3 ms·
Based on my understanding of the physics involved, it's entirely possible that the rifle has accelerated to the recoil velocity by the time the bullet leaves th
by ufmace 8y ago
Based on my understanding of the physics involved, it's entirely possible that the rifle has accelerated to the recoil velocity by the time the bullet leaves the barrel, yet not actually moved measurably yet.
- mirimir 8y agoWell, but he says that he's measuring acceleration, not velocity. The bullet's in the barrel for just ~2 msec, and there's appreciable acceleration -- not just movement -- for >50 msec. It's true that his custom accelerometer only records data at ~6 msec intervals, but I don't see how that could smear ~2 msec out to >50 msec. Unless maybe there's some design limitations of the sensors that he used. The PRB covers the role of propellant gases in recoil, and measures effectiveness of muzzle brakes.[0] He talks about 20%-50% reduction in recoil with muzzle brakes. And that implies that gas expansion from the muzzle accounts for at least 50% of recoil. Even so, some additional measurements might be useful. It'd be interesting to know, at sub-msec sampling rates, the velocity of gas leaving the muzzle. And if there's still appreciable unexplained recoil: 1) the length of the barrel; 2) the displacement of the barrel from the stock; and 3) the diameter of the barrel, measured at maybe 4-5 points from the chamber to the muzzle. Because steel is, after all, notoriously elastic. And the barrel may be attached to the stock in a way that smears out recoil. Also, the rifle may have other recoil-management features that reduce recoil, and smear it out. It's bolt-action, so there's no blowback, and I don't see a muzzle brake, but ??? 0) http://precisionrifleblog.com/2015/07/01/muzzle-brakes-recoil-primer-test-equipment-rifles/ http://precisionrifleblog.com/2015/07/01/muzzle-brakes-recoi...