August 11th, 2016

New DTAC 115gr Rebated Boat Tail Bullet from David Tubb

DTAC David Tubb 115 grain Sierra Rebated Boat tail bullet 0.620 BC

David Tubb has come out with a new, improved version of his heavyweight 6mm match bullet. David’s new DTAC 115gr 6mm projectile is very slippery — the tested G1 1000-yard BC is 0.620. The DTAC 115 features a Rebated Boat Tail (RBT) design and a factory-pointed tip (what David calls a “closed nose”). This bullet is in production now, priced at $145.00 for 500 bullets. David tell us “the new DTAC 115 has arrived” and his company is currently filling backorders. New orders will be taken at DavidTubb.com starting Monday, August 15th. You can also call 806-323-9488 (8:30 am-4:30 pm CT) to order.

David explained the two main reasons why the Rebated Boat Tail (RBT) design was chosen for the new DTAC 115 bullet:

1. It is easier to precisely hold tolerances when manufacturing the 7 degree boat tail angle. Most conventional boat tails have 9 degree angles (or greater).

2. The RBT more efficiently obturates to the bore of the rifle barrel when fired. (It mimics a flat base bullet design). This will allow the RBT design to extend your accurate barrel life by reducing gas leakage around the bullet when fired in a worn 6mm throat.

NOTE: David does NOT claim the RBT offers a higher BC compared to a conventional boattail design.

DESIGN FEATURES: DTAC 115 Bullet with Rebated Boat Tail

Commentary by David Tubb
In the 1980s we shot 107 grain weight-range 6mm bullets for Silhouette and High Power competitions. Lower recoil and good wind drift were paramount in coming to the 6mm bullet diameter.

DTAC David Tubb 115 grain Sierra Rebated Boat tail bullet 0.620 BCAfter I developed the 6XC case around 2003 I approached Sierra about making me a 6mm bullet in the 115 grain range. Sierra ran prototypes in 112, 115, and 120 grain configurations. I thoroughly tested these and decided on the 115 grain. In 2004 I used these at Camp Perry and the result was a Long Range National Championship Aggregate with a perfect 1450×101 score. Enough said….

In 2007 Sierra had just introduced its plastic-tipped bullets. I had them run a test batch of plastic-tipped 117 grain weights. These didn’t pass my criteria.

We then ran another test batch of 111 grain plastic tip 6mm bullets and they looked great in the Sierra tunnel tests. However when shot them over an Oehler 43 at 1000 yards the results indicated the plastic tips were deformed or nonexistent at the target. These didn’t pass my criteria.

FYI — that plastic tip deformation testing information preceded the Hornady “Plastic tips Are Bad” advertising campaign by more than seven years.

When using a .308 early in my High Power rifle career we shot 190 grain Sierras at the 600-yard stage. When 600-yard accuracy began to fall off a switch to a 185gr Lapua rebated boat tail brought the accuracy back. I remember shooting some very high X-Count scores with 185gr Lapuas. The reason the Lapua worked in a worn barrel is because the rebated boat tail allows the bullet to obturate to fit the worn throat and prevent less gas leakage around the bullet when fired.

I had a bullet-maker friend reform some 6mm 115s with a rebated boat tail (RBT) in 2015 and had excellent results. So it was a natural move to redesign the current DTAC 115 6mm with a RBT and a 7 degree boat tail.

Ballistic Coefficent and Stabilization

High BC Confirmed
David says, “The new DTAC 115 RBT testing is complete and [we] can claim a G1 1000-yard BC of 0.620″.

Required Twist Rate for Stability
David reports: “This bullet stabilized out of true 1:8″ twist or faster barrel at velocities approaching 3000 fps at sea level”.

Permalink Bullets, Brass, Ammo, New Product 8 Comments »
July 30th, 2015

New Ultra-High-BC, Solid Bullets from Warner Tool Company

Flat Line High BC bullet Warner Tool Company

Warner Tool Company (WTC) has introduced a new series of “Flat Line” ultra-high-BC bullets. These sleek, lathe-turned solids are some of the most perfectly-streamlined projectiles ever sold. The Ballistic Coefficients (BCs) of Flat Line projectiles are as much as 20% higher than other match bullets of similar caliber and weight. For example, the .30-caliber 200gr Flat Line bullet has a claimed G1 BC of 0.780. Compare that to 0.555 for the Sierra 200gr MatchKing and 0.622 for the Berger 200gr Hybrid.

The new Flat Line bullets all show extremely high Ballistic Coefficients for their weights:

Caliber Description

Twist Rate

3000-1500 fps 3500-1500 fps
G1 BC G7 BC G1 BC G7 BC
30 155.5gr Palma 10 0.553 0.285 0.576 0.290
30 175gr FTR 10 0.678 0.340 0.694 0.348
30 200gr 9 0.780 0.391 0.796 0.399
33 255.5gr LRBT 10 0.814 0.400 0.834 0.411

WTC also claims that Flat Line bullets can be launched at faster velocities than other bullets of similar caliber and weight. In its marketing materials, WTC says that Flat Line bullets deliver “Higher velocities when compared with projectiles in its weight class [and] much higher velocity when compared with projectiles of similar BC.” For example, WTC claims that “the 155.5gr .30-caliber bullet has the velocity of a 125-135gr bullet [with] the BC of a 185-200gr bullet.” It will be interesting to see if these claims can be verified in field tests.

Here are comparative G1 BCs for a variety of large .30-caliber bullets:
Flat Line High BC bullet Warner Tool Company

Cal Zant of the Precision Rifle Blog has obtained some early-production Flat Line bullets from their designer, Josh Kunz. Zant has written a lengthy article explaining the design and features of the new Flat Line bullets. If you are considering ordering some of these new lathe-turned solids, you should definitely read Zant’s report.

READ Flat Line Bullets Product Report in Precision Rifle Blog.

These bullets were designed by Aerospace engineer Josh Kunz using advanced computational fluid dynamics (CFD) to simulate supersonic air flow around the bullets. Through the use of advanced modeling and precision CNC machining, Kunz has developed extremely uniform, ballistically “slippery” bullets that fly faster and flatter than other projectiles of similar weight/caliber.

Premium Pricing: Flat Line Bullets Cost $125 to $165 per Hundred
These new Flat Line solid bullets are pricey. The 155s cost $1.25 per bullet and the price goes up from there. If you need large quantities of projectiles for a week-long match, the cost can be daunting. One hundred fifty of the 200-grainers will set you back $435.00! Here is a price list for the new Flat Line bullets. All quantities are in boxes of 50. Pricing is introductory and subject to change.

.30 Cal 155 grain $62.50 per 50-ct box ($1.25 per bullet)
.30 Cal 180 grain $67.50 per 50-ct box ($1.35 per bullet)
.30 Cal 200 grain $72.50 per 50-ct box ($1.45 per bullet)
.338 Cal 255 grain $82.50 per 50-ct box ($1.65 per bullet)

Is the cost worth it? When you look at the overall expense of attending a major match, and the fact that the top places in big matches are sometimes are decided by a single point (or X-Count), some competitors will spend the extra money for these ultra-high BC solids.

For more details or to place an order, visit Warner-Tool.com, call WTC at (603) 352-9521, or email info [at] warner-tool.com. CLICK HERE for WTC Flat Line Bullets Data Sheet (PDF).

Photos and Comparison Chart copyright PrecisionRifleBlog.com. Story tip from EdLongrange.

Permalink Bullets, Brass, Ammo, New Product 20 Comments »