December 16th 2021. Some guys shoot 3-shot groups for load development. Others shoot 5-shot groups or 10-shot strings. Sierra Bullets is the best for testing projectiles. Sierra was testing its 175gr HPBT MatchKing.30-Caliber MatchKing in the Sierra underground tunnel. Below are the results: Five Hundred Rounds! 500 Shots Form 0.82 MOA Group at 300m (328 Yards).
Sierra’s trigger-pullers sent five full boxes bullets downrange at one target. The photo shows 500 shots taken in a 300 meter tunnel. The raw group size is approximately 3.13 inches from edge to edge of farthest shots. This is as shown on the calipers’ metal linear scale. Add a.308 to get the 2.823? Nominal bullet diameter* to get the 2.823. on the digital readout. You are seeing a 2.823? group at 300 meters (328 yards). At this distance, the MOA is 3.435. This means that the distance between 500 rounds and the nearest MOA is 3.435? The cartridge was.308 Winchester and was loaded at 2.800?. Reloder 15 was used for the powder. 26? barrel was shot from a return-to-battery rest. The gun was cleaned after each 125 rounds, and two foulers were shot. One Facebook poster joked that the “500-round group” was absurd. Everyone knows that anything less than 1000 rounds is a waste of time, and statistically irrelevant. Sierra’s 300 Meter Testing Tunnel
Ever wonder where and how Sierra tests its bullets? The answer is underground in a 300-meter tunnel under Sierra’s factory, Sedalia, Missouri. The tunnel was built in May 1990. Sierra conducts live-fire bullet testing on its projectiles, as do most bullet manufacturers. Sierra’s 300-meter underground bullet testing facility is the longest of its kind. Sierra used to offer free access to the test tunnel in years past as part of factory tours. * To get an exact group size, subtract the TRUE bullet holes size. This is usually smaller than what the nominal bullet diameter is. E.g. A.308 bullet hole might appear on paper as.298. We are simply subtracting.308 here. We don’t have the original target to measure.
Similar Posts:Tags: .308 Win Accuracy, 500 shot group, Sedalia MO, Sierra Bullets, Test Tunnel
