Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Rifles, Reloading, Optics, Equipment
Reloading
Federal 308 Gold Medal Match Powder?
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Bart B" data-source="post: 738195" data-attributes="member: 5302"><p>Diamondback, here's some "food" for thought:</p><p></p><p>First, here's some excellent info on accurate ammo for the .308 Win. as well as 7.62 NATO ammo:</p><p></p><p><a href="http://riflemansjournal.blogspot.com/2012/02/cartridges-762-nato-long-range-match.html" target="_blank">The Rifleman's Journal: Cartridges: 7.62 NATO Long Range Match Cartridges - Part 1</a></p><p></p><p><a href="http://riflemansjournal.blogspot.com/2012/02/cartridges-762-nato-long-range-match_04.html" target="_blank">The Rifleman's Journal: Cartridges: 7.62 NATO Long Range Match Cartridges - Part 2</a></p><p></p><p><a href="http://riflemansjournal.blogspot.com/2010/04/history-us-national-match-ammunition.html" target="_blank">The Rifleman's Journal: History: US National Match Ammunition - Ray Meketa</a></p><p></p><p><a href="http://riflemansjournal.blogspot.com/2009/07/history-national-match-ammunition.html" target="_blank">The Rifleman's Journal: History: National Match Ammunition</a></p><p></p><p>Note the section in the National Match Ammo sites on M852 ammo. Having shot a few thousand rounds of M852 and a few more thousand rounds of its predecessor, M118, all in serious competition, I can attest with certainty that over all, the best lots of M118 were more accurate than those of M852. Others on military rifle teams I shot with tend to agree. Nothing with 168's compared to the M118 ammo produced in the mid 1960's.</p><p></p><p>Second, the specs picture has some errors in it:</p><p></p><p>The M852 round length of 2.83" was set as that's the longest they could be for reliable feeding from M14 magazines; it had nothing to do with accuracy. Besides, as a barrel's leade grows in length as it erodes away, bullets need to be seated longer every few hundred rounds to maintain the same jump distance to the rifling.</p><p></p><p>The arsenal set peak pressure specs for M852 ammo to the same level as M118; 50,000 cup (copper units of pressure as measured by crusher gauges). That equates to about 59,000 psi ()pounds per square inch as measured by piezo or strain gauges). Barrel length has no effect on peak pressure; just velocity. Those velocity and pressure numbers at the bottom of the graphics are way off from reality for some reason; 2650 fps with either 49,142 psi or 52,850 psi equate to pressures measured by copper crusher gauges down in the 44,000 range. Do you understand the difference between cup and psi numbers and why they are so often mixed up, especially in printed military specs?</p><p></p><p>Arsenals measured muzzle velocity for small arms at 78 feet; 26 yards. Why has never been well understood or known. So while a bullet may be traveling that fast 26 yards down range, it's around 50 to 60 fps faster at the muzzle.</p><p></p><p>Muzzle velocity is effected by four physical dimensions of the barrel; chamber leade dimensions, groove diameter, bore diameter and the bore's cross sectional area determined by the width of the lands and grooves. For example, SAAMI specs for the .308 Win. has bore area at .0736 square inches, 47.483 square millimeters.</p><p></p><p>Charge weights Lake City uses are set so muzzle velocity is in a +/- 30 fps range so it'll have the same trajectory for all lots of M852 (M118, too) making sight settings on M1 and M14 rifles repeatable. The charge weight also has to have peak pressure within specs about 50,000 cup. And it has to produce accuracy at 600 yards from test barrels getting no more 3.5 inch mean radius; that's about 10 inches. 1.67 MOA. Ammo I've weighed charges from has had a 2 grain or more spread.</p><p></p><p>Regarding why you posted the the M852 168gr specs, they don't match all of the actual history and preferences of competitive shooters. Military and civilian rifle competitors winning the matches and setting the records preferred heavier bullets in the 7.62 NATO for ranges 600 yards and further when allowed by match rules. Sierra's 180's and 190's were preferred by folks shooting M1 or M14 match grade rifles; they shot more accurate than anything produced by the arsenals (check the above links on match ammo). Sierra's 190's and 200's as well as Lapua's 185's were preferred by those shooting as well with bolt action match rifles. The military got tired of their M852 ammo producing poor accuracy from bullets tumbling starting at 600 yards in somewhat worn out barrels in cooler weather and at most anytime at 800 yards and further; the 168's shape was not optimal to keep the bullet supersonic through 1000 yards. Sierra's 175-gr. HPMK eventually replaced it.</p><p></p><p>The best accuracy both M118 and M852 ever had was about 6 inches at 600 yards in the best of their National Match lots. Commercial .308 Win. match ammo (Federal?) easily shot about 4 inches at 600 from the best M1 and M14 match grade service rifles; no arsenal ammo ever came close. M852 ammo has never been the "gold standard" of .308/7.62 ammo as Federal's and Black Hills' match ammo has out performed M852 for decades. If M852 was really the standard, the military teams would never have bought millions of rounds of Federal or Remington .308 Win. commercial match ammo to use when it was allowed.</p></blockquote><p></p>
[QUOTE="Bart B, post: 738195, member: 5302"] Diamondback, here's some "food" for thought: First, here's some excellent info on accurate ammo for the .308 Win. as well as 7.62 NATO ammo: [url=http://riflemansjournal.blogspot.com/2012/02/cartridges-762-nato-long-range-match.html]The Rifleman's Journal: Cartridges: 7.62 NATO Long Range Match Cartridges - Part 1[/url] [url=http://riflemansjournal.blogspot.com/2012/02/cartridges-762-nato-long-range-match_04.html]The Rifleman's Journal: Cartridges: 7.62 NATO Long Range Match Cartridges - Part 2[/url] [url=http://riflemansjournal.blogspot.com/2010/04/history-us-national-match-ammunition.html]The Rifleman's Journal: History: US National Match Ammunition - Ray Meketa[/url] [url=http://riflemansjournal.blogspot.com/2009/07/history-national-match-ammunition.html]The Rifleman's Journal: History: National Match Ammunition[/url] Note the section in the National Match Ammo sites on M852 ammo. Having shot a few thousand rounds of M852 and a few more thousand rounds of its predecessor, M118, all in serious competition, I can attest with certainty that over all, the best lots of M118 were more accurate than those of M852. Others on military rifle teams I shot with tend to agree. Nothing with 168's compared to the M118 ammo produced in the mid 1960's. Second, the specs picture has some errors in it: The M852 round length of 2.83" was set as that's the longest they could be for reliable feeding from M14 magazines; it had nothing to do with accuracy. Besides, as a barrel's leade grows in length as it erodes away, bullets need to be seated longer every few hundred rounds to maintain the same jump distance to the rifling. The arsenal set peak pressure specs for M852 ammo to the same level as M118; 50,000 cup (copper units of pressure as measured by crusher gauges). That equates to about 59,000 psi ()pounds per square inch as measured by piezo or strain gauges). Barrel length has no effect on peak pressure; just velocity. Those velocity and pressure numbers at the bottom of the graphics are way off from reality for some reason; 2650 fps with either 49,142 psi or 52,850 psi equate to pressures measured by copper crusher gauges down in the 44,000 range. Do you understand the difference between cup and psi numbers and why they are so often mixed up, especially in printed military specs? Arsenals measured muzzle velocity for small arms at 78 feet; 26 yards. Why has never been well understood or known. So while a bullet may be traveling that fast 26 yards down range, it's around 50 to 60 fps faster at the muzzle. Muzzle velocity is effected by four physical dimensions of the barrel; chamber leade dimensions, groove diameter, bore diameter and the bore's cross sectional area determined by the width of the lands and grooves. For example, SAAMI specs for the .308 Win. has bore area at .0736 square inches, 47.483 square millimeters. Charge weights Lake City uses are set so muzzle velocity is in a +/- 30 fps range so it'll have the same trajectory for all lots of M852 (M118, too) making sight settings on M1 and M14 rifles repeatable. The charge weight also has to have peak pressure within specs about 50,000 cup. And it has to produce accuracy at 600 yards from test barrels getting no more 3.5 inch mean radius; that's about 10 inches. 1.67 MOA. Ammo I've weighed charges from has had a 2 grain or more spread. Regarding why you posted the the M852 168gr specs, they don't match all of the actual history and preferences of competitive shooters. Military and civilian rifle competitors winning the matches and setting the records preferred heavier bullets in the 7.62 NATO for ranges 600 yards and further when allowed by match rules. Sierra's 180's and 190's were preferred by folks shooting M1 or M14 match grade rifles; they shot more accurate than anything produced by the arsenals (check the above links on match ammo). Sierra's 190's and 200's as well as Lapua's 185's were preferred by those shooting as well with bolt action match rifles. The military got tired of their M852 ammo producing poor accuracy from bullets tumbling starting at 600 yards in somewhat worn out barrels in cooler weather and at most anytime at 800 yards and further; the 168's shape was not optimal to keep the bullet supersonic through 1000 yards. Sierra's 175-gr. HPMK eventually replaced it. The best accuracy both M118 and M852 ever had was about 6 inches at 600 yards in the best of their National Match lots. Commercial .308 Win. match ammo (Federal?) easily shot about 4 inches at 600 from the best M1 and M14 match grade service rifles; no arsenal ammo ever came close. M852 ammo has never been the "gold standard" of .308/7.62 ammo as Federal's and Black Hills' match ammo has out performed M852 for decades. If M852 was really the standard, the military teams would never have bought millions of rounds of Federal or Remington .308 Win. commercial match ammo to use when it was allowed. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Reloading
Federal 308 Gold Medal Match Powder?
Top