November 14th, 2022

Tunnel Vision — Amazing Accuracy in Sierra’s Test Tunnel

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 Western Hemisphere.*

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.

Scan-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.

Click Photo to Zoom

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*Even Longer Test Tunnels Exist in Europe: At Stadeln in Germany, RWS (now part of RUAG) owns a 500 meter tunnel (above ground level) which has existed for decades. In Thun, Switzerland, RUAG has a fully-instrumented 500 meter underground tunnel. Near Ulm, Germany, there is a 5-lane 300 meter underground shooting range that is open to the public.

Similar Posts:

• 10 Shots in One Ragged Hole at 200 Yards — Sierra Tunnel Test
• 10 Shots in 0.340″ at 200 Yards — Sierra Tunnel Testing
• 200-Yard Tunnel Test — Ten Shots in One Ragged Hole
• Ten Shots, 200 Yards, One Ragged Hole — Sierra Bullet Testing
• A Look Inside Sierra’s 300m Underground Test Tunnel

Tags: .338 Lapua, 10-shot groups, 300 meter tunnel, Sierra Bullets, Sierra Test Tunnel