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Old March 27, 2009, 07:09 AM   #1
Bart B.
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Busted Myth: Don't Shoot Sierra .308 168's at 1000 Yards

Sierra Bullets came out with their 30 caliber 168-gr. International hollow point boattailed match bullet in 1958 designed for 300 metre free rifle matches. It soon became popular for high power matches in both bolt guns and the M1 Garand for use at 200 through 600 yards. It did well at 1000 yard matches, too, when leaving the barrel at 2800 fps which it did with maximum loads in the .30-06 in proper dimensioned (tight groove diameter; .3078 or smaller) barrels at least 24 inches long.

Along came the M14 with its 22 inch barrel and in 1963, its cartridge was first allowed at the US National Matches. The 172-gr. .3086-in. diameter military match bullet used in M118 ammo did well in the M14 as well as the 7.62MM NATO Garands. A lot of the barrels on these rifles were a bit over sized (.3082 or more) compared to groove diameters needed for best accuracy, but that "fat" military match bullet caused enough chamber pressure to push it out fast enough that it did well in the 1000 yard matches.

When Lake City Arsenal began using Sierra's 168 in their new M852 match ammo, things still went good, often better, when tight. But only through 600 yards. Some M14, M1A commercial and M1 rifles shooting it had barrels enough oversize that the bullet didn't leave fast enough. Those 168's would go transonic at 800 t0 900 yards and become unstable enough to change direction. Elongated holes on paper showed they had done so.

Meanwhile, folks shooting these bullets fast enough through tight barrels had no problem. But that wasn't good enough for most folks and pressure on Lake City Arsenal's engineers convinced them to make a change. They came out with the M118LR round using Sierra's 175-gr. HPMK bullet. These would stay supersonic through 1000 yards...even in loose barrels didn't shoot them very fast.

So, yes, Sierra 168's can be used in a .308 Win. for 1000 yard matches. I've won a few using 7.62 Garands and bolt guns using 168's. Some folks have done the same using M1A's with match-tight 22-inch barrels. All you need to do is shoot them fast enough. But then, that's the rule with any bullet in any caliber for long range matches.

Myth busted.
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Old March 27, 2009, 08:01 AM   #2
Jim Watson
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Kind of a ragged edge type thing. When I first started shooting a little Long Range, there was a guy who amazed everybody with good 1000 yard scores from 168 gr SMK in .308. Later things had gone to pot. Different lot of bullets, different lot of powder, barrel wear, I don't know; but something had changed and it ruined his game.
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Old March 27, 2009, 08:16 AM   #3
Bart B.
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Jim, he probably didn't do well due to barrel wear. Many top bolt gun shooters could tell when their barrel's throat had eroded far enough that muzzle velocity had dropped enough to be noticed. When shooting at 600 yards at the same range and shooting conditions, their recorded sight settings for zeros would start coming up in elevation. Evidence that bullets were leaving slower needing more elevation to strike center. This usually happened around 2500 to 3000 rounds of barrel life in the Hart barrels they used. And of course, thoat erosion gages prooved this to be the cause.

This happened to me with a 7.62 Garand whose throat erosion gage read 4 in the 1965 SA barrel it had, so I took the M1 back to the shop that built it and they replaced the barrel (in 10 minutes, mind you!!!). It did very, very well after that with the same batch of handloads with 168's at 1000 yards.

Last edited by Bart B.; March 27, 2009 at 08:30 AM.
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Old March 27, 2009, 08:22 AM   #4
kraigwy
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Yes there are some Tight M14/M1As that can work. But on the whole, Most wont shoot 168s at 1000 yards.

Bolt guns and M1s ('06) can shoot them a bit faster then the standard of 2550 FPS of the M14s.

Why chance it, you're gonna be better off with the 175s (or the pre-175 180 SMKs).

There are exceptions, but with most M14/M1As you are gonna get key holing and flyers.

In heavy wind, we even switched to the heavier bullits at 600 yards, they do make a differance.
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Old March 27, 2009, 11:34 AM   #5
30Cal
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If you look at the various match bullets at their nominal velocities (the 155's, 168's and 175's), the 168 is the worst of the bunch for wind drift.
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Old March 27, 2009, 11:52 AM   #6
Bart B.
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30Cal, most folks shooting the original 155 do so from 30 to 31-inch barreled Palma rifles. Their nominal muzzle velocity is 3000 to 3100 fps. Under these conditions they buck the wind better from them better than the 168's do from more conventional barrel lengths. But the 168 has less drag that the old 155.

Sierra's newest 155 has less drag than the original; better than the 168.

Last edited by Bart B.; March 27, 2009 at 12:46 PM.
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Old March 27, 2009, 09:16 PM   #7
Ken O
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Bart, if your winning 1000 yard matches with a Garand using a 168 SMK, you have my respect! If it works for you, go for it.

A friend I shoot with is a ballistician, I had a discussion with him last summer on this issue. He did studies on the reason they get erratic, and it came down to the way the boat tail is designed, it caused some kind of turbulence that showed its face at the long yardage. The SMK is the only one designed like that, the other 168s work fine according to him. This suff is over my head, I just go with seems to be working for the top shooters. If you would like to discuss it with him, I'll get you in touch.

I have heard success stories as yours and don't doubt it happens. But, there are much better choices in bullets for that yardage, so why take a chance?
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