How safe is published maximum load?

[hatari]

I'm a loader by necessity, and know it's against safe practice to not working up to maximum load. However, because of limitations, I've beenh using maximum loads, and got away with it. My favourite load being the Pet Load from Ken Water for 7mm Rem Mag, 150grains Nosler Part. This is quite above other published datas.
My question is how safe is it to use Nosler published maximum loads in commercial rifle such as Sako, that is quite new and in excellent condition, never abused with heavy loads.

 

[Ol` Joe]

The short answer is I wouldn`t advise it. You may get away with it for years then one day pop a primer or worse.
Loads listed as max are only max for sure in the rifle they were developed in. The load could well be under or over in your rifle, and the components used in it development are a big part of the load and are not likely to be the ones you are useing either.
Powder companies try to keep powder burn rates within a +\- 5% range. This appears as a possible 2.5gr difference in max powder charge all else equal just from a lot change in a 50 gr powder charge. Bullets can and do change at times, as does the core and jacket hardness. Case capacity of a Federal case isn`t the same as a Winchester if you happen to have to sub one for the other. You rifles throat condition, chamber geometery and temp, humidity, ect can also cause pressure to vary.

 

[tjRoberts]

In the 7mm rem mag,
I would be carfull. The loads listed as max are at or near the maximum presure for the cartridge, as are factory loads.
I usualy start about 3 grains below max in that situation.
Loading down a grain or 2 will not have any real effect on your velocity.
You might lose 50 to 100 FPS.
It makes little sence to take a chance like that with little to gain.
In the case of some other cartridges, you can be a little more agressive. For example, I have a ruger #1 in 7X57. That is a very strong modern action.
The Preassure specs for the 7X57 are set for 1892 mausers at I think 45,000 or 48,000CUP.
When I bought my Ruger, I started at the max listed load and workrd my way up. I Stopped one grain over the listed max from my Nosler manual.
I am sure I could go up safly but I would gain so little it makes no sence.
You have a great rifle if you have a sako in 7mm Rem Mag.
No need to ring each little bit of bullet speed from it.
What weight bullet are you shooting ?
Check the trajectory tables in the back of the manual and see how little difference 100 FPS makes...tj3006

 

[DrMike]

Ol' Joe is right. Add to that the variances in tolerance allowed in bores, and you are tickling the dragon's tail. Pressure mounts exponentially rather than arithmetically. Though powder and bullet manufacturers are careful to pressure test their loads, you will note variances between published loads. This is the reason all advise starting with a lower charge and working up to maximum, watching for pressure signs. It does happen.

 

[Antelope_Sniper]

I took a close look at the Nosler #6 when I bought it.
Some of the loads looked pretty cold. Nosler has a reputation for being pretty conservative with their load data.......but some of the loads.....looked pretty darn hot to me.....If you are new to loading, don't know you rifles, and don't have enough experience to know which component substitution will spike your pressure, then DON'T DO IT. Sometimes I may use a powder charge over the listed max, but it's usually because I have substituted other componets that I know will lower the pressure, so that it should net out. Of course I never start at these levels.

 

[blacktailhunter]

Great advise so far. A few years back, one of the shooting magazines had an article about testing pressures on handloads. I don't recall the number of rounds tested, but in general, they took finished loads that shooters were using in their rifles as their primary loads. Many of the loads were out of Ken Waters Pet Loads book, some were referrenced by Jack O., some were published max loads, and some were below listed maximums. The loads were then tested for pressure using modern equipment. The average working pressure for the loads tested was just over 75,000 psi! Just following the manual is not enough. NEVER start at maximum load! You need to use a chronograph and reference your handloads to factory loads at the same time. Scary loading practices are exactly why I never sit next to anyone at the range. I do not want gun parts impaling me because of someone else's stupidity. I will be very direct about this. You need to be more responsible in your loading practices before you injur yourself or someone else!

 

[JD338]

Generally, MAX loads are safe because of liability concerns. However, every rifle and conditions are different so you need to ALWAYS start low and work up to a MAX load while watching for high pressure signs.
You could reach YOUR rifles MAX load BELOW the published MAX load.

JD338

 

[hatari]

Thanks for all replies which reflect your concern for safety.

 

[RiverRider]

Many years ago, I got a little too comfortable and decided that I would just go ahead and load the max charges shown for .223 Remington using 50-grain pills and W748. When I began firing those rounds, I thought my chronograph was acting up because I was getting about 3600 fps. A careful look at the target showed something else was up, so I visited the target frame and was met with bullet holes that closely matched the bullet's profile, dispersed randomly all over the target.

I can only guess what the pressures were on those loads, but I think it's safe to guess that it was waaaaay over any kind of reasonable limit. I never did that again!

 

[hatari]

Thanks for additional info update. While I understand concerns for safety, I wonder about commercial loads by big names that have velocity right up there. They are subjected to liability, and shooters use them from artic to Africa . How do they get away with humidity and temp extreme variations? I'm aware that Ken Waters loads can be pretty at max in his rifles. What about Nosler manual which suggest general data for Part, Acub, and E-tip? I'd assume that Nosler woud allow some margin of safety. I'm not pushing to start at max loads, just hoping to get feedbacks.

 

[blacktailhunter]

Ammo manufacturers have access to very sophisticated testing equipment and can order/produce powder in huge quantities. The powders used might not even be a canister powder available to the handloading public. With their main objective to stay within SAAMI specs, often times accuracy and consistency are sacrificed.

As far as the Nosler load data is concerned, I actually fault Nosler for using only pressure test barrels longer than than most factory rifles that are being used by the majority of the shooters. What they should do is combine load data with their long test barrels along with load data from a factory rifle, like Speer using Ruger M77's, so us regulars can actually use their data for accurate comparison. Comparing different books is a big help, but it also can be a huge detriment since each bullet make will act differently even though all other components are the same. That's not to say that all the factory sporter rifles will act the same either, but it would be a better fit for the average hunter to reference.

Also keep in mind that there many people on the shooting forums like to add about 75-100fps and cut their group sizes in half when discussing a favorite load. Just be sure to pay attention to what your rifle is telling you and not making it fit into another person's on-line rifle.

 

[Richracer1]

The above post is why, I'm assuming, a lot of us post pics of our targets to go with the load info we're sharing. Posting a pic of your target prevents the online boasting of how fast and accurate a particular rifle is.
Also take into consideration, that just because a manufacturer publishes and certain grain of a certain powder in the most accurate or had a specific velocity, doesn't mean it'll be accurate or that fast in your rifle. For instance, sometimes my rifle will shoot a specific recipe a little fast than published, but usually it's a little slower, but I always start low and work my way up in half grain increments. This takes a lot of bullets, and even more time at the range, but it works for me.

 

[Greg Nolan]

All the above is good info.
I have always considered Nosler loads to be conservative so I started about 2 grains below max and worked up. This worked for about 45 years untill my new 22-250. At 2 grains below max it blew the extractor and jammed the ejector with a serious overload. I checked the loads on my cartriges and they were correct and I measured each load initially so I know they were the same. Just the difference in rifles. I had used that same load but at max in another 22-250 for over 35 years with no problem. It is better to work up from mid range.
I do have several loads that are a couple of grains above max listed but I worked up real slow and checked a lot of rounds before I declared them huntable.

 

[jtoews80]

There are also some signs to watch for even if the pressure is controlled by a slow burn rate powder. If velocity stops climbing as you increase you charge volume it is likely that you have reached the velocity potential and will not go much faster with that powder, all you will do is wear you throat out with that pressure/temp of load.
More velocity than expected is a serious sign and has already been mentioned.
Other things to watch for are barrel heat, if it heats up faster than normal you may be using up alot more barrel life than needed. And of course, as was mentioned, accuracy. If you velocities are uniform and at a safe pressure, it should be accurate.

JT.

 

[Ol` Joe]

As far as the Nosler load data is concerned, I actually fault Nosler for using only pressure test barrels longer than than most factory rifles that are being used by the majority of the shooters. What they should do is combine load data with their long test barrels along with load data from a factory rifle, like Speer using Ruger M77's, so us regulars can actually use their data for accurate comparison.

I don`t fault Nosler too much for this. If one looks Hornady, Sierra, and Speer all show velocity from various rifles in place of test barrels, and none of them match up. They get the same type results from various rifles you will. Without chrono`ing your load in your rifle the velocity is anyones guess.
Taking Speer or ny other books velocity as being truer then Noslers is like accepting my rifles velocity as being better. A test barrel is much more uniform and the results "should" be too. if everyone used them for their velocity claims they would all be much closer to comparing apples to apples then they are today....JMHO

 

[.405]

I have a lot of older manuals as well as newer ones.It seems that the published maximums in a lot of calibers has shrunk over the years.Liability issues I am sure.
I have been shooting loads for years that are above the published maximums in some manuals.This is with no signs of excessive pressure.
It is wise to start conservatively and work the loads up.