i’m attracted to guns. i am focused on cartridges. i admire the Winchester “more suitable Mauser” motion. i am enamored with the 7mm-08.
That’s likely why all through a prairie dog hunt with Sierra this summer season, i assumed of the historical past and plight of the .308 175gr Sierra healthy King bullet with nostalgia and depression.
1993 was a tough year. The Brady bill turned into signed into law, Islamic fundamentalist terrorists first bombed the area exchange center, the ATF murdered a bunch of americans in Waco, and Beanie little ones had been universal.
On the plus aspect, this gawky youngster from the tiny city of Dripping Springs, Texas all started school the place the feminine to male ratio turned into essentially four:1 and the USA Marine Corps adopted the M118 special Ball long range cartridge for their 7.62×51 NATO chambered rifles. The M118LR changed into born.
Sierra constructed the 175gr boat tail hole factor (BTHP) round for the cartridge, named the Sierra healthy King (SMK). despite the fact the propellant and primer has modified for the M118LR over the a long time, the bullet didn’t. The efficiency of that bullet, along with the richly deserved acceptance of the USMC Scout/Scout-Sniper and marksmanship teams ensured the round became synonymous will lengthy-range taking pictures.
because then, that 175gr SMK has been around the globe, punching holes in paper and Pashtuns alike. It’s been chambered in bolt weapons and semi-cars. Its efficiency and relatively comparatively cheap have made it the go-to bullet for civilian and armed forces shooters alike for many years now.
extra perfect bullets than the 175gr SMK exist. There are rounds with greater polished jackets, extra constant meplats, and more constant dimensions (at a value).
There are additionally somewhat a few bullets of the identical caliber and of similar weight with greater ballistic coefficients. Take, for example, the Nosler 175gr RDF, with a G7 BC of .270, the Berger 175 gr fit MTLR with a G7 of .264, or the Hornady 178 gr ELD-M with its very slick .275.
The big abilities there is that the larger BC makes it possible for the shooter more error when judging wind at lengthy levels. And every person misjudges wind. a few of us simply plenty, a great deal more than others.
The downside is that those bullets regularly require greater twist rates or have a slender Cartridge universal length latitude to fire invariably. The SMK doesn’t. A 1:11″ or 1:12″ twist rate will stabilize the SMK simply first-class, which is why so many armed forces rifles proceed to be chambered with these twist fees.
A 1:12 twist rate existed lengthy before the SMK bullet or the M118LR cartridge. We see it on US semi-computerized battle rifles going all of the manner back to the Vietnam war. returned then they shot a 173 gr FMJBT. I think about that twist rate changed into regarded when making the SMK, after which the ubiquitous use of the M118LR and the SMK that sits atop it persevered to force the 1:eleven to 1:12 fees, however here’s merely speculation.
When FN launched their SCAR 20S, they put in the same 1:12 twist cost that existed on their previous defense force-best version Mk20 SSR. That fee turned into chosen since the bullet the militia desired to shoot, the a hundred seventy five gr SMK, stabilized just best at that expense. Civilians, who in the past demanded a rifle identical to the one the military used then wanted to shoot heavier bullets or rounds with a more robust BC than the SMK, so the newer models of the 20S recreation the sooner 1:10 twist expense.
Out of curiosity, I grabbed a container of 100 bullets and obtained to checking out them.
A friend of mine has a shop with a dial indicator used to measure concentricity. I measured a number of bullets, however received the equal result for all of them. The influence turned into all zeros, which means that the three zeros correct of the decimal place that I could measure weren’t specific enough to give me an excellent reading.
using a Lyman digital powder scale, I weighed every of the bullets…all 100 of them. The lightest circular measured 174.6. grains. The heaviest circular measured 174.9 grains…and just about all of them weighed 174.9 grains. there were so many 174.9 rounds that, when measured to the closest tenth of a grain, each the median and the mean have been 174.9 grains.
one of the vital very great things about 175 gr SMK is that it has been around for ages and a huge quantity of facts is effectively obtainable 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. however that’s wrong. in reality, my bullet is simply going 2,437 fps from that Remington 5-R‘s barrel (measured on the time of testing), and all of my rounds are landing simply a bit bit excessive, on the grounds that this gun and ammunition’s 1/2 MOA precision means.
Sierra’s posted information, my circular goes a whole lot slower than the 2,800 fps that .505 BC is based mostly off of. the use of the appropriate .496 and .495 numbers, I arrive at 236″ of drop, which is where my bullet is truly landing.
If i needed any further records concerning the SMK, including applications, efficiency, truly anything at all, I could name the Sierra Tech line at 800-223-8799 five days every week, 7am-7pm. That’s a true element. you could name their tech line and talk to an exact person who basically is aware of in regards to the bullets.
I had no intent to achieve this other than to simply determine that it has some cost, and yeah, there are really people who decide on up the cellphone and can answer questions. Sierra isn’t the only bullet enterprise to have technical/product assist. Most do. however few have technical help mobile traces obtainable and staffed so neatly. And none that i know of with such a huge and multiple construction line.
There are some smaller agencies that deliver this form of consumer carrier, like Berger Bullets. When that enterprise first all started gaining traction, my emails had been instantly and comprehensively answered by using Brian Litz. back earlier than ballistic functions blanketed a “Litz” category for BC, a few 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. Two of these is the .243 G7 BC of the 175gr SMK. That’s right, no remember who you are and what bullets you are making, you’ve spent some time on the Sierra in shape King.
All that, and placing so so lots of them via metallic tubes, is why i’m so nostalgic for the a hundred seventy five gr SMK. My melancholy comes from the realization that the a hundred seventy five gr SMK’s reign is near its end.
The 6.5 Creedmoor already been adopted with the aid of SOCOM, however FN and others are offering a few of their previosly 7.62 NATO only desktop weapons in the 6.5 Creedmoor as well.
That’s just an intermediate measure for some gadgets whereas the true exchange is taking vicinity. the new 6.8mm round and its father or mother super space cartridge are moving ahead in the course of the DoD methods and are destined to be the armed forces’s new go-to for all things near(ish) and far(ish).
eventually, civilians will comply with go well with, and the circular once used as the general for lengthy-latitude armed forces shooting will go the manner of black powder and steel butt plates.
Which means I’ll nevertheless be shooting it, right subsequent to whatever thing new X.fancymm intergalactic telescopic polymer cartridge was just released to the internal planets.
“collect circular, youngsters, and let grandpa let you know about slow, fat bullets, and the men who cherished ’em.”