Hey guys, I have a question regarding MAX loads in reloading books. On average, how many grains do you guys go over the suggested max load in the manual. I am just curious to see what you guys think. It seems like many reloaders go over the suggested max load by an average of 2 to 3 grains. Does that seem about right?
Alot of guys get away with this practice but it is always well advised to start well below the max load. I know a few guys that start at the max load and work up and one of them galled his bolt shut in a rebarreled Sako one time , the chamber was very poorly cut and had headspace issues so I'm told the the first round was a max load out of the Nosler #5 book.
The companies get their "max load" by using pressure barrels and when the pressure reaches a set point ofr that round they stop their. If you look at most manuals their accuracy load is typical not the max load. Although I have seen several Weatherby's shoot better and better as the pressure rises up to the point of sticky bolt lift , I think that this has to do with their chambers having freebore.
I believe that 65,000psi is about the max for most modern rounds out their , I had a 30-06 Ai that had a tight, perfect chamber in a Holland built Rem 700 and when I finaly got my "perfect"load it was well over max of R-22 the velocities out of a 26" Hart barrel beat any 300Win mag load. I talked to several tec support guys for differant powder makers and they all said that the pressure was probably around 75,000psi. That was when I was younger and alot dumber when speed was the main objective.
I read about this in an article written by Rick Jamison of Shooting Times magazine.He did some testing to find out if the listed maximum load on several reloading books were really maximum. His result were conclusive. Majority of the listed load were endeed maximum. Few even went beyond maximum SAAMI spec. He used 30-06 rifle and the Oehler 43PBL for his test. We all know that no two rifle are the same. Maximum pressure on my rifle doesn't necessarily mean maximum on yours. My 280 Remington load of 56 grain of IMR 4831 to propell the 150 grain Nosler Ballistic Tip close to 3000 fps is beyond maximum on any reloading book except the old IMR reloading pamphlet.No sign of high pressure at all. Most of the brass that I used on this rifle were reloaded more than a dozen times. The load for my 300 Win Mag Model 70 Laredo using 180 grain Hornady BTSP according to Hornady 4th Edition Reloading Manual should never exceed 76.7 grain of H1000 but according to Hodgdon it should be 83 grain. Well I found the middle ground, I used 81 grain and even that it's probably redline. But who cares, the rifle groups half inch or better. The bottom line is, you could probably push the envelop a bit with careful handloading but is it worth it. Unless you are willing to attached a strain gauge on your rifle you will be sailing in an uncharted water buddy [img]/ubbthreads/images/graemlins/frown.gif[/img]
To achieve the maximum possible accuracy, all variables must be remove or at least minimize.
Heed the info already posted here. As has been mentioned, manual testing is done using the right equipment to determine the pressures.
This said, I like some of the others, have a couple of loads which do indeed push the upper end of the spectrum in the books. One in particular is for my 25/06 using a 115gr Partition. I moly coated them and when they were purchased I bought 10 boxes of the same lot. The powder and primers are all from the same lot as well. Once it is done, I will back down and work back up. If I get to the same load great, if not, I will be happy with what ever I get as long as the groups are there.
I also have several which will only get to about 2/3 of the top listed loads. I simply look for a good velocity, with the best groups I can get from it. I really rarely push the issue.
Over the years, I've heard from many folks who go 3% to 5% over listed max. Sometimes, they'll go 10% over max. Sometimes they get away with it. Sometimes they don't.
I talked with a technician at SAAMI not too long ago about this very thing. He agreed with me regarding the following: if you can't reload a case more than 10 to 15 times without its primer pocket getting too loose to hold a primer, that set of components in your barrel is too hot for reasonable safety margins. Something's making peak pressure too high and it's prudent to cut the powder charge back a bit.
There are those among us who insist on shooting hot loads that get less than 5 firings per case. And they'll say anything they can think of to justify their position. Different signs of peak pressure are used by folks developing and publishing load data. Most of them are subject to the whims of the developer; few are based on accurate and real pressure test barrels with SAAMI standard bore, groove and chamber dimensions. And if a reloader uses a different barrel as well as set of components, even with the same make, type and number, their pressure can be too high or low enough that another grain of powder or two could be used.