder charge. It might hit 2880 at 47 gr, it might hit that speed at 46 gr.

A lot of hand loaders err so much on the side of caution that their loads may not even break 2600 fps. There is no sense in that.

 

I basically load 25-06, 270 Winchester and 30-06 and I have found that if I stay 2 grains below the listed max load for a particular bullet and powder combination that I have a safe load. Because I am a hunter I do creep up toward the max with some combinations to find the sweet spot. I pay particular attention to pressure signs and case life and I gravitate to powders that give high velocity and long case life. I am particularly fond of Sierra GameKing bullets and powders like Reloader 17, IMR 4064 and Reloader 22. I am currently testing loads with Reloader 16. Higher pressures and inconsistent accuracy can be caused by hard case necks and inconsistent bullet tension from the case neck. I use new cases and anneal often to keep the necks soft.

 

What load is that?

I'm asking because according to the Hornady manual #4, a max load for 55gr jacketed bullets is 21.1 grains, but Hornady manual #8 lists a maximum of 20.0. Neither edition of the Hornady manual lists pressures, but Hodgdon's manual #25 says 20.5 grains yields a pressure of 48,600 psi while Hodgdon's current on-line data says 20.4 grains produced 53,600 psi. I load a lot of .223 with 4198 and just wanted to know where your maximum loads fell with respect to the various published "maximums".

 

The load I use: 21.5 gr of IMR4198 is listed as max with a 55gr FMJbt in Lyman's 45th, and Lees Modern Reloading, as well as the "real world, in my rifle" data I inherited from my dad.
I haven't had any problems with this load cycling, or with pressure signs, in either a 20" rifle, or 16" carbine (AR)
Primers flatten a bit, but ...meh. It is slightly more accurate in the rifle than the carbine.

So I treat it as a "max" load. However;

In my Speer #8 & #10, max is listed at 22.0 (both of these have some HOT hot loads in them)
And on the other end,
In Hornadys 7th edition, max is listed at 20.0. I've found this book to be full of powder puffs (relatively speaking).

When I refer to published data, I tend to throw out the highs and lows, average what's left, drop down .5-1.0 grains, and start from there to work up. That way, I shouldn't blow anything up, and it won't take me a week to run through test loads. (10-20 rounds each, in .2gr increments can take a while)

Because of the extreme variance found within the published manuals, it's good to have as much data as you can get your hands on to work with- said Captain Obvious

For reason I can't quite put my finger on, I like IMR3031 in the AR a little better.

 

You have to examine their test chamber/barrel very closely as to OAL. I've seen many examples in one book have a max load of 4.4 gr and another 4.9gr on 45acp. When you at the detail, 4.4gr had a very short OAL of 1.200 where the 4.9gr had 1.275". That's a huge swing in OAL which we know in the high pressure rounds that 0.030" shorter change can double the pressure.

Have to look at the details.

 

It depends on the application of course. For plinking at 100m I tend to use the most accurate load whether it's a minimum load or a maximum load. For example, shooting 155gr bullets in my .308 has excellent accuracy at 100m with a velocity of 2,400 fps (20" barrel) which isn't very fast, and the powder loading is closer to min loading than max.

However, when shooting long range (~1,000yards) I aim for a good, decent velocity with a low extreme spread. For example, with my 6.5x47 Lapua I aim for a velocity of 2,900fps with 123gr projectiles which just so happens to be just below the max published load. I have a decent ES of 14fps which works well for me.

Keep in mind that some of the published maximum loads are anemic. I don't think any powder manufacturer would publish load data where the firearm would have a catastrophic failure 0.1gr above the maximum load. I still don't think it's a good idea to go over the published load though, the companies that produce load data have done the hard work for you by creating a window for you to work in.

 

Believe it or not there are some propellants that give me pierced primers with starting loads in my Rem 700 .223 with 30" bbl and 12" twist, if I'm using anything heavier than 55 grain bullets. But with 55 grainers I've been getting close to maximum with Varget. This for target shooting only.

 

I rarely go with max loads. When I do, it's in a bolt gun that exhibits the best accuracy there, when working up loads. So far, that's in one rifle out of the dozen(+/-) that I own. IMO, there's not much dumber than loading hot, just for the sake of having hot loads.

 

The gun will tell you what is right.

PapaG,KingMt, ArchAngelCD, Dog Soldier. have good comments. Approach incrementally.

Bart B. has some good thoughts, too. The gist is (and what I think they are saying) is that max loads are tuned to the particular firearm in which it was developed.

When the loads in the manuals were developed, they were tested in particular firearms and the min/max range was based on SAAMI pressure specifications (however the testing lab figured that out) to be safe in the average firearm in good condition chambered for that round.

You firearm may have lower pressures or higher pressures due to its particular dimenstions;.\

The manuals strive to stay safe in any firearm. But, as reloaders, we take our own responsibility to work up loads safe in whatever firearm we are using. Even if our firearm's chamber produces pressures above max (watch for the tell-tales) by below minimum published data. WE ARE OUR OWN BALLISTICS TESTING LAB!

Each firearm has its own rule.

Lost Sheep

 

Depends - certain powders burn cleaner or more completely at max loads, though I rarely am concerned about how clean a powder burns.

In general - I never worry about working up to the hottest load a gun will stand. If you by chance inherited or found a deal on one single gun and you wanted to make it something it's not (ie, loading up a hot .243 or something), then sure. However if I'm loading for .257 Roberts for example - I have no motive to try and load it hot, mess with AI chamberings, etc. The whole reason for owning that rifle is to have something more mild powered. If I want to shoot something more powerful I'd just grab the .30-06 or something else.

 

My Ruger .Auto .44Mag Carbine will not function with anything less than maximum loads of H110 or WW296 and a 240grn projectile, in fact I believe the reloading manuals recommend a full charge and a magnum primers using these type of powders. Note I've used 2400 also but found the most accurate powder charge was H110 or WW296 at full (maximum) charge. Definitely puts the wild feral hogs to rest in a hurry out here. Most of my rifle cartridges .223-45-70 I usually let off a bit as I've found that is my most accurate charge, and according to my chronograph is definitely within the parameters of performance.