USSR
Member
It never ceases to amaze me, the number of times that people pass on information that they have seen somewhere on the net, as established and irrefutable fact. And, one of the most common areas seems to be in the field of reloading and ammunition. So, as one of those guys that wants to constantly “prove it to myself”, here are some of the myths that I have personally debunked.
MYTH #1 - BUSHING DIES ARE ONLY SUITABLE FOR BRASS WITH TURNED NECKS, AND YOU MUST USE AN EXPANDER BALL. When I decided to get into LR rifle shooting (1,000 yards F Class), I bought the Redding Competition Die Sets for 3 cartridges: .308, .30-06, and 6.5x55. I have tactical/match rifles chambered for these cartridges, as well as a FAL and M1 Garand. The first thing I did was remove the decapping pin and expander ball. Decapping of my brass is done with a Universal Decapping Die. When you have the capability to “tune” your sizing die to give you varying amounts of neck tension by using various size bushings, it simply makes no sense to then drag an expander ball thru your nice straight necks. Using this method, I have developed loads with neck tension ranging from .001” for F Class loads, to .004” for FAL and Garand loads. Inserting a bullet into the neck performs the same function as a mandrel or expander ball; whatever minute internal neck dimension variations there are due to variations in neck wall thickness, are moved to the outside of the neck by the bullet. I have seen many posts stating that you will have varying amounts of neck tension by doing this, but in my shooting at 1,000 yards, I have not seen any of the vertical dispersion that would surely be seen if this was the case.
MYTH #2 – THE .308 IS INHERENTLY MORE ACCURATE THAN THE .30-06. I am well aware of the article by Bart Bobbit that was posted over 11 years ago, and makes comparisons between the two cartridges that go back 50+ years. In any comparison of the two cartridges as they were loaded in that time period for the M14 and M1, I am in complete agreement that in perhaps 9 times out of 10, in rifles of comparable accuracy, the .308 will exhibit slightly greater accuracy. However, once you remove the criteria that the .30-06 cartridge must be loaded down so as to be suitable for firing in a M1 Garand (bullet less than 180 grains and a powder no slower than 4064), you can essentially remake the .30-06 into a cartridge that is much better suited to it’s case capacity. About 7 years ago, myself and another guy on Sniper’s Hide started doing load development with the 190 grain Sierra MatchKing bullet and 60.0+ grains of RL22 powder. We quickly found that it was possible to develop highly accurate LR loads at slightly above 2900fps, and still remain within the 60k psi limits of the cartridge. Oh, and just so you don’t think I have nothing to compare it to, I have a highly accurate .308 as well. But, thru my personal experience, I have come to believe that a rifle’s accuracy is more a factor of the quality of the barrel and smithing that went into the rifle as well as the quality/suitability of the ammo, and not in any mythical “inherent” accuracy that many posters like to attributed to the cartridge itself.
MYTH #3 – THE .308 OPERATES AT A MUCH HIGHER PRESSURE THAN 7.62X51, AND THEY ARE DIFFERENT AND SHOULD NOT BE INTERCHANGED.
While there are some articles that are now debunking this, the fact is that guys still continue to post this erroneous info. Now, understand, I am not talking about using just any old .308 ammo in a rifle with port pressure constraints such as the M1 or M14. What I am talking about is the maximum pressure of the two cartridges as determined by the U.S. government (7.62x51) and SAAMI (.308). And therein lies the problem and confusion. While the government lists the 7.62x51 pressure specs as 50,000 psi, it was actually determined using the copper crusher method, and is in fact 50,000 CUP. The government doesn’t subscribe to SAAMI standards, and obviously feels they can call the unit of pressure psi if they want to. The .30-06 is an example of a military cartridge for which we have pressure specs in both CUP and psi: 50,000 CUP and 60,000 psi. If the 7.62x51 was truly 50,000 psi, it would be a cartridge with power similar to the .30-40 Krag, rather than being nearly the ballistic twin of the .30-06. Sometimes you just have to use logic, instead of just accepting information that is obviously flawed.
In summary, while the Internet is a great place to obtain information and data, it does not eliminate the need for casting a critical eye on what is being posted as fact, and sometimes having to determine for yourself thru experimentation and load development, if the “Internet fact” is indeed fact, or is just another of those urban legends that gain a life of their own thru repeated references to it. Just MHO.
Don
MYTH #1 - BUSHING DIES ARE ONLY SUITABLE FOR BRASS WITH TURNED NECKS, AND YOU MUST USE AN EXPANDER BALL. When I decided to get into LR rifle shooting (1,000 yards F Class), I bought the Redding Competition Die Sets for 3 cartridges: .308, .30-06, and 6.5x55. I have tactical/match rifles chambered for these cartridges, as well as a FAL and M1 Garand. The first thing I did was remove the decapping pin and expander ball. Decapping of my brass is done with a Universal Decapping Die. When you have the capability to “tune” your sizing die to give you varying amounts of neck tension by using various size bushings, it simply makes no sense to then drag an expander ball thru your nice straight necks. Using this method, I have developed loads with neck tension ranging from .001” for F Class loads, to .004” for FAL and Garand loads. Inserting a bullet into the neck performs the same function as a mandrel or expander ball; whatever minute internal neck dimension variations there are due to variations in neck wall thickness, are moved to the outside of the neck by the bullet. I have seen many posts stating that you will have varying amounts of neck tension by doing this, but in my shooting at 1,000 yards, I have not seen any of the vertical dispersion that would surely be seen if this was the case.
MYTH #2 – THE .308 IS INHERENTLY MORE ACCURATE THAN THE .30-06. I am well aware of the article by Bart Bobbit that was posted over 11 years ago, and makes comparisons between the two cartridges that go back 50+ years. In any comparison of the two cartridges as they were loaded in that time period for the M14 and M1, I am in complete agreement that in perhaps 9 times out of 10, in rifles of comparable accuracy, the .308 will exhibit slightly greater accuracy. However, once you remove the criteria that the .30-06 cartridge must be loaded down so as to be suitable for firing in a M1 Garand (bullet less than 180 grains and a powder no slower than 4064), you can essentially remake the .30-06 into a cartridge that is much better suited to it’s case capacity. About 7 years ago, myself and another guy on Sniper’s Hide started doing load development with the 190 grain Sierra MatchKing bullet and 60.0+ grains of RL22 powder. We quickly found that it was possible to develop highly accurate LR loads at slightly above 2900fps, and still remain within the 60k psi limits of the cartridge. Oh, and just so you don’t think I have nothing to compare it to, I have a highly accurate .308 as well. But, thru my personal experience, I have come to believe that a rifle’s accuracy is more a factor of the quality of the barrel and smithing that went into the rifle as well as the quality/suitability of the ammo, and not in any mythical “inherent” accuracy that many posters like to attributed to the cartridge itself.
MYTH #3 – THE .308 OPERATES AT A MUCH HIGHER PRESSURE THAN 7.62X51, AND THEY ARE DIFFERENT AND SHOULD NOT BE INTERCHANGED.
While there are some articles that are now debunking this, the fact is that guys still continue to post this erroneous info. Now, understand, I am not talking about using just any old .308 ammo in a rifle with port pressure constraints such as the M1 or M14. What I am talking about is the maximum pressure of the two cartridges as determined by the U.S. government (7.62x51) and SAAMI (.308). And therein lies the problem and confusion. While the government lists the 7.62x51 pressure specs as 50,000 psi, it was actually determined using the copper crusher method, and is in fact 50,000 CUP. The government doesn’t subscribe to SAAMI standards, and obviously feels they can call the unit of pressure psi if they want to. The .30-06 is an example of a military cartridge for which we have pressure specs in both CUP and psi: 50,000 CUP and 60,000 psi. If the 7.62x51 was truly 50,000 psi, it would be a cartridge with power similar to the .30-40 Krag, rather than being nearly the ballistic twin of the .30-06. Sometimes you just have to use logic, instead of just accepting information that is obviously flawed.
In summary, while the Internet is a great place to obtain information and data, it does not eliminate the need for casting a critical eye on what is being posted as fact, and sometimes having to determine for yourself thru experimentation and load development, if the “Internet fact” is indeed fact, or is just another of those urban legends that gain a life of their own thru repeated references to it. Just MHO.
Don
