308 Winchester load development: Sierra 168 gr. MatchKing with IMR 4064 and VARGET

In the days before the 175 gr. Sierra MatchKing (SMK), the 168 SMK ruled supreme in the 308 Winchester.  Back then it was  sometimes referred to as a “heavy match” bullet since it was a step up in weight from the 147-150 grain projectiles (I actually had a Khales 26mm tactical scope cammed for it with “HM” inscribed on the turret).  Loaded in Federal’s Gold Medal 308 ammunition, this cartridge became gold standard for factory ammunition and Law Enforcement Sniper use throughout the world.

While it may have fallen out of favor to the 175 gr. projectiles for shooting past 800 yards, it is still an excellent option for the 308 Win.  Easy to load and tune, there is good reason the 168 SMK is and was so prolific.

308-bullets-168-smk-175-smk-175-tmk-190-smk-195-tmk

The 168 SMK (above, left) has a fairly conservative ogive and boat tail shape that make it easy to tune.  I consider it one of the better options for 308 along with the (above, second from left to right) 175 SMK, 175 TMK, 190 SMK and 185 TMK.

sierra-168-smk-number-2200

Fed 168 GM

You’ll often encounter the 168 SMK loaded in Federal’s Gold Medal Ammunition.  This is the standard for factory match ammo.  Over the years, I’ve never found factory a load that shoots as well in as many guns as this.

Having overlooked the 168 SMK in my main 308 rifle, I decided it was time to begin working up some loads.

od-308-close

The test gun is a custom built Remington 700 chambered with a Manson 308 Match reamer.  Referred to as “OD 308” in my range book and notes, this rifle is one of my favorite shooters.  It was built with the following parts from Brownells:

To learn more about how I built this rifle, take a look at Building a Custom Remington 700 .308 Tactical Rifle.

Trying to pick a powder to start load development with for the 168 SMK was a no brainer.  The obvious choices were IMR 4064 and Varget.  I’ve had great luck with both so I decided to give them both a shot.

WARNING: The loads shown are for informational purposes only.  They are only safe in the rifle shown and may not be safe in yours.  Consult appropriate load manuals prior to developing your own handloads.  Rifleshooter.com and its authors, do not assume any responsibility, directly or indirectly for the safety of the readers attempting to follow any instructions or perform any of the tasks shown, or the use or misuse of any information contained herein, on this website.

Using a overall length gauge, I determined that in my rifle, the the bullet will touch the lands at an overall length 2.850″.  For testing purposes I loaded to a generic length of 2.800″ (SAAMI maximum is 2.810″).

These loads are shown for reference purposes only.  Please READ THE DISCLAIMER on this site before proceeding.

I headed to the range with my OD 308.  Targets were 2″ orange dots targets at 100 yards.  All shooting was done prone, from a bi-pod with a rear bag.  The Nightforce 3.5-15 scope was set at 15x.  All ballistic information was recorded with a MagnetoSpeed barrel mounted ballistic chronograph.  Temperature was 63F.

I used Lapua brass that had been previously fired 10 times in this rifle (that’s right, 10 times)!  To size the brass, I used a Redding Competition Bushing Neck Die with Titanium Nitride bushings.  This prevents working too much of the case and has provided me long case life with all of the rifles I’ve used these dies for.

Primers are Wolf large rifle hand seated with a Sinclair priming tool.  For some reason less informed shooters seem to confuse the quality of Wolf’s center fire ammunition with the quality of their primers.  Russian primers are excellent and I’ve found they produce some of my most consistent results with cases that use a large rifle primer.

The results are shown below:

168-sml-308-loads-table-4064-and-varget

4064-and-varget-168-targets

Muzzle velocity ranged from 2,660 to 2,817 feet a second with an average of 2743 feet/second.

Standard deviation ranged from 5.3 to 17.4 feet/second with an average of 10.6 feet/second.

Group sized ranged from .318″(.304 MOA) to .985″ (.941 MOA) with an average group size of .620″ (.592 MOA).

308-win-43-5-irm4064-100-yards-5-shots

The 43.5 gr. IMR 4064 group was the smallest at .318″ (.304 MOA) with a velocity of 2,712 feet/second and a SD of 9.7 feet/second.

308-win-44-5-imr4064-5-shots-at-100-yards

The 44.5 gr. IMR 4064 load looked great as well.  Five shots into .409″ (.391 MOA) with a velocity of 2,756 feet/second and a SD of 8.1 feet/second.

308-win-45-5-varget-5-shots-at-100-yards

The best Varget group was .432″ (.413 MOA), this one was 4 shots (I only had 49 cases in this lot).  Muzzle velocity was 2,765 feet/second with a SD of 5.3 feet/second.

I had been using the 168 SMK for T and E purposes on test rifles, however, I never spent much time working on load development with them.  Turns out I was missing something, these bullets shoot extremely well.  Moreover, they seem to be slightly easier to tune than the 175 SMK.

168-175-190-185-comp-308-2The table above compares select loads developed in the test rifle.  At shorter distances, the 168 SMK doesn’t give up much, especially when hand loaded to a higher velocity.   When compared directly to the 175 SMK, the 168 SMK holds its own fairly well out to 600 yards.

As far as comparing IMR 4064 and Varget as powders, I feel IMR 4064 has a slight edge.  It is worth noting that Varget does meter much better and seems to work better in the 6.5 cartridges I load for.

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