6.5x55 In A Strong, Modern Action
- Thread starter Redhouse
- Start date
Largely a function of improved methods of pressure testing. The copper crusher tests didn't show the very short pressure spikes very well. Really good article on it in the Speer #14, called "Why ballisticians get grey hair."
Also, powders change over the years. Alliant 2400, I believe is one of the better examples of this. That and Unique, though there are a lot of others.
Or it's just a conspiracy and lawyers don't think you're as awesome as you used to be.
peterdobson, the specs Lapua regarded to, must be in the 50,000psi range. The 96 mauser actions, were used for many high pressure cartridges. I have seen them made up on factory built rifles, in 7x57, 8x57, 6.5x55, 9.3x63, 30-06 and even 308Win. The Norma and Lapua loaded ammunition for these rifles, really makes them perform to a much higher standard than North American loaded ammunition.
I would really like to see their tolerance figures. I don't doubt you one little bit by the way, so please don't take it that way. Some figures would go a long way in determining loads for some of these cartridges. I shot some 160 and 140 grain milsurp ammunition and it was certainly more snappy than any of the commercial stuff I could find loaded here. Even the old "Dominion" 160 grain loads, were anemic in comparison.
I would really like to see their tolerance figures. I don't doubt you one little bit by the way, so please don't take it that way. Some figures would go a long way in determining loads for some of these cartridges. I shot some 160 and 140 grain milsurp ammunition and it was certainly more snappy than any of the commercial stuff I could find loaded here. Even the old "Dominion" 160 grain loads, were anemic in comparison.
While it is probably very true that we have a better understanding of the pressures involved, it doesn't mean that we need to drop everything because we found a spike that has always been there and didn't cause actions to blow up for the past 100 years.
Just as finite element analysis allows us a much better view of stresses in structures and machine components, all the better pressure testing data does is show us a better picture of what has been proven safe for decades under actual use. It just means that the actions had a higher capacity for the peak pressures than previously thought.
Mark
I will give you one thing, the minneapolis 35W, made in 1967 using the best available technology man had on offer, collapsed. The Brooklyn Bridge, over built by slide rules and best guesses in 1883, is still there.
I honestly don't think all the precision we use in our day to day lives is particularly a good thing. A bunch of engineers get together and decide exactly to the 15th decimal place how cheaply something can get made without falling apart and killing people, which inevitably leads to people using things as not intended, and those same things falling apart and killing people.
As much as a load may be perfectly safe to use, the fact that for half a nanosecond, pressures spike to 150,000psi, makes printing that load a liability. The Speer #14 article really goes into this well, in that a lot of their favorite classic loads were showing up as unsafe, and they needed to figure out why. It'll likely take a few decades for all of that to sort itself out. In that time, one company will put their max up, another will have a max lower than the first one's minimum. It's a whole lot of very precise numbers and equipment, that even the best in the biz, don't always have the first clue of what to do with.
Remember, as well, these manuals, are intended to be used safely by the average person, and as George Carlin said, think how stupid the average person is, now think about how half the people are dumber than him.
That I can understand. Our society was not always so litigious and the companies can't afford to put out data that may ruin them.
Living on the edge, design-wise and safety factor-wise is OK if you can completely define your loads. What beats that is the misuse of items by people that don't understand what they are doing and how it affects the loads.
As noted in every manual, these are to be tested in your gun and developed carefully according to what your gun does. If you do that, it doesn't matter much if you get over a book max, as long as YOUR gun is not showing pressure signs and the chronograph isn't showing insane velocities.
Mark
