This test was run by a company named MDT Sporting Goods. They recorded their test and it’ll be linked at the end of the post.
The company’s engineers built a bolt action rifle with a six-foot long barrel to see what effect barrel length has on the projectile’s velocity for a given cartridge (.308 Win…) by gradually cutting the barrel down. Who makes six-foot 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.
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-foot 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.
I think the main image has some solid meme potential
Testing video: [7:47] https://youtu.be/XCqa2umL8ME?si=
It’s interesting to see that the usual “wisdom” of too long of a barrel reducing FPS has been debunked at least for this caliber. But I will say that hacking about 10" off of my Mosin’s barrel closed up its group size significantly. I think because the tip of the barrel would flex and waver around like a radio antenna every time you fired it.
There’s probably some very fancy math behind the flex and resonance in a steel barrel and I’m quite certain that whatever it is, I don’t know it. But I was satisified with my redneck result.
When barrels get worn out they do so at the muzzle and breech ends first. Or if the crown of your barrel was damaged that also could have lead to poor grouping.
If either of those were the case removing some of your barrel should’ve given you better groups. That’s not to say barrel harmonics aren’t real though.
Pretty much everyone who has Bubba’d a Mosin reports that lopping off some barrel improved it. You can visibly flex the tip of the barrel on a stock one with your bare hands, and without much effort. It’s certainly possible the crown was fucked up too, though. Insofar as I’m aware my example was never fired before I got it other than possibly its original proofing.
I liked having a rifle that’s less than 5 feet long, too. It made lugging it around much easier. I think most people have very little use case for bayoneting anyone, so I was not too broken up to see the mount for that go. The $40 scout scope I put on the thing was far better than the factory iron sights ever were or could have been. There were just positives all around.
Yes, I put it in an Archangel stock worth 4 times more than the gun. Why do you ask?