Just curious what my max range would be for a 168 gr SMK out of a 20" .308 barrel. Just ballpark, doesn't have to be extremely specific. I keep reading that 175's do much better at distance, but I am heavily invested in 168's at the moment. I'm at 1000 feet. I know temp and humidity will play a factor too, but I'm just looking for general info. 700 yards before they start losing stability? 800 yards? 900 yards?
- Thread starter MORIfleman
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for hunting or just trying to hit steel?
i shot 168s out of a 20" for a year and took it to 1,000 many times, even once during a match. the wind bullied me hard though.
i shot 168s out of a 20" for a year and took it to 1,000 many times, even once during a match. the wind bullied me hard though.
What velocity? I used to shoot a 20" 308 with 168 moving at 2600 (slow). I always considered it 600-700 and in. Not the best ballistically, especially going that slow.
Strictly for fun on steel, no hunting. I would be in the 2500-2600 ballpark too.
I never shot mine past 600 much. I tried the 175s, but my barrel didn't like them.
I recently shot a match using FGMM 168s out to 1K. They were moving about 2750fps out of my 26" barrel, at about 90*/1700'/50% humidity, and they were stable and repeatable at that distance. Granted, they have the flight path of a grand piano past about 600y and a switching 8-12mph wind pushed them around to the tune of 1.8-2.2mil, but it was doable.
I don't know if Sierra has changed those 168's since I tried them 10 years ago but I had them becoming unstable to the point of hitting the dirt in front of the target during a 1,000 yard BR match. A couple of other shooters the had read somewhere that the 168's were known to do that. I went back to the 175's and never looked back. Since the rifle would shoot 150's and 175's OK to 1K, I'm reasonably sure it wasn't a rate of twist issue. I also know that I had plenty of velocity behind them. The guys that had read about the problem said the article recommended 600yd max for the 168SMK's. It could be that it is very picky about rate of twist.
I get the 168 ELD at 2800 out of a 22" at sea level. The numbers aren't bad and it was easy to load for.
To be clear, it's not a problem with the bullet weight but the angle of the boat tail specific to the Sierra Matchking and it's clone, the Nosler Custom Competition. Some say using faster twist barrel alleviates the problem, hence that Todd guy and his 1:8 twist barrel recommendation... switching to berger or hornady eld's and the problem goes away in 10 and 12 twist barrels.
When I first started shooting out to a grand 168 smk's were what I had, along with a 1:12 twist barrel on my 20" factory R700 tactical and 21.75" 1:11.27 rock creek custom. Like you, I'm at 1000' ASL. Depending on the air density, some days they would make it to the 1000 yard gong nose first, other days 900 was a struggle to not have a few oblong impacts. The higher the DA, the better they would group out there. The lower temperature/barometric pressure days I'd just practice inside 800. Which for a 308 is where it thrives away.
When I first started shooting out to a grand 168 smk's were what I had, along with a 1:12 twist barrel on my 20" factory R700 tactical and 21.75" 1:11.27 rock creek custom. Like you, I'm at 1000' ASL. Depending on the air density, some days they would make it to the 1000 yard gong nose first, other days 900 was a struggle to not have a few oblong impacts. The higher the DA, the better they would group out there. The lower temperature/barometric pressure days I'd just practice inside 800. Which for a 308 is where it thrives away.
In my 16” 308 with Saker 7.62 suppressor I get 2,591 FPS at 950 ASL. I would like to get higher velocity, but this load shoots into the 0.2’s if I do my part with a SD of 4 and ES of 10.4 FPS. I get good consistent results out to 900 but it seams to fall apart by 1,000. Ballistic app shows it going subsonic at 925, so I’m guessing that’s why. I’m sure you could get higher velocity with the 20” but I’m just not sure how much that’s going to help with that projectile. I’m not sure if it’s been re-designed, but Sierra even admitted that the 168 is optimized for 600 and in. But, like I said, I have had good luck out to 900. Are their better choices? Sure, but if your “heavily invested” run what you have and learn all you can with them. Then when you need more projos, switch to something better. Take a look at a ballistic app and run the numbers. I also tried the 178 in my 16” and I’m only able to get 2,500 FPS with the accuracy I’m after. Funny thing is with the 178 I’m still going subsonic at 925 and both the 168 and 175 have 3 MIL’s of wind at 925 so in MY rifle at MY velocities, they are ballisticslly identical for punching paper. It’s not a whole lot different with a longer barrel though. In my 24” barrel the 178 gets 2,788 FPS. That sounds great and all being 288 fps faster than the 16”, but in practice it only carries me 150 yard further before going subsonic. HOWEVER, that 178 handles the transonic and subsonic much better and still allows me to make accurate hits into the subsonic ranges. So study up on your projectiles before switching. In the mean time, expect 900 to be max with your most consistent to be 750 or less.
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Deleted member 10043
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Quit throwing up the Litz shit from his first book and stupidly taking credit for it. We got people who know nothing about it ignorantly shooting out to 1K with acceptable stability for a 308. I called bullshit on that when it when it first came out. I even asked Sierra about it and their response was if they thought something was wrong with their 168 they would have fixed it long before Litz started masturbating as a kid. It was nothing more than competition propaganda. Litz works for Berger first and foremost. Without Berger he has no "state of the art laboratory" and will always have that conflict of interest dark cloud over his head. I don't know what happened but he has pretty much stopped bullshit like this but for Sierra the damage is done and is a real consequence for them. With that out of the way their 168 was designed for 300 meter precision competition to begin with. If people want to take it out to 1K than more power to them.
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But they did fix it and brought us the 175.
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When did Sierra start offering the 175?
I don't recall, but there was a thread a few years back from a crusty old high power shooter that explained the time line well. The story went... Back when everyone was still using M1a's and struggling with the 168's. They turned to the 180mk until the BT redesign copied the 168 BT and the 180 smk went to crap. The 175 came around and had the shallower angle of the 173fmjbt &190mk which proved successful.
Maybe it's all a story, IDK. But it made sense to me and followed my own struggles I was having back in 2010 went I found a 1000 yard range to join. Litz just gave us a scientific fluid dynamics explanation of what was being seen.
Maybe it's all a story, IDK. But it made sense to me and followed my own struggles I was having back in 2010 went I found a 1000 yard range to join. Litz just gave us a scientific fluid dynamics explanation of what was being seen.
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Deleted member 10043
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The 175 was originally developed by Sierra as a military sniper bullet in 1995 for better accuracy at 1000 yards at supersonic. The 168 was developed in 1959 for medium range competition. They are two completely different animals.
Not sure who this was directed at, but it was immediately after my post. If it’s at me, I’m not repeating what anyone else said, that I’m aware of. I’m only sharing my own personal experiences. I don’t own anything Litz, books or otherwise. Like I said in my post, these are MY results in MY rifles. Others may be different. All I know is that I’m fairly consistent at the closer ranges out to about 900 or so but by the time I’m at 1000 I just can’t do it with any real consistency. Wether that’s the trigger puller, the wind, or what, I couldn’t tell you. I’m just no where near as consistent as I want to be.
If I ruffled any feathers with sharing what I’ve experienced, then sorry for sharing.
ETA, if it’s in reference to what I said a bout the bullet being made for 600 and in, I have heard that for years from a number of benchrest shooters and have read it a few times on the internets, so it’s gotta be true right? Lol. If I’m wrong, so be it. I was really hoping to trust those who repeated it to me.
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Deleted member 10043
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If you didn't read and then paraphrase Litz than it not about you, right?
Anyway, an example of debunking Litz on the 168 SMK. I don't think those hits and misses are the result of an unstable bullet. I'm going to go out on a limb here and note the serape for a shooting mat along with the Mojave desert backdrop as authentic. The guy on the bike probably thinks the 168 is serous enough, lol.
Anyway, an example of debunking Litz on the 168 SMK. I don't think those hits and misses are the result of an unstable bullet. I'm going to go out on a limb here and note the serape for a shooting mat along with the Mojave desert backdrop as authentic. The guy on the bike probably thinks the 168 is serous enough, lol.
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