i’m drawn to guns. i’m serious about cartridges. i like the Winchester “superior Mauser” action. i am enamored with the 7mm-08.
That’s probably why, right through a prairie dog hunt with Sierra this summer, i believed of the historical past and plight of the .308 175gr Sierra match King bullet with nostalgia and depression.
1993 become a rough 12 months. The Brady bill become signed into law, Islamic fundamentalist terrorists first bombed the world alternate core, the ATF murdered a bunch of americans in Waco, and Beanie little ones were common.
On the plus facet, this gawky kid from the tiny city of Dripping Springs, Texas begun college where the female to male ratio was just about 4:1 and the U.S. Marine Corp adopted the M118 special Ball lengthy range cartridge for his or her 7.sixty two×fifty one NATO chambered rifles. The M118LR changed into born.
Sierra built the new boat tail hole point (BTHP) circular for the cartridge, and named it the 175gr Sierra suit King (SMK). although the propellant and primer has changed for the M118LR over the a long time, the bullet didn’t. The performance of that bullet, along with the richly deserved popularity of the USMC Scout/Scout-Sniper and marksmanship teams ensured the circular became synonymous with lengthy-range capturing.
considering the fact that then, that 175gr SMK has been all over the world, punching holes in paper and Pashtuns alike. It’s been chambered in bolt weapons and semi-cars. Its performance and comparatively reasonably-priced have made it the go-to bullet for a lot of civilian and military shooters alike for decades now.
more perfect bullets than the 175gr SMK exist. There are rounds with extra polished jackets, greater constant meplats, and extra consistent dimensions (at a value).
There are additionally somewhat a couple of bullets of the equal caliber and of an identical weight with bigger ballistic coefficients. Take, for instance, the Nosler 175gr RDF, with a G7 BC of .270, the Berger a hundred seventy five gr fit MTLR with a G7 of .264, or the Hornady 178 gr ELD-M with its very slick .275.
The large knowledge there’s that the greater BC makes it possible for the shooter extra error when judging wind at long degrees. And all and sundry misjudges wind. some of us just a lot, tons greater than others.
The draw back is that those bullets regularly require bigger twist costs or have a really selected depth from the rifling lands (or require contact with them) to function always. The SMK doesn’t. A 1:11″ or 1:12″ twist price will stabilize the SMK simply quality, which is likely why so many armed forces rifles proceed to be chambered with these twist fees.
A 1:12 twist rate existed lengthy before the .308 caliber SMK bullet or the M118LR cartridge. We see it on US semi-automatic battle rifles going all of the approach lower back to the Vietnam war. returned then they shot a 173 gr FMJBT. I think about that twist rate became considered when making the 175gr SMK, and then the ever present use of the M118LR and the bullet that sits atop it persevered to power the 1:eleven to 1:12 prices, but here is only hypothesis.
When FN released their SCAR 20S, they put in the equal 1:12 twist cost that existed on their old armed forces-only version Mk20 SSR. That twist expense was chosen since the bullet the armed forces desired to shoot, the a hundred seventy five gr SMK, stabilized just quality at that price. Civilians, who prior to now demanded a rifle just like the one the military used then desired to shoot heavier bullets or rounds with a more robust BC than the 175gr SMK, so the more moderen types of the 20S activity the faster 1:10 twist expense.
Out of curiosity, I grabbed a field of 100 bullets and bought to trying out them.
A chum of mine has a store with a dial indicator used to measure concentricity. I measured a few bullets, however obtained the same outcome for all of them. The effect was all zeros, meaning that the three zeros right of the decimal place that I may measure weren’t genuine adequate to give me a great analyzing.
the use of a Lyman digital powder scale, I weighed each of the bullets…all 100 of them. The lightest round measured 174.6. grains. The heaviest circular measured 174.9 grains…and almost all of them weighed 174.9 grains. there have been so many 174.9 rounds that, when measured to the nearest tenth of a grain, both the median and the suggest were 174.9 grains.
some of the very excellent things about 175 gr SMK is that it has been around for a long time and a huge volume of facts is without problems accessible for it. If I plugged a G1 BC of .505 into my ballistic calculator, and shot out to 800 yards, I’d get an estimated 229″ of drop. but that’s wrong. definitely, my bullet is barely going 2,437 fps from that Remington 5-R‘s barrel (measured at the time of trying out), and all of my rounds are landing just a bit bit off, considering this gun and ammunition’s 1/2 MOA precision potential.
taking a look at Sierra’s posted data, my round is going a whole lot slower than the two,800 fps that .505 BC is based mostly off of. the usage of the relevant .496 and .495 numbers, I arrive at 236″ of drop, which is, oddly adequate, the place my bullet is basically touchdown.
If i needed any additional information about the SMK, including purposes, efficiency, truly the rest in any respect, I may call the Sierra Tech line at 800-223-8799 5 days every week, 7am-7pm. That’s a true aspect. you could name their tech line and speak to an actual person who in fact is aware of in regards to the bullets.
I had no rationale to accomplish that apart from to simply assess that it has some value, and yeah, there are definitely individuals who pick up the cell and may reply questions. Sierra isn’t the simplest bullet business to have technical/product help. Most do, however by email or online kind. Few have technical help mobilephone lines accessible and staffed so well. And none that i do know of with such a large and dissimilar construction line.
There are some smaller groups that give this kind of customer provider, like Berger Bullets. When that company first began gaining traction, my emails had been directly and comprehensively answered through Brian Litz. returned before ballistic applications included a “Litz” class for BC, some of my computations had “Per Litz” listed next to them, as a result of these are the values he blanketed in his emails to me. a type of is the .243 G7 BC of the 175gr SMK. That’s right, no matter who you’re and what bullets you are making, you’ve spent some time on the 175gr Sierra in shape King.
All that, and inserting so so lots of them through steel tubes, is why i’m so nostalgic for the a hundred seventy five gr SMK. My depression comes from the attention that the 175 gr SMK’s reign is near its end.
The 6.5 Creedmoor already been adopted through SOCOM, but FN and others are providing a few of their previosly 7.sixty two NATO handiest desktop weapons in the 6.5 Creedmoor as well.
That’s just an intermediate measure for some instruments while the precise change is taking location. the brand new 6.8mm circular and its mum or dad super area cartridge are relocating ahead during the DoD programs and are destined to be the defense force’s new go-to for all things near(ish) and far(ish).
eventually, civilians will comply with swimsuit, and the circular as soon as used as the ordinary for lengthy-latitude military taking pictures will go the way of black powder and steel butt plates.
Which capability I’ll nevertheless be shooting it, appropriate next to whatever new X.fancymm intergalactic telescopic polymer cartridge turned into simply launched to the internal planets.
“accumulate round, youngsters, and let grandpa let you know about gradual, fat bullets, and the men who loved ’em.”