July 8th, 2017

200-Yard Tunnel Test — Ten Shots in One Ragged Hole

Sierra Bullets indoors testing barrels
NOTE: There are ten (10) shots in the group, but for simplicity we are only displaying five (5) shot circles. Adding more circles won’t change the measurement because the two most distant shots, which determine group size, ARE included.

What kind of 200-yard accuracy can you get in an enclosed, underground test range? Would you believe 0.162 MOA at 200 yards with a .338? Have a look at these test targets from Sierra Bullets. Like most bullet manufacturers, Sierra does live-fire bullet testing to ensure that Sierra projectiles perform as promised, with repeatable accuracy. Sierra tests bullets in its own underground test complex. Sierra’s 300-meter test range is the longest, privately-owned underground bullet test facility in the world. Sierra offers free tours of the test tunnel as part of Sierra’s Factory Tour Program.

Sierra Bullets indoors testing barrels

Day in and day out, various bullet types are tested using a big collection of barreled actions. These barreled actions are clamped in stout, return-to-battery test fixtures. These big, heavy test fixtures provide near-perfect repeatability (with no human-induced holding or aiming errors).

Sierra Bullets 10-Shot Groups at 200 yards
Check out these 10-shot test groups shot at the Sierra Test Range at 200 yards. Note that the numbers listed on each sample are actual measurements in inches. To convert to MOA, cut those numbers in half (to be more precise, divide by 2.094, which is 1 MOA at 200 yards). For example, the 0.340″ middle group works out to 0.162 MOA at 200 yards.

Sierra Bullets indoors testing barrels

Sierra Bullets indoors testing barrelsScan-Verified 0.162 MOA Accuracy at 200 Yards
To verify the accuracy of Sierra’s measurements, we measured the middle (.338 caliber) 10-shot group with our On-Target Group Measurement software. We registered a group size reading of 0.339″ — within one-thousandth of the Sierra measurement. The calculated group size in MOA (Minute of Angle) is 0.162.

That’s amazingly good for ten rounds of big .338 caliber bullets. A FIVE-shot 0.162 MOA group at 200 would be considered excellent at any benchrest match. But remember this target has TEN shots. The current, one-target IBS world record for ten shots at 200 yards is 0.245″, set by Ed Watson in 1999.

Bevy of Barreled Actions for Bullet Testing
Sierra Bullets uses dozens of barreled actions for testing bullets in its enclosed, 200-yard test range. Each barrel has its own logbook to track the barrel’s usage.

Sierra Bullets indoors testing barrels
Click Photo to Zoom

Similar Posts:

Tags: , ,