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.308 Winchester Cartridge Guide
Accurate, Versatile and Hard-Hitting, the .308 is Truly a Do-It-All Caliber
(from http://www.6mmbr.com/308Win.html - http://www.6mmbr.com/308Win.htm l)
.308 Win, 308 Winchester Data, .308 Caliber, .308win ammo and 308 win 30-caliber 7.62 thirty cal
 | The .308 Win--MVP of Modern Cartridges | Originally
created by the U.S. Army to replace the 30-06, the .308 Winchester
(7.62x51 in military form) ranks among the most versatile and popular
centerfire cartridges in the world. The .308 serves police and
military marksmen, Palma competitors, F-Class shooters, and
deer-hunters equally well. The .308 Win delivers superb accuracy along
with outstanding barrel life--it's not unusual for a .308 barrel to
return 5,000+ rounds of accurate service. Along with excellent
factory-loaded ammo, a huge selection of bullets and powders is
available for the .308 Winchester reloader. Loading for the .308 Win is
relatively easy. The round is not finicky and great powder and
projectile combinations are well-known.
And if you want "out of
the box" precision in a factory rifle, the .308 Win is hard to beat.
While it may not be the "ulimate" 1000-yard cartridge or short-range
paper-puncher, the .308 remains one of the best cartridges in the
modern arsenal, with versatility that few other calibers can match. As
a "do-it-all" cartridge that can take game, win shooting matches, and
defend against foes, the .308 Winchester has few rivals.
.308 Preferred Brass For a 6BR, there
is one clear choice in brass--Lapua, with Norma the only real second
choice. For the .308 Winchester, choice of brass is not so simple. Most
of the .308 Win precision shooters we've interviewed do prefer Lapua
brass, but others are very happy with Norma, Winchester, Hornady Match
and even Remington. Black Hills uses Winchester-made brass for its
match ammo, which is capable of .5 MOA or better in many rifles. The
main advantage of Lapua brass is consistency and quality. Case-wall
thickness is very uniform and most lots have shown less variation in
weight than other headstamps. But Winchester brass performs very well
in the .308. And, at $24/100, Winchester costs 40% less than Lapua
brass. Even if you can potentially get more loadings out of a Lapua
case, Winchester brass offers more bang for the buck. You'll find a lot
of once-fired Federal Gold Medal Match brass available. While it tends
to shoot accurately, we've found GMM brass is relatively soft compared
to Lapua or Winchester, so the primer pockets tend to loosen up after
just three or four reloadings.
In addition to commercial brass, many .308 Win shooters reload
boxer-primed military cases such as Lake City, IMI, and Hirtenberger.
The Lake City Match brass is pretty good. Some lots have been
excellent. The standard Lake City fodder is inferior to Winchester. IMI
brass has a reputation for being strong, but we advise you only to
purchase it new. Some used lots of IMI brass from Israel have been
defective. If you are looking for ultimate accuracy, IMI will probably
disappoint you, though it's good for gas guns that are tough on cases.
The most important thing to remember about military brass is that
the internal capacity will probably be less than commercial .308 Win
brass, because military brass often has thicker webs or casewalls.
Montana Marine reports his fire-formed milsurp cases hold 56 grains of
H20 on average compared to 58 grains for fire-formed Winchester. Given
the reduced capacity of military brass, you should reduce posted max
loads by 1.5 grains when loading with Lake City or most other milsurp
brass. However, the IMI MATCH brass is closer to commercial brass in
internal case capacity (ICC). Kevin Beggs reports: "Fired, my IMI Match
brass runs with an ICC of 55.0gr and bumping the shoulder back .001"
will net me an ICC average of 54.0gr. LAPUA runs an average of 54.4gr
and Federal runs an average of 54.3gr ICC." Winchester load data, 30-caliber and .308 Win precision rifle information
Match Bullets What you see
below is just a fraction of the quality 30-caliber match bullets
available to .308 shooters. Figure there are at least twenty
projectiles you might consider. Still, with such a large selection,
nearly all the competitors we interviewed were using one of five
bullets: 155 Berger, 155 Lapua Scenar, 155 Sierra MK, 168 Sierra MK, or
175 Sierra MK. A few guys have had good luck with the 168gr Amax (.475
BC), and some guys like to shoot the heavy 185gr Bergers (.569 BC),
185gr Scenars (.521 BC), or 190gr SMKs (.533 BC) at 1000 yards, but the
vast majority of .308 shooters are running the 155s, or the 168 or 175
Sierras. Among the 155s, John Whidden has had great success with the
Bergers seating them well in the lands. The Lapua 155 has an impressive
.508 BC (and you can see that it is even longer than a 175 MK), and you
can launch it much faster than a 168- or 175-grainer. Between the 168
SMK (.488 BC) and 175 SMK (.505 BC), most shooters seem to think the
slippery 175 is a better bullet overall and it definitely has an edge
at longer distance--less drop and less windage. We suggest, in
developing initial loads for your .308, that you focus on one of these
five projectiles, and then maybe try a few Amaxs or the heavier SMKs.
Sierra will start selling a new 210gr SMK early next year. It's
probably a little heavy for a .308, but it should work very well in a
300WM or 30-06.
Hunting Bullets The
major bullet manufacturers, Barnes, Hornady, Nosler, Sierra, Speer, and
Swift provide a wide variety of hunting bullets in .308 caliber with
weights ranging from 100 grains or so to 240 grains. For smaller game
and varmints, the Sierra 110gr Varminter bullet has proven very
accurate. For deer-sized game, a bullet in the 150-grain range (such as
the Swift Scirocco) running 2850+ fps is very effective. Reader M700
tells us: "Something that is deadly accurate and has fast expansion
gets my vote for mid-longish range deer hunting. Say either a Nosler
Ballistic Tip or a Sierra SPBT GameKing. Both have the reputation for
fast expansion and excellent accuracy. With a decent .308 Win you can
boot the 150 up to around 2900 fps and get excellent accuracy as well
as deadly on-game performance." The Hornady 165gr SST, with its
excellent .447 BC, is another good choice for longer-range shots on
deer. For Elk and large game, select a heavier, controlled-expansion
bullet such as the 180gr Nosler Partition.
Factory Loaded Match Ammo
One
of the great things about the .308 Win is the availability of
high-quality factory-loaded ammo. Using 168gr Federal Gold Medal Match
this editor managed to coax a .75-moa group from a FAL clone with iron
sights. Many shooters who don't have the time to reload shoot GMM or
Black Hills exclusively, and they hold their own in tactical
competitions. Jacob Gottfredson, noted writer for Precision Shooting,
told us that he often uses Black Hills match ammo in competition: "In
tactical matches, an extra quarter-MOA of accuracy (from handloads)
won't make you a winner if you can't range the targets and dope the
wind. You could shoot 175gr Black Hills the whole match and easily end
up with a trophy". Along with Federal and Black Hills, Lapua makes
truly outstanding .308 match ammunition fitted with 155gr, 167gr, or
185gr Scenar bullets. The Lapua ammo is capable of shooting under
half-MOA in a good rifle. It costs about $25.00 per box of 20 from http://www.grafs.com/ - Grafs.com . For great prices on Federal GMM ($16/20 for 168s) go to http://www.outdoormarksman.com/ - OutdoorMarksman.com .
So
which factory ammo is the best? Chances are you should try Black Hills,
Federal and Lapua and let your gun decide. SniperCentral.com recently
conducted a http://www.snipercentral.com/ammocomparison.htm/ - Match Grade Ammo Comparison
test, including M118 LR, used by U.S. military snipers. The tester
concluded: "The Federal Gold Medal Match is still the standard by which
all other match ammo is judged. How they can get such good accuracy and
consistency from such mass produced ammo is a mystery to me. Black
Hills match grade ammo is right up there with Federal, is just as
consistent, and in my particular rifle, is just as accurate, though I
cannot say its any MORE accurate than Federal. It's a good alternative,
with the price per box about $2 cheaper than Federal. The HSM ammo is
the cheapest of them all by a large margin (about $5 cheaper then Black
Hills, and about $7 cheaper then federal per box). But it's also not
nearly as accurate. You can expect the same accuracy as M118, and it
makes a good replacement for those that cannot get M118."
Choosing the Right Powder and Load Testing For
the 160-175 grain boattails used by the majority of .308 shooters, you
want a powder of medium burn rate that gives close to 100% load
density. The "classic" .308 load for 168gr SMKs is IMR 4064 with
Federal primers. However, these days Varget is probably slightly more
popular. Lot variance has frustrated Varget users, however. Jerry
Tierney has had to tweak his .308 Palma Varget load up to two full
grains to maintain optimal velocity. Tech Note: If you use QuickLOAD,
we suggest you select data for ADI 2208 rather than Hodgdon Varget.
This, we've found, will give more realistic numbers.
http://www.6mmbr.citymaker.com/f/Sierra308Win.pdf"> In
addition to Varget and IMR 4064, a half-dozen or more other powders
work extremely well in the .308 case: AA 2460, BLC-2, IMR 4895,
Reloader 15, Ramshot TAC, VV N150, and VV N540. Some folks are seeing a
little more velocity with RL15 than with Varget, but Varget is still
less temperature sensitive--important if you're running near max. Most
of the guys we know shooting the Sierra or Lapua 155s are using Varget.
For Sierra's 110gr Varminter and other light bullets, you can use a
faster-burning powder such as Benchmark or VV N135. In general, the
.308 seems to achieve its best accuracy with case-filling loads running
pretty stout pressures. For safety's sake, always start at least 10%
below recommended maximums, and watch for pressure signs carefully.
Often you can be over-pressure even without tell-tale signs on the
primer cup. One trick we use is to take a shell-holder to the range.
After firing a test case, if you have difficulty sliding it into the
shell-holder, the web has expanded excessively, meaning your pressure
is too high. For a good selection of "safe" loads, click on the Sierra
icon to download Sierra's http://www.6mmbr.citymaker.com/f/Sierra308Win.pdf - .308 Winchester Load Map .
When
choosing a load to test, keep in mind that seating depths can make a
HUGE difference in pressure. Remember that seating bullets into the
lands can raise pressures but moving 0.020" or more AWAY from the lands
can also raise pressures, because you are reducing the effective case
capacity. Many readers ask us "should I jam or jump my bullets." There
is no right answer for every gun. For every guy getting great results
at .015" jam, there is another guy doing well with a 0.025" jump. In
general, most popular .308 match bullets (Bergers excepted) are
tolerant of jump. This is certainly true of the 168 and 175 SMKs. So
don't worry that you may be sacrificing a great deal of accuracy by
loading to mag length, even if that puts you pretty far from the lands.
Primers We
wish we could say something definitive about primers--but the truth is
both Federals and CCIs are winning their share of matches. Federal
210m, and CCI BR2s have both proven accurate with all the most popular
propellants for match ammo. We can say that if you have experienced
issues with cratering and primer piercing, go with the CCIs. They have
a harder cup. Among other primers, WLRs are used in Black Hills match
ammo and they perform admirably. Russian primers are the newest thing
to hit the market, and by all indications they work as well or better
than the best domestic primers (so long as the rather hard Russian cups
are firmly seated to proper depth). Note, Russian primers are currently
distributed by PMC and retailed in PMC boxes. However, PMC will not
import them after the first of the year. AccurateShooter.com has been
informed that a large, well-known foreign ammunition company will take
over importation of the Russian primers and they should be readily
available by the second quarter of 2006.
Reloading and Die Selection Reloading
for the .308 is straight-forward. The cartridge is very forgiving and
performs exceptionally well with a wide variety of powders and bullets.
Different applications require different tools and techniques, however.
Those shooting semi-auto "gas guns" such as the M1A and FN-FAL clones
should full-length size after each firing. Palma shooters, who need to
be at near-max pressures to be competitive, should use the strongest
brass available and should pay special attention to seating depths. At
high pressures, Palma shooters can also benefit from body-sizing or
full-length sizing after each firing.
Full-length Sizing (Body and Neck):
The problem with full-length sizing is that virtually all commercial
dies reduce the neck diameter much more than necessary. This results in
excessive neck tension and can make bullets difficult to seat smoothly.
There are two good solutions to the problem, and neither is very
expensive.
1. Purchase a Forster .308 full-length sizing die.
Measure a loaded round with a bullet seated, and note the outside neck
diameter. Then send your die to Forster and for $10 (plus shipping)
Forster will hone the neck to the dimension you specify. For bolt guns,
we suggest .002" under the neck diameter of a loaded round. For gas
guns, go .003" under. Total cost is about $45.00, including the die.
2. Hornady can make you a
custom full-length sizing die for about $75.00 plus shipping. Just send
them a few fired cases and a reamer print (if you have it). They can
create a die that gives you ideal neck tension, as well as just the
right amount of sizing at the shoulder and web. Call Hornady and ask
for Lonnie Hummel. Scott Parker recently had a die like this made and
he reports: "Average runout for 65 rounds was .0004". All 65 rounds
showed less than .001" runout."
Neck Sizing Only:
If you are not working your brass too much with very hot loads, you can
probably get by with neck-sizing only. Bushing dies are convenient and
allow you to adjust tension as easily as swapping in a new bushing, but
this can contribute to build-up of brass at the neck-shoulder junction.
If you do neck-size only, you should experiment with the bushing
position. Some shooters get best results only sizing one-half to
two-thirds of the neck. Another inexpensive option is the http://www.leeprecision.com/cgi/catalog/browse.cgi?1136070942.797=/html/catalog/dies-collet.html - Lee Collet Die .
This works by squeezing the neck around a metal mandrel that extends
down into the case. Collet dies can produce very low run-out, they
don't cause brass build-up at the neck-shoulder junction, and they are
inexpensive. However, it is somewhat difficult to precisely control the
amount of tension and the collet's fingers can leave marks on your
brass. Still, some .308 shooters swear by the Lee die.
Neck-Sizing with Optional Body Sizing:
Most .308 shooters can get away with neck-sizing only for a while, but
after 4-5 firings extraction becomes difficult. Then it's time to size
the brass. An inexpensive Redding body die is the way to go. Getting
just the right amount of sizing is the hard part--you want to just size
the case enough so that it feeds and extracts easily. With some
presses, the ram must be set to "cam-over" in order to size the case
enough. This means you must first set the bottom of the die to touch
the shell-holder, then screw it down a little further, 1/8th turn at a
time. .308 Winchester Load Map | Powder | Grains | Primer | Bullet | Brass | Velocity | Comments | | Hodgdon Varget | 47.5 | F210m | Sierra 110 Varmint | Win | 3200 fps | Very Accurate Varmint Load, 2.650" COAL | | Reloader 15 | 47.0 | F210m | Hornady 110 V-Max | Win | 3200 fps | Accurate, hard-hitting Varmint Load. Try .010" into lands. | | Hodgdon H335 | 47.0 | F210m | Sierra 125 SP | Fed | 3100 fps | Sierra's Hunting Load, 26" bbl, 2.700" COAL | | IMR 4064 | 45.2 | F210m | Nosler 150 B-Tip | Win | 2843 fps | Hunting Load, 26" bbl, 2.850" COAL | | Alliant Reloader 15 | 46.2 | CCI BR2 | Lapua 155 | Lapua | 2920 fps | Very Accurate in 25" 5R bbl, .3 MOA at 300m, 2.800" COAL | | Hodgdon Varget | 45.2 | F210m | Lapua 155 | Lapua | 2830 fps | Z. Smith Tactical Match Load in 24" Accuracy Int'l, 2.850" COAL | | Hodgdon Benchmark | 44.0 | F210m | Lapua 155 | Lapua | 2895 fps | Jason Baney 100-400m Load | | Hodgdon Varget | 45.5+ | CCI BR2 | 155 SMK | Lapua or Win | 2950+ fps | Jerry Tierney Palma Load (Charge varies with lot) | | Hodgdon Varget | 47.0 | CCI BR2 | Berger 155 | Lapua | 2900+ fps | John Whidden Palma Load | | Alliant Reloader 15 | 44.0 | CCI BR2 | Hornady 168 A-Max | Lapua | 2700 fps | Very Accurate, 1/4 moa to 400 yards. 2.875" COAL. | | Alliant Reloader 15 | 42.0 | F210m | 168 SMK | Fed | 2600 fps | Sierra's Accuracy Load Savage 12VSS | | IMR 4064 | 43.5 | F210m | 168 SMK | Win | 2600+ fps | Very Accurate in 24" bbl, 2.800" COAL. | | Vihtavuori N150 | 43.5 | F210m | 168 SMK | Win | 2640 fps | J. Gottfredson's Short-Range Match Load | | Alliant Reloader 15 | 45.0 | F210m | 175 SMK | Win | 2750 fps | Very Accurate from 24" 5R bbl. | | IMR 4895 | 43.0 | Win | 175 SMK | IMI Match | 2753 fps | Very Accurate, No Pressure Signs, 2.787" COAL, .018" jump | | Hodgdon Varget | 43.0 | Russian | 175 SMK | Lapua | 2610 fps | Brad Sauve F-TR Match Load, .018" Jump | | Hodgdon Varget | 43.0 | CCI BR2 | 175 SMK | IMI Match | 2685 fps | Very Accurate, under 1/2-MOA, 2.787" COAL, .018" jump, 26" bbl | | Hodgdon Varget | 44.6 | F210m | 175 SMK | LC | na | AR10 load for magazine, 2.807" COAL | | Ramshot TAC | 42.0 | CCI BR2 | 175 SMK | IMI Match | 2705 fps | Very Consistant under 1/2-MOA, 2.800" COAL, .005" jump | | Vihtavuori N540 | 41.0 | F210m | 175 SMK | Fed | 2400 fps | Sierra's Accuracy Load Savage 12VSS | | Alliant Reloader 15 | 46.0 | F210m | Hornady 178 A-Max | Horn Match | na | Note: Hornady brass has more capacity than Lapua. 2.845" OAL | | IMR 4064 | 40.5 | F210m | 190 SMK | Fed | 2500 fps | Sierra's Accuracy Load Savage 12VSS |
| WARNING: With all loads, ALWAYS START 10% LOW and work up incrementally. |
| Factory Reloading Data |
|---|
| http://www.accuratepowder.com/loaddata_caliber_rifle_standard.htm - Accurate Arms | http://recipes.alliantpowder.com/rg.taf?_function=centerfire&step=1 - Alliant Powder | http://www.hodgdon.com/data/rifle/308win.php - Hodgdon Powder | http://www.imrpowder.com/data/rifle/index.php - IMR Powder | http://www.lapua.com/fileadmin/user_upload/esitteet/RifleReloadingData2006.pdf" target="new - Vihtavuori (.pdf file) |
WARNING:
ALWAYS start 10% below these loads and work up. Seating depths have a
huge effect on case pressures--moving the bullet just .010" one way or
another can push a "safe" load into the danger zone. Lot variances with
powders can be extreme. Whenever you buy new powder, even the same
brand, start 10% low. NEVER assume pressures will be safe if you change
lots or ANY component. Case web growth is probably the most reliable
indicator of over-charge. By the time you're getting stiff bolt lift or
ejector marks with fresh brass you've exceeded proper pressure levels.
Ambient temperatures can alter pressures considerably. Don't assume
cold weather loads are safe in summer. As you approach max loads,
reduce the load increments. Just 0.2 grains can make a difference. Tips from Brad Sauve, 2004 F-TR Nat'l Champion With
my .308, I tried A LOT of different loads in the first 600 rounds,
starting with 42.0-44.5 N150 for the first 200 rounds, then moving to
44.0-45.0 Varget for the next 300 rounds. I tried different bullets
(Sierra 175 MKs both moly and naked, Nosler 180gr Ballistic Tips, 175gr
Bergers), different cases (Lapua, Federal), primers (Rem, CCI BR, Fed
Match), and, oh yes, seating depths (on the lands to 0.10" off, and
several distances in between). Even after 500 rounds of testing, I
still wasn't satisfied, and frankly, I was growing weary.
I
finally found my "sweetheart" load on February 14, 2000 (Valentines
Day), almost seven months after getting the rifle. This is the load I
still shoot today and I shot all weekend at the F-Class Nationals. The
break-through came when I discovered that slower velocities produced
outstanding accuracy. I found that Varget pushing a 175 SMK at about
2610 fps delivered quarter-MOA groups out to 300 yards and half-minute
or better groups beyond that distance. Since developing that load, I've
used Lapua cases and Russian primers, but the core elements, 43.0
grains Varget with 175 MKs seated 0.018" off the lands, has not changed.
During
the first few years I owned the rifle, I was crazy about cleaning. My
log shows that I cleaned the barrel 80 times in the first 998 rounds.
That works out to cleaning every dozen rounds! No wonder it took me so
long to find the right load! Boy, have I changed my habits. I still
clean the barrel, but I run a much higher round count between cleanings
than before. Now, I shoot 100-200 rounds before I give the barrel a
thorough cleaning. This goes with my general thinking--that some folks
will benefit from added trigger time more than anything else. Spend
more time shooting than loading 'perfect' ammunition or cleaning.
Squeezing that last quarter-minute out of your groups won't do you any
good if you can't hold one MOA or you can't read wind conditions. http://www.6mmbr.com/gunweek031.html - MORE TIPS from Brad Sauve . |
------------- TasunkaWitko - Chinook, Montana
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