November 14th, 2017

6mm Creedmoor Reloading Data From Sierra Bullets

6mm Creedmoor 6.5 Creedmoor load data Sierra Bullets

CLICK HERE for Sierra Bullets 6mm Creedmoor LOAD DATA PDF »

Sierra Bullets has recently released load data for the 6mm Creedmoor cartridge, a necked-down version of the 6.5 Creedmoor, a popular PRS, tactical, and hunting cartridge. Sierra has released very comprehensive 6mm Creedmoor load data, covering fifteen (15) different bullets from 55 to 110 grains. NOTE: Hornady-brand brass was used for Sierra’s 6mm Creedmoor load tests, not the newer, stronger Lapua 6.5 CM brass with small primer pockets. Hand-loaders using Lapua 6.5 Creedmoor brass necked to 6mm may have to adjust their loads.

Sierra writes: “As soon as the 6.5 Creedmoor was released in 2007, a 6mm version was being envisioned. After the 6mm Creedmoor demonstrated its worth at 1000 yards it began to catch the attention of Precision Rifle Series (PRS) competitors. The 6mm/6.5 Creedmoor is a great fit for those looking for an AR platform-friendly cartridge. It delivers velocities very similar to the .243 Win and yet fits the AR10 magazine length[.] The 30-degree shoulder makes this a very efficient case and helps prolong case life as well. The 6mm/6.5 Creedmoor works well with powders such as H4350, RE-17, and Ramshot Hunter for heavier long-range bullet weights. Slightly faster powders such as RE-15, Win 760, and Vihtavuori N540 work well with lighter weight bullets.”

Sierra Bullets Tested for 6mm Creedmoor Load Data
55gr BlitzKing (#1502)
60gr HP (#1500)
70gr HPBT (#1505)
70gr BlitzKing (#1507)
75gr HP (#1510)
80gr SBT (#1515)
85gr Spitzer (#1520)
85gr HPBT (#1530)
90gr FMJBT (#1535)
95gr HPBT (#1537)
95gr TMK (#7295)
100gr Spitzer (#1540)
100gr SBT (#1560)
107gr HPBT (#1570)
110gr HPBT (#1575)

In developing its 6mm Creedmoor load data, Sierra tested a very wide selection of propellants, two dozen overall. For the smaller bullets, fast-burning powders such as Benchmark, H4895, and CFE223 were tested. For the heavier 100+ grain bullets, Sierra tested a selection of medium-burn-rate powders including H4350, Reloder 16, Reloder 17, Varget, and Superformance. Sierra did a very thorough job. We know this information will be welcomed by 6mm Creedmoor shooters.

Don’t know what powder to try first? For the 107-110 grain bullets, if you want best accuracy and low ES/SD, our Forum members recommend Alliant Reloder 16 and Hodgdon H4350. If you are seeking max velocity with the 110-grainer, look at Hodgdon Superformance and Reloder 19.

Here are Sierra’s 6mm Creedmoor Load Data Charts for the 107gr MK and 110gr MK. There are a half-dozen other tables for lighter-weight bullets.

6mm Creedmoor 6.5 Creedmoor load data Sierra Bullets

6mm Creedmoor 6.5 Creedmoor load data Sierra Bullets

6mm Creedmoor 6.5 Creedmoor load data Sierra Bullets

Sierra Bullets Load Data 6mm Creedmoor reloading tips

Permalink Bullets, Brass, Ammo, Reloading, Tactical No Comments »
August 23rd, 2017

Seventy Years of Sierra Bullets — The Company History

Sierra Bullets Carroll Pilant MatchKing Bullet SMK Bullet-making Jacket
Here is the original Sierra manufacturing facility in Whittier, CA.

On August 22, 2017 it was announced that Sierra Bullets has been sold to Clarus Corporation (NASDAQ: CLAR), a Utah-based holding company that also owns Black Diamond Equipment Ltd., makers of ski and mountain gear/apparel. Given the importance of this acquisition, we thought our readers might want to learn more about Sierra’s history, and how it makes its bullets…

Sierra Bullets — How It Got Started

Report Based on Story by Carroll Pilant, Sierra Bullets Media Relations Manager
What became Sierra Bullets started in the late 1940s in a Quonset hut in California. In 1947, three aircraft machinists, Frank Snow, Jim Spivey, and Loren Harbor, rented machine space to produce rivets for the aircraft industry along with fishing rod guides and rifle front sight ramps. In the post-WWII years, sport shooting was becoming hugely popular, but quality ammunition was in short supply. For shooting enthusiasts, reloading was the solution to the ammo supply shortage. Snow, Spivey, and Harbor recognized this, creating Sierra Bullets to help fill the void. Before long, they were selling a 53-grain match bullet to the Hollywood Gun Shop. These bullets are still in production today as the Sierra #1400 53-grain MatchKing.

A few years later, an accomplished competitive shooter named Martin Hull joined Sierra. Hull helped develop new bullet types and served as manager of Sierra’s ballistics laboratory for nearly 20 years. With Hull’s help, Sierra’s output grew rapidly. The California company outgrew several locations before it moved to a large facility in Santa Fe Springs, CA, in 1963.

New Owners and New President in the Late Sixties
In 1968, the Leisure Group bought Sierra Bullets. Other Leisure Group companies included Lyman Reloading, High Standard Manufacturing Company, Yard Man, Thompson Sprinkler Systems, Flexible Flyer Sleds, and Dodge Trophies (Which made the Oscar and Rose Bowl Game trophies).

Soon after purchasing Sierra, the Leisure Group hired Robert Hayden as President and General Manager. Hayden was a mechanical engineer who had worked for Remington Arms. Hayden remained the president of Sierra for 42 years, retiring in 2012 when Pat Daly became president.

Sierra Moves to Missouri
In 1990, Sierra relocated to Sedalia, Missouri, where the company remains today. Sierra Bullets now employs over 100 people including five full-time ballistic technicians who answer daily reloading and firearms questions by both phone and e-mail.

Sierra Bullets Carroll Pilant MatchKing Bullet SMK Bullet-making Jacket

The Making of MatchKings — How Sierra Produces SMKs

All Sierra bullets begin life as a strip of gilding metal, an alloy consisting of 95% copper and 5% zinc. To meet Sierra’s strict quality requirements, the gilding metal requires three times more dimensional and quality control standards than is considered standard in the copper manufacturing industry.

Sierra Bullets Carroll Pilant MatchKing Bullet SMK Bullet-making Jacket

A blanking press stamps out a uniform disc and forms the cup that will be drawn into the MatchKing jacket. The cup is then polished and sent to a draw press to be drawn into a jacket that is longer than needed for the future MatchKing, thus allowing for the trim process. Press operators constantly check concentricity to make sure we have only quality jackets. The jackets then go to a trimmer where they are visually inspected again.

Sierra Bullets Carroll Pilant MatchKing Bullet SMK Bullet-making Jacket

After being polished a second time, the jacket travels to the bullet press. In the meantime, 80-pound lead billets are being extruded into lead wire for the cores where great care is taken so that the core wire is not stretched. The core wire is lightly oiled before continuing to the bullet press to be swaged.

The lead core wire and trimmed jacket meet at the bullet press where the first stage forms a boattail on the jacket. The lead core is then formed on top of the bullet press and fed down into the jacket. In one stroke of the press, the MatchKing is formed.

Sierra Bullets Carroll Pilant MatchKing Bullet SMK Bullet-making Jacket

Quality control technicians pull samples from each lot of MatchKings to make sure they meet Sierra’s stringent standards. Samples are then sent to Sierra’s 300-meter underground test range (shown below) to be shot for accuracy on mechanical mounts referred to as “unrestricted return to battery rests” that Sierra designed and built in-house.

Sierra Underground Tunnel test facility Sedalia, Missouri

Sierra bullet sale Clarus Corporation

After inspection, the bullets are placed in the familiar green box along with reloading labels. They are then shrink-wrapped and shipped all over the world.

Permalink - Articles, Bullets, Brass, Ammo 2 Comments »
May 11th, 2017

North Dakota Grasslands Prairie Dog Adventure

North Dakota Prairie Dog Hunt safari

Adam Scepaniak, of The Guns and Gear Store, has written an interesting story about Prairie Dog Hunting in North Dakota. If a P-Dog safari is on your “bucket list”, you’ll want to read the full story in the Sierra Bullets Blog. Adam provides many tips that can help you plan a successful prairie dog adventure.

Prairie Dog Hunting in North Dakota with Sierra Bullets (Excerpt)
It’s that time of year where lots of men and women point their vehicles westward and try to push the limits of their rifles on prairie dogs. I was a part of this group of people just a few days ago while in northwestern North Dakota. CLICK HERE to Read Full Story.

North Dakota Prairie Dog Hunt safariLittle Missouri National Grassland
Once my hunting party arrived at the Little Missouri National Grassland in North Dakota we immediately began scouting for prime prairie dog towns. There is a certain amount of strategy involved in choosing a prairie dog town … for several reasons. For one, you should try to always stay “above” the prairie dogs.

Small objects like rocks, cactuses, and prairie vegetation can easily obstruct your view if you’re shooting prone on a level plane. We encountered this in the first small prairie dog town we stopped and shot at. The prairie dog town was very visible while walking and standing, but once we laid down with our rifles on bipods the two-foot prairie grass became a severe obstruction. We shortly moved on because the small town became quick-studies to our shooting.

North Dakota Prairie Dog Hunt safari

The second prairie dog town we hunted was at the base of a small ridge with a dried, cattle creek at the bottom. This area offered better shooting opportunities because we were above most of the prairie dog holes, and if we were not above them, a deep ravine separated us from the prairie dogs removing any obstructions from our rifle scopes which was our previous problem. This area had its own disadvantage though because of some other wildlife present. There were approximately fifty head of cattle in our close vicinity grazing, which was to no surprise because many ranchers utilize the National Grassland for grazing. We had to wait for the cattle to leave our area as to not have an incidental hit due to a rare ricochet. As the sun passed over the horizon we decided to return to this spot the next morning, but would change our shooting position to increase our advantage.

This Location Offered a Nice Overlook.
North Dakota Prairie Dog Hunt safari

(more…)

Permalink Hunting/Varminting No Comments »
January 17th, 2017

6.5 Creedmoor Load Data from Sierra Bullets

Sierra Load Data 6.5 Creedmoor

Sierra Bullets has just released very complete load data for the popular 6.5 Creedmoor cartridge. This medium-sized cartridge has become one of the most popular chamberings for tactical and PRS shooters. The 6.5 Creedmoor combines excellent accuracy, good mag-feeding, good barrel life, moderate recoil, and reasonable component cost. That’s why this cartridge has caught on quickly.

Sierra Load Data 6.5 CreedmoorDeveloped in 2007 by Dennis DeMille and Dave Emary, the 6.5 Creedmoor is a shortened and improved 30 TC cartridge case that was inspired by the .308 Winchester design. This short action design was created to maximize case capacity and a wide range of loading lengths, while still fitting in standard short action magazines. With the correct twist barrel, the versatile 6.5 Creedmoor can take advantage of the wide range of bullet weights available in 6.5 mm (i.e. .264 caliber). Reloaders should keep in mind that the 6.5 Creedmoor works best with medium to medium-slow powders such as H4350, Varget, Win 760, and RE-17. The light recoil and adaptability of the efficient 6.5 Creedmoor cartridge has already proven itself in high power, precision rifle series and benchrest competitions. Couple that with respectable barrel life and its intrinsic accuracy potential and you have a recipe for success which should insure its legacy for decades to come.

Sierra 6.5 Creedmoor Load Data Manual reloading .264

Here are three tables from the Sierra Bullets Reloading Manual (5th Edition). IMPORTANT — This is just a sample!! Sierra has load data for many other 6.5mm bullet types, including FB, Spitzer, SBT, HPBT, and Tipped MK from 85 grains to 142 grains. To view ALL 6.5 Creedmoor DATA, CLICK HERE.

Sierra Bullets 6.5 Creedmoor Load Data MatchKing Tactical
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.

Sierra Bullets 6.5 Creedmoor Load Data MatchKing Tactical
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.

Sierra Bullets 6.5 Creedmoor Load Data MatchKing Tactical
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.

Permalink News No Comments »
November 2nd, 2016

NEW Sierra 6mm 110-Grain MatchKing with Claimed 0.617 G1 BC

Sierra 6mm 110gr matchking bullet BC 0.617

Sierra’s new 110gr 6mm MatchKing is so new you won’t even find it on Sierra’s website. But MidwayUSA has it listed as “coming soon”. This new bullet, optimized for a 1:7″-twist barrel, promises class-leading ballistics. The listed G1 Ballistic Coefficient (BC) is an impressive 0.617 (sorry, no G7 BC has been stated). That’s 12.8% higher than the 0.547 G1 BC Sierra claims for its older 107gr MatchKing. That’s a very significant improvement. We attribute the reduced drag of the new 110-grainer to an improved hybrid-ogive bullet shape along with much smaller meplats. Sierra has not yet confirmed that it is pointing the meplats of the new 6mm 110s at the factory, but we expect that may be the case. In this respect the 110-grainers could be like Sierra’s excellent 183gr 7mm MatchKings, which come with tight, pointed tips right out of the box.

Sierra 6mm 110gr matchking bullet BC 0.617

G1 vs. G7 and Listed BCs vs. Tested BCs — What You Need to Know

Manufacturer-listed G1 Ballistic Coefficients of 6mm Match Bullets
Sierra 110gr HPBT MK Sierra 107gr HPBT MK Berger 105gr Hybrid Tgt Hornady 108gr ELD
G1 BC = .617 @ 2500+ fps G1 BC = .547 @ 2500+ fps G1 BC = 0.536 G1 BC = 0.536

If you look at the table above you’ll see that Sierra’s claimed 0.617 G1 BC for the new 110gr MK is higher than the 0.536 Berger lists for its 105gr 6mm Hybrid and higher than the 0.536 Hornady lists for the new 108gr 6mm ELD Bullet. We do think Sierra’s 110-grainer will prove to have the highest BC of the bunch, based on recent comparison tests by Sierra.

Let’s explain… Sierra lists a 0.547 G1 BC for its 107-grain MatchKing. Sierra tells us that the the .547 listed BC is for the current lots of 107-grainers which are pointed by Sierra. Sierra’s Matt Reams states that the new 110-grainers definitely have less drag than the current Sierra 107gr MKs or Berger 105gr Hybrids: “We have shot the pointed 107s side by side (raced) in our 300-meter range next to the [Berger] 105s and our pointed 107s had a higher BC between those two lots. In the comparison we did, our lot of new pointed 107s had a slightly higher BC than the [Berger] 105s. The 110s are significantly higher than both.”

In the real world, Sierra’s new 110gr 6mm MatchKing may not have as big an edge over the competition as it seems from Sierra’s claimed 0.617 G1 BC. (The G7 numbers may be closer.) Nonetheless, we do expect that Sierra’s new 110-grainer will be very competitive, and may actually have best-in-class BC. And if the new 110gr SMKs come “tipped” from the factory that will be a very good thing.

Anybody currently shooting a heavy 6mm bullet in competition should look at the new 110gr MatchKing when it becomes available. It could prove to be a winner. NOTE However — Sierra recommends a true 1:7″-twist barrel to stabilize the new 110-grainers.

New Product Tip from Boyd Allen. We welcome reader submissions.
Permalink Bullets, Brass, Ammo, New Product, News 20 Comments »
October 26th, 2016

Great Sale on Sierra Bullets at Precision Reloading

Precision Reloading Sierra Matchking Tipped TMK SMK bullets sale

Right now Precision Reloading is running a BIG SALE on Sierra MatchKing (MK) and Tipped MatchKing (TMK) Bullets. These bullets are being offered at deep discounts, with very low prices (some close to wholesale). Precision Reloading says you can save up to $37.00 on 500-ct boxes. Here are just a few examples of the dozens of types of Sierra Bullets on Sale.

Sierra 30 Cal, 200gr HPBT MK, 100 for $35.57 (marked down from $40.29)
Sierra 7mm, 183gr HPBT MK, 100 for $38.37 (marked down from $43.39) (Great new bullet)
Sierra 6.5mm, 142gr HPBT MK, 500 for $167.74 (marked down from $187.69)
Sierra 6.5 mm, 130gr TMK, 100 for $30.58 (marked down from $34.59)
Sierra 6mm, 95gr TMK, 500 for $138.75 (marked down from $156.89)
Sierra 22 Cal, 80gr HPBT MK, 500 for $117.08 (marked down from $132.39)
Sierra 22 Cal 77gr TMK, 100 for $26.19 (marked down from $29.69)

NOTE: This Sierra Bullets Sale runs through October 31, 2016, so you’ll want to place your order before the end of the month.

Sierra offers the widest selection of .30-Caliber match bullets in the world today, producing bullets suited to nearly every form of long-range competition. Along with classic HPBT and HP MatchKings, Sierra now offers the new Tipped MatchKing (TMK) line, which feature an acetal resin tip. The major advantage of adding a tip to the bullet is the reduction of drag, producing a more favorable ballistic coefficient. Another benefit is improved feeding in magazine-fed firearms.

Permalink Bullets, Brass, Ammo, Hot Deals No Comments »
June 18th, 2016

Sierra MatchKing (SMK) vs. Sierra Tipped MatchKing (TMK)

Sierra Tipped MatchKing bullet TMK SMK Tommy Todd

by Sierra Bullets Chief Ballistician Tommy Todd

Since Sierra introduced the Tipped MatchKing® (TMK®) line of bullets in 2015, we have had a few questions from customers regarding the two lines of bullets (MK vs TMK). Some shooters are concerned that the tried-and-true MatchKing® bullets will be replaced with the Tipped MatchKing® bullets. For those of you worried, relax, the old standby MatchKings® that you have shot for years are here to stay, and we will happily continue to make them for you.

Sierra Tipped MatchKing bullet TMK SMK Tommy Todd

For those that like to try new products, we are planning on both continuing and expanding the Tipped MatchKing® line. Even where there are two bullets within these two lines that have matching weights (pictured above), 22 caliber 69 and 77 grain, 6mm 95 gr, 30 caliber 125, 155, 168 and 175 grains, we are not going to replace the MatchKings® with the Tipped MatchKing®. We are, however, going to continue to offer both lines of bullets for your use and enjoyment. Keep an eye out for new additions to our product line!

Permalink News 3 Comments »
November 25th, 2015

New 6mm and 6.5mm Tipped MatchKings from Sierra

Tactical 6.5x47 Lapua

Sierra has released two new Tipped MatchKing (TMK®) bullets that should find favor with PRS competitors and tactical shooters*. Sierra is producing a new 95 grain 6mm projectile and a new 130 grain 6.5mm bullet. Both feature acetal resin tips that lower drag by improving the ballistic coefficient (BC) and making the BC more uniform from bullet to bullet. The 95-grainer should work well as a higher-speed option in the .243 Win, 6mm Creedmoor, 6mm Dasher, and 6mmBR. We were able to push other 95gr bullets nearly 100 fps faster than 105gr bullets from a 6mmBR. For those shooting the 6.5×47 Lapua and 6.5 Creedmoor, the new 130gr TMK should be a near-ideal bullet weight. We know that Berger’s 6.5mm 130gr VLD works great in those mid-sized cartridges, so Sierra’s new 130-grainer should be in the “sweet spot”. Also, in the .260 Remington the 130gr TMK should be capable of velocities that hit predicted accuracy nodes with ease. The 6mm 95 grain TMK requires a twist rate of 1:9″ or faster to stabilize while the 6.5mm 130 grain TMK requires a twist rate of 1:8″ or faster to stabilize.

We expect the 130gr 6.5mm TMK to find favor with Tactical Shooters
Tactical 6.5x47 Lapua

* In addition, Sierra plans to add a 7mm 160gr TMK to the line-up, product #7660, but we don’t expect this to be used for tactical games because of the heavier recoil.

Permalink Bullets, Brass, Ammo, New Product 10 Comments »
October 29th, 2015

Sierra Releases NEW 183 grain 7mm (.284) MatchKing Bullet

Sierra Bullets MatchKing 7mm .284 High-BC projectile bullet F-Class New

High-BC 7mm bullets are favored by many of the top long-range and F-Class (Open) shooters. Now, thanks to Sierra Bullets, there is a new “heavy-weight contender” in the 7mm match bullet category. Sierra has just introduced an all-new 183 grain 7mm HPBT MatchKing, part # 1983. This impressive new projectile boasts a 0.707 G1 Ballistic Coefficient (at 2300+ fps), plus — get this — it comes “tipped” from the factory. The final meplat tipping operation ensures a higher, more uniform BC. Recommended barrel twist rate is 1:8″ or faster.

Sierra Bullets MatchKing 7mm .284 High-BC projectile bullet F-Class New

Sierra says its new 183gr 7mm MatchKing has a modern, low-drag shape: “A sleek 27-caliber elongated ogive and a final meplat reducing operation (pointing) provide an increased ballistic coefficient for optimal wind resistance and velocity retention. To ensure precise bullet to bore alignment, a unique bearing surface to ogive junction uses the same 1.5 degree angle commonly found in match rifle chamber throats.

The new 7mm 183gr HPBT bullets will be available in boxes of 500 bullets (#1983C) with MSRP of $256.34 per box and boxes of 100 bullet (#1983) with MSRP of $51.80 per box. NOTE: Sierra states that “MatchKing® and Tipped MatchKing® bullets are not recommended for most hunting applications.”

Permalink Bullets, Brass, Ammo, New Product 3 Comments »
December 18th, 2014

NEW Tipped MatchKing (TMK) Bullets from Sierra

Sierra has announced a new line of plastic-tipped MatchKing bullets. “Say What!? — that can’t be right…” you may be thinking. MatchKings have always been jacketed, hollowpoint bullets. Until now, plastic tips have been reserved for other Sierra projectiles, such as BlitzKing varmint bullets. But that is changing with the introduction of Sierra’s line of Tipped MatchKing (TMK) bullets featuring green acetal resin tips.

.308 30 caliber Sierra bullets tipped matchking TMK SMK

Plastic Tips Offer Better BC
Sierra says the plastic tips on TMKs enhance the Ballistic Coefficient (BC): “The major advantage of adding a tip to the bullet is the reduction of drag, producing a more favorable ballistic coefficient.” Stated BCs for the new TMK bullets are listed below. These BC numbers look good, and they have been verified with real-world testing: “We shot [all the new TMKs] multiple times (we actually test our BC numbers instead of letting a computer tell us what it is) and those numbers are all proven out!”

There will be six (6) new TMK bullets, two in .224 caliber, and four in .308 caliber. The six new tipped bullet types should be available in “early 2015″. Sorry, Sierra will not be offering 6mm, 6.5mm, or 7mm TMKs for the time being, although Sierra will introduce more TMK varieties in the future. Currently, Sierra is focusing on “the most popular calibers”. Notably, the new 22-Cal 77gr TMK has a 0.420 BC — identical to the BC of Sierra’s 80gr non-tipped HPBT MatchKing. So, you get the BC of a heavier bullet in a lighter projectile that can be pushed faster. That’s big news for .223 Rem and 22-250 shooters.

Bullet Name (Click for ballistic coefficients) Brand Item BC (G1)
.224 dia. 69 gr. Tipped MatchKing (TMK) .224 dia. 69 gr. Tipped MatchKing (TMK) Tipped MatchKing 7169 .375 @ 2700+ fps
.224 dia. 77 gr. Tipped MatchKing (TMK) .224 dia. 77 gr. Tipped MatchKing (TMK) Tipped MatchKing 7177 .420 @ 2400+ fps
.308 dia. 125 gr. Tipped MatchKing (TMK) .308 dia. 125 gr. Tipped MatchKing (TMK) Tipped MatchKing 7725 .343 @ 2580+ fps
.308 dia. 155 gr. Tipped MatchKing (TMK) .308 dia. 155 gr. Tipped MatchKing (TMK) Tipped MatchKing 7755 .519 @ 1900+ fps
.308 dia. 168 gr. Tipped MatchKing (TMK) .308 dia. 168 gr. Tipped MatchKing (TMK) Tipped MatchKing 7768 .535 @ 2050+ fps
.308 dia. 175 gr. Tipped MatchKing (TMK) .308 dia. 175 gr. Tipped MatchKing (TMK) Tipped MatchKing 7775 .545 @ 2400+ fps

New Bullet Shapes Along with Plastic Tips
In addition to the bullet tip, some of these new TMK bullets have slightly modified shapes compared to previous-generation, non-tipped MatchKings (SMKs) of like caliber/weight. Sierra’s technicians reported: “The [plastic] point on the tip is smaller than the meplat on a SMK and if you look, you will also see the ogive on most of these [new TMKs] have been changed as well. Most of the big BC gains are from the reshaped ogives from the legacy SMK product.”

TMK 7169 69 gr
TMK 7177 77 gr
TMK 7725 125 grTMK 7755  155 gr
TMK 7768 168 gr
TMK 7775 175 gr

.308 30 caliber Sierra bullets tipped matchking TMK SMK

Permalink Bullets, Brass, Ammo, New Product 19 Comments »
September 22nd, 2014

Practical Thoughts About Transonic Bullet Stability and Accuracy

One of our Forum Members has a .308 Win load that dips into the transonic speed range at 1000 yards. He is concerned that his bullets may lose accuracy as they slow to transonic speeds: “My target is at 1000 yards. How important to accuracy is it to keep the bullet supersonic (Mach 1.2) all the way to the target? How does slowing to transonic speeds in the last 100 yards or so affect accuracy?”

TargetShooter Magazine and AccurateShooter.com contributor Laurie Holland offers some practical answers to this important question, based on his his experience with .223 and .308-caliber bullets.

Thoughts on Accuracy and Transonic Bullet Speeds by Laurie Davidson.
There is no simple answer to the question “How do transonic speeds affect accuracy”. Some bullets manage OK, some not so well, some fail entirely, and I’ve never seen a guide as to which models do and which don’t. But we do have the ‘boat-tail angle rule’, anyway. Bryan Litz says the ideal boat-tail angle is 7-9°. Go much above 10° and it’s too steep for the air to follow the bullet sides around to the base. This seems to manifest itself as much increased drag and turbulence leading to instability in transonic flight.

It is this effect that has led to the common advice of “Don’t use 168gr 30-caliber bullets at 1000 yards”. That is misleading advice as it resulted from use of the 168gr Sierra ‘International’ (aka MatchKing) bullet with its 13-deg BT angle. (This was, originally, a specialized 300m design — there are various near copies on the market from Speer, Hornady and Nosler.) By contrast, Berger 168-grainers are designed as long-range bullets with 8.9, 8.5 and a really nice 7° angle on the BT, VLD and Hybrid respectively. Hornady A-Max 30-cal projectiles (other than the 208-grainer) fall into this enforced shorter-range bracket too thanks to their 12.6° (and greater) boat-tail angles. (155gr = 13.5°, 168gr = 12.87°, and 178gr = 12.6°.)

Supersonic bullet shadowgraph

Even this boat-tail angle ‘rule’ doesn’t always seem to apply. Many older long-range Service Rifle shooters talk about good results at 1000 yards with some batches of 7.62mm match ammo in their 20″-barreled M14s using the 168gn SMK. I’ve successfully used Hornady and Sierra 168s at 1000 yards in 30-cal magnums which drive the bullets fast enough to keep out of trouble at this distance. This is still not recommended of course thanks to their low BCs compared to better long-range speciality bullets.

Supersonic bullet shadowgraph 7.5mm Swiss
These four photos show the substantial changes in the shock ware and turbulence patterns for the same bullet at different velocities. The “M” stands for Mach and the numerical value represents the velocity of the bullet relative to the speed of sound at the time of the shot. Photos by Beat Kneubuehl.

Transonic Issues with .223 Rem in F-TR
I was much exercised by [concerns about transonic instability] in the early days of F-Class, when I was shooting a .223 Rem with 80-grainers at 2,800 fps MV or even a bit less. Even the optimistic G1 ballistic charts of the time said they’d be subsonic at 1000 yards. (Bryan Litz’s Point Mass Ballistic Solver 2.0’s program says 1,078 fps at 1000 yards at 2,800 fps MV in standard conditions for the SMK; below 1.2 MACH beyond a point somewhere around 780 yards.) In fact they shot fine in a large range of conditions apart from needing around 60% more windage allowance than 6.5mm projectiles [shot with a larger cartridge]. The biggest problem apart from my wind-reading skills was constantly getting out of the rhythm to call to have the target pulled as the pits crew didn’t hear the subsonic bullets and had trouble seeing their little holes.

In the early days of F-TR I used a 24″ barrel factory tactical rifle that was billed as F-TR ready — it wasn’t! The much touted 175gr Sierra MatchKing, as used in the US military M118LR sniper round, was allegedly good at 1000 yards at .308 velocities — but it wasn’t! It would group OK in [some calm] conditions, but any significant change would cause a much greater deflection on the target than the ballistic charts predicted, so transonic flight was obviously making it barely stable. I also suspect conditions on the day had a big effect as Litz’s program says [the 175gr SMK] is just subsonic at 2,650 fps MV at 1,000 in standard conditions. Throw in MV spread and there was a risk of some round remaining supersonic, while others went transonic. Plus warmer or colder air moving onto the range under some conditions might change things.

I used the combination on Scotland’s notorious Blair Atholl range at 1000 yards in one competition in a day of cold headwinds from the north and frequent rain squalls. The temperatures plummeted during the squalls (and the wind went mad too!) and what was an ‘interesting group pattern’ outside of squall conditions changed to seeing me do well to just stay on the target frame at all. On ranges other than Blair (which is electronic, so no pits crew), target markers reported they heard faint supersonic ‘crack’ and saw round holes on the paper, so the bullets appeared to remain stable and just supersonic in summer shooting conditions.

Transonic Problems with M118LR 7.62×51 Ammo
Confirmation of this transonic performance phenomenon has since come from USMC snipers who say the M118LR’s performance ‘falls off a cliff’ beyond 800m (875 yards), which is just what I found when shooting the bullet at slightly higher than M118LR muzzle velocities. A move to the 190gr SMK with Vihtavuori N550 keeping the MVs reasonable gave a vast improvement in 1000-yard performance.

Practical Advice — Use a Bullet That Stays Supersonic
The ‘easy’ / better answer to all this is to use a design such as the 30-caliber, 185gr Berger LRBT with a reputation for good long range performance and to load it to achieve or exceed 1,350 fps at 1000 yards. If I can get the combination I’m using to be predicted to hold 1,400 fps at this range in a G7-based program calculation, I’m happier still.

Incidentally, the old long-range, 30-cal Sierra bullets (the venerable 190gr, 200gr, and 220gr MatchKings), with their extra length boat-tail sections, have a superb reputation for stable transonic / subsonic flight. They were used by GB and British Commonwealth ‘Match Rifle’ shooters at 1000, 1100, and 1200 yards for many years before the current bunch of 210gr and up VLDs and Hybrids appeared.

Supersonic space shuttle waveTransonic vs. Supersonic

The term “Transonic” refers to velocities in the range of Mach 0.8 to 1.0, i.e. 600–768 mph. It is formally defined as the range of speeds between the critical Mach number, when some parts of the airflow are supersonic, and a higher speed, typically near Mach 1.2, when the vast majority of the airflow is supersonic. Instability can occur at transonic speeds. Shock waves move through the air at the speed of sound. When an aircraft goes transonic and approaches the speed of sound, these shock waves build up in front of it to form a single, very large shock wave. This is dramatically illustrated in this Space Shuttle photo.

Permalink Bullets, Brass, Ammo, Tech Tip 4 Comments »
March 9th, 2014

Black Hills MK 262 Mod 1 5.56 Ammo — Now for Civilians Too

If you shoot Service Rifle, or use a .223 Rem at medium to long range, you should read J. Guthrie’s ShootingTimes.com review of Black Hills MK 262 Mod 1 ammunition. Originally developed for military applications, this very accurate ammo is now available for civilians to purchase. It uses a special Sierra 77gr MatchKing bullet with cannelure. Black Hills did extensive testing to develop this ammunition, shooting over 250,000 test rounds with various propellants and projectiles. Eventually, the Sierra 77gr MK bullet was chosen, with a powder that delivers 2750 fps MV (from a 20″ barrel).

Black Hills MK 261 OTM Mod 1 Sierra MatchKing MK
READ Full Review of Black Hills MK 262 Mod 1 Ammunition

Sierra’s 77-grain bullet delivered great accuracy at long range. Guthrie explains: “Several bullets were used during the development process, including the 73-grain Berger, 77-grain Sierra MatchKing, and 77-grain Nosler HPBT. Black Hills finally settled on the MatchKing when Sierra agreed to put a cannelure on the bullet. In test fixtures Sierra’s bullet proved slightly more accurate. Accuracy was exceptional, certainly an improvement over M855 [military 5.56x45mm ammunition].”

Guthrie’s article explains that this ammo design started off as target ammunition developed for the USAMU. That was followed by a 1999 request from the Naval Surface Warfare Center, Crane Division for a round that would work with a suppressed, short-barrel M16 variant. Over the years, as Black Hills produced more ammo for the U.S. military, this ammunition continued to be improved. Guthrie notes: “The name changed with each modification. MK 262 Mod 0 was adopted in 2002, Mod 1 came along in 2003 with the cannelure, and an improvement to temperature sensitivity came along in 2005.”

According to Black Hills President James Hoffman, the MK 262 ammo “developed a cult following… so [in 2011] we started offering it to the public. The only difference is the packaging — it is the exact same ammunition as is delivered to the U.S. Military — loaded to the exact same specs”. The commercial version is sold in black/red 50-count boxes labeled “5.56mm 77 GR OTM”. The exact same ammo is issued to American war-fighters in 20-round, brown cardboard boxes labeled “5.56mm SPECIAL BALL, LR MK 262 MOD 1.”

Field Test of Black Hills MK 262 Mod 1 Ammunition

About J. Guthrie: Last April, at the much-too-young age of 37 years, outdoor writer J. Guthrie passed away in his sleep, leaving a wife and two young children. Field & Stream noted: “Guthrie was already a major player and a pro’s pro, but he wanted to be more. He wanted to be a Gun Writer in the old style. It’s a terrible loss for all of us that his run was cut so short.”

Story idea from Grant Guess. We welcome reader submissions.
Permalink - Articles, Bullets, Brass, Ammo, Gear Review No Comments »
May 30th, 2012

New 350gr .375-Caliber MatchKing from Sierra

Sierra MatchKing SMK .375 caliberSierra Bullets has just announced a new .375-caliber, 350 grain HPBT bullet — the latest in Sierra’s MatchKing line of projectile. Designed for custom long-range applications, this 350-grainer is the largest MatchKing Sierra produces, and it offers a jaw-dropping 0.805 G1 BC (at 2,200+ fps).

With that impressively high BC, the new .375-caliber MatchKing should “buck the wind” very well at long range. The new bullet features an 11-caliber ogive, and 9-degree boat tail. Sierra says the overall shape is “forgiving” to tune and should work well at a variety of seating depths. These bullets will be available in 50-count boxes (stock #9350T), or bulk boxes of 500 bullets (stock #9350).

Sierra MatchKing SMK .375 caliber

Permalink Bullets, Brass, Ammo, New Product 3 Comments »
December 22nd, 2011

Litz Adds 6mm Bullet Profiles for 107gr SMK and 105gr A-Max

Applied Ballistics Bullet DataAlong with showcasing his books, match ammo, and other products, Bryan Litz’s Applied Ballistics website offers detailed Bullet Data Profiles for popular match projectiles. These profiles provide accurate bullet dimensions, stability factors (based on barrel twist rates), plus sophisticated multi-value BC tables that provide field-tested BCs across a wide velocity spectrum. Using these tables, you can select a G1 or G7 BC that closely matches a bullet’s actual muzzle velocity fired from your gun. Choosing the right BC for a bullet’s known MV from your rifle provides a more accurate ballistics solution — which translates to more first-round hits on the target.

New 6mm Bullet Data Profiles

Bryan recently added two new 6mm Bullet Profiles to his website: Sierra’s 107gr MatchKing, and Hornady’s 105gr A-Max.

Sierra 107gr MatchKing, HPBT
Sierra’s 107gr MatchKing has been used reliably in many medium- to high-capacity 6mm chamberings for many years. At 107 grains, this bullet is heavy enough to have a respectably-high BC while not being excessively long. This bullet is the ‘middle brother’ in the heavy end of Sierra’s 6mm target bullet line-up. The 95gr and the 115gr bullets have essentially the same nose and tail, and almost identical form factors as a result. The only difference being the weight which is taken up in the bearing surface. This bullet is comfortably stable in a 1:8″ twist in all but the worse case conditions, and even then the stability factor is still 1.33 which would result in acceptably accurate flight.

Sierra 107 MK Litz Data

Hornady 105gr A-Max, PTBT
The 105gr Hornady A-Max is a very well-designed bullet with good performance. The plastic tip (PT) promotes a little higher and more consist BC compared to standard match bullet meplats while the 2.71-caliber long tangent ogive produces a low drag profile and good accuracy over a wide range of seating depths. The experimentally determined average G1 BC of 0.492 varies from 0.515 at 3000 fps down to 0.454 at 1500 fps. The G7 BC is a much better match for this bullet. Application-wise, this bullet was designed to be a match bullet, but has found favor with hunters as well due to the relatively thin forward jacket promoting good expansion.

Hornady 106 A-Max Litz Data

Bryan’s Ballistics Book Offers Hundreds of Bullet Data Profiles
Bryan currently offers ten (10) detailed bullet profiles on his website — you can access these for free. If you want information on scores of other projectiles, you’ll find 236 other Bullet Data Profiles in Bryan’s definitive book, Applied Ballistics for Long-Range Shooting.

Permalink Bullets, Brass, Ammo, Reloading No Comments »
November 13th, 2011

New 125 GR Flat-Based MatchKing from Sierra Bullets

Sierra has introduced a new .30-caliber flat-based bullet, the 125 grain OTM (open-tip match HP) MatchKing, item #2121. This unique flat-based bullet was designed in conjunction with AAC (Advanced Armament Corporation) and Remington for the new .300 AAC Blackout (BLK) cartridge. The bullet length is tailored to correctly fit and feed from AR-15 platform magazines. The projectile’s Open Tip is pinched for greater uniformity in the same manner as Sierra’s Palma Competition bullets. The G1 BC is surprisingly high for a relatively short, flat-based bullet: 0.310 (below 1600 fps), 0.330 (1,600-2,000 fps), 0.338 (2000 – 2650 fps), and 0.349 (above 2650 fps). Though it will perform well at low velocities in the .300 BLK, this bullet can handle the higher velocities produced by common .30 cal mid-sized cartridges, such as the .30-30.

Sierra 125 gr Matchking

Sierra 125 gr MatchkingThe new 125gr Matchking is now being loaded in factory ammo, including Remington’s Premier Match, which retails for $34.00 for a 20rd box. These 125gr bullets are available now from MidwayUSA for $34.99 per hundred. Sierra offers five other bullets in the same general weight range that may work well in the .300 Whisper or .300 AAC Blackout:

  • .308 dia. 110 gr. FMJ Pro-Hunter Item 2105
  • .308 dia. 110 gr. HP Varminter Item 2110
  • .308 dia. 110 gr. RN Pro-Hunter Item 2100
  • .308 dia. 125 gr. SPT Pro-Hunter Item 2120
  • .308 dia. 135 gr. HPBT MatchKing Item 2123
  • Permalink Bullets, Brass, Ammo, New Product 3 Comments »
    January 25th, 2011

    SHOT Show Report: Four New Projectiles from Sierra Bullets

    Sierra Bullets introduced four new projectiles at SHOT Show 2011: 180gr 7mm MK; 225gr .338 ProHunter; and two new 25-caliber BlitzKings. The much-awaited 180gr 7mm MatchKing, boasts an impressive 0.660 G1 Ballistic Coefficient. This should be great for
    F-Classers. Sierra explains: “In response to requests from top level F-Class shooters, Sierra has designed an all-new MatchKing to provide a higher weight/higher B.C. alternative in our 7mm line. This bullet’s 12-caliber secant ogive and lengthened boat tail make it the perfect choice for the discerning 7mm long range shooter. Sierra recommends at least a 1:8″ twist barrel to stabilize this bullet.”

    YouTube Preview Image

    This new MatchKing will compete with Berger’s vaunted 180gr 7mm VLD. It will be interesting to see how the two 180s perform head to head. If you are shooting a 7mm at long range, you should definitely try out the new .284-caliber Sierra MK (provided your barrel has a suitable twist rate).

    Sierra 180 grain MatchKing 7mm .284

    New .338 Hunting Bullet and two New .257-Caliber Varmint Bullets
    For the hunting crowd, Sierra has released a new .338-caliber bullet and two new .257-caliber projectiles. The new .338 is a 225gr, soft-point, flat-base Pro-Hunter in .338 caliber. Sierra’s goal with this new bullet was to provide a lower-recoiling .338 projectile that still offers plenty of hitting power.

    For varminters, Sierra has introduced two new .25 caliber (.257 diam.) BlitzKing bullets, in 70 grain (Part #1605) and 90 grain (Part # 1616) sizes. The 70-grainer is a flat-base design, while the 90-grainer is a boat-tail. According to Sierra, these were created to provide enhanced long-range performance for 25-caliber varmint hunters. We predict the 90-grainer will also be an excellent target bullet. These bullets will be available in boxes of 100 bullets and 500 bullets as indicated below.

    Sierra .257 varmint bullets

    Permalink - Videos, Bullets, Brass, Ammo, New Product No Comments »
    January 7th, 2011

    New Sierra 7mm and .338 Bullets for 2011

    New from Sierra Bullets for 2011 are two new heavyweight bullets. The first, the much-awaited 180gr 7mm MatchKing, boasts an impressive 0.660 G1 Ballistic Coefficient. This should be great for
    F-Classers. Sierra explains: “In response to requests from top level F-Class shooters, Sierra has designed an all-new MatchKing to provide a higher weight/higher B.C. alternative in our 7mm line. This bullet’s 12-caliber secant ogive and lengthened boat tail make it the perfect choice for the discerning 7mm long range shooter. Sierra recommends at least a 1:8″ twist barrel to stabilize this bullet.”

    This new MatchKing will compete with Berger’s vaunted 180gr 7mm VLD. It will be interesting to see how the two 180s perform head to head. If you are shooting a 7mm at long range, you should definitely try out the new .284-caliber Sierra MK (provided your barrel has a suitable twist rate).

    Sierra 180 grain MatchKing 7mm .284

    A New 225-grain, .338 Bullet for Game-Hunting
    The second new bullet from Sierra is a 225gr, soft-point, flat-base Pro-Hunter in .338 caliber. Sierra’s goal with this new bullet was to provide a lower-recoiling .338 projectile that still offers plenty of hitting power. Sierra tells us: “The newest member of our Pro-Hunter line is the .338-caliber 225gr SPT Pro-Hunter. The flat-based design and lighter weight of this projectile make it a great choice for medium and large game. This is a perfect choice for those hunters seeking a reduced recoil alternative where a heavier bullet is not required.”

    Sierra 225 grain Pro-Hunter .338

    Permalink Bullets, Brass, Ammo, New Product 2 Comments »