MDT Builds World’s Longest Rifle To Find Out How Long Is Too Long By: Hrachya H


A couple of months ago, we took a look at an amazing MDT project where they made the world’s tallest scope base that resulted in 20″ scope height over bore, to find out if scope height matters for long-distance shooting. Today, we have another mind-blowing MDT project. The company’s engineers built a bolt action rifle with a six feet long barrel to see what effect barrel length has on the projectile’s velocity for a given cartridge (.308 Win in this case) by gradually cutting the barrel down. Who makes 6-feet long barrel blanks? Nobody, the barrel of this experimental rifle was made by screwing together two barrels! MDT claim that with an overall length of 88 inches, their project gun is the world’s longest rifle.

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What is the perfect barrel length, and how long is “too long”?

If you’ve been with us for any length of time, you know that burning questions like this don’t last long unanswered at MDT, but as usual, how do we take this to the extreme?

After some initial discussions with friends and colleagues, we teamed up with Bob Jury over at Jury Barrels, and our own Engineering Team to create something that, well, you need to see for yourself. Check out the video above where we cut this build down inch by inch keeping track of velocity along the way, the results were not what we had expected.

P.S. Note the folding buttstock, to keep it “compact” 🙂

Cutting The World's Longest Rifle To Find The Perfect Barrel Length 1-22 screenshot

If you couldn’t watch the video, the chart below shows how the experiment went. The MDT engineers used Federal Gold Medal Match ammunition loaded with 175grain Sierra MatchKing bullets that have an advertised muzzle velocity of 2600fps from a 24″ barrel. Contrary to what many people would predict, the 6-feet long barrel did not slow down the projectile because of the friction – the muzzle velocity was 2785fps. In the first 20 inches of cutting the barrel, there was not much velocity drop – only 20fps per 10 inches. At around 30″ to 34″, every inch cut off of the barrel resulted in about 15fps of velocity drop. They cut the barrel all the way down to 19″ at which point the muzzle velocity was 2567fps.

Cutting The World's Longest Rifle To Find The Perfect Barrel Length 7-1 screenshot

What an amazing experiment, isn’t it? I can’t wait to see what the mad scientists at MDT will show us next. What would you like to see tested in the MDT way?

Pictures by MDT,