The barrel movement produced from start to crown is the important, what happens after you see the exit gasses emerge(barrel whip)- is not important at all. There is alot on this barrel that is really not needed. All you need (not always) is the limbsaver at correct location to dampen the amplitude height, and the barrel tuner to further dampen , but more importanly to find the positive compensating node ( the node where slow bullets and fast bullets with different exit time do hit the same place on target, especially in vertical). The bullet MUST exit the crown always on rising front, no matter if the best tune if found in a slope or a top. (Never on falling front, this will be the oposite of positive compensation, and actually increase the vertical. This is a good indicator when tuning when you see extreme vertical, that means youre in the wrong place in the tuner range). The bedding must be perfect and a torque setting that is favourable, this must be found, no manufacturers tips will do the trick here. Another thing that can help to furthe dampen the amplitude is a gasket under the action, works for some guns, others not. Torque should be manipulated first while all the other devices is mounted, and tuner in outer most position. Just by manipulating torque, the rifle should be able to shoot round ragged holes. Further from here, position the limbsaver to best position where groups seem to even tighten up and vertical gets lower. Then tuner time. Try the whole tuner range inwards with 1 revolution steps until you see vertical is near zero. When you find the best spot. try go past it until it gets worse to obtain data. Go back and verify with 30 shot groups. 30 shot groups should not be more than 6mm center-center, preferably tighter. (the lot must be selected and high quality ammunition, only the premium line from Lapua, RWS or Eley will do, rest is not consistent enough(it cant be stated clearly enough) , with ammo that is not the best, the positive compensating node will not be strong enough to keep the group together, and you will sooner or later get a high or low shot that is runing score). Shooting rimfire BR is all about consistency over time. Shooting "Not big groups" over time. Forget the small samlple screamer groups, those are just small positive signs. Do shoot 30-50 shot groups, observe that the bullet moves with spindrift effect as it should, and not move to much in the wind. A good tune, is moving minimal in the wind, and a bad tune will move alot more. Just my hard earned advices from benchrest rimfire shooting using some of the best weapons available on the market combined with many houndred hours and ten thousands of rounds experimenting for best possible precision @50 meters benchrest over time. (Tuning should always be done in wind with wind flags(calm day , but with wind), never indoors. A bullet reveals its flaws when affected by the force of wind). A quality barrel with chamber for the exact cartridge you are shooting is important, and a good suited stock. And not to forget the headspace of the bolt must be optimalized to fit the average rim thickness of the selected ammo lot. it is also smart to sort rim thicknesses into batches, too thick, too thin and average. then save the average for competition and tune using a mix of the to thick and the to thin to allocate the most wide node which handles the variations. There you go :) Very cool videos regarding harmonics! But remember, even the measuring devices added to the barrel , will alter the harmonics as well. When you remove them, the barrel will then shoot differently. All mass added/subtracted from a barrel, will do this- more or less. So it is very hard to actually measuring this precisely, alot more easy to just read the target. When you know what to look for, its pretty easy to tune from what you see and observe.
If you look at the rail under the forend under recoil you can see the entire gun move, not just the barrel. The barrel whip is far less than visually perceived
The barrel movement produced from start to crown is the important, what happens after you see the exit gasses emerge(barrel whip)- is not important at all. There is alot on this barrel that is really not needed. All you need (not always) is the limbsaver at correct location to dampen the amplitude height, and the barrel tuner to further dampen , but more importanly to find the positive compensating node ( the node where slow bullets and fast bullets with different exit time do hit the same place on target, especially in vertical). The bullet MUST exit the crown always on rising front, no matter if the best tune if found in a slope or a top. (Never on falling front, this will be the oposite of positive compensation, and actually increase the vertical. This is a good indicator when tuning when you see extreme vertical, that means youre in the wrong place in the tuner range). The bedding must be perfect and a torque setting that is favourable, this must be found, no manufacturers tips will do the trick here. Another thing that can help to furthe dampen the amplitude is a gasket under the action, works for some guns, others not. Torque should be manipulated first while all the other devices is mounted, and tuner in outer most position. Just by manipulating torque, the rifle should be able to shoot round ragged holes. Further from here, position the limbsaver to best position where groups seem to even tighten up and vertical gets lower. Then tuner time. Try the whole tuner range inwards with 1 revolution steps until you see vertical is near zero. When you find the best spot. try go past it until it gets worse to obtain data. Go back and verify with 30 shot groups. 30 shot groups should not be more than 6mm center-center, preferably tighter. (the lot must be selected and high quality ammunition, only the premium line from Lapua, RWS or Eley will do, rest is not consistent enough(it cant be stated clearly enough) , with ammo that is not the best, the positive compensating node will not be strong enough to keep the group together, and you will sooner or later get a high or low shot that is runing score). Shooting rimfire BR is all about consistency over time. Shooting "Not big groups" over time. Forget the small samlple screamer groups, those are just small positive signs. Do shoot 30-50 shot groups, observe that the bullet moves with spindrift effect as it should, and not move to much in the wind. A good tune, is moving minimal in the wind, and a bad tune will move alot more. Just my hard earned advices from benchrest rimfire shooting using some of the best weapons available on the market combined with many houndred hours and ten thousands of rounds experimenting for best possible precision @50 meters benchrest over time. (Tuning should always be done in wind with wind flags(calm day , but with wind), never indoors. A bullet reveals its flaws when affected by the force of wind). A quality barrel with chamber for the exact cartridge you are shooting is important, and a good suited stock. And not to forget the headspace of the bolt must be optimalized to fit the average rim thickness of the selected ammo lot. it is also smart to sort rim thicknesses into batches, too thick, too thin and average. then save the average for competition and tune using a mix of the to thick and the to thin to allocate the most wide node which handles the variations. There you go :) Very cool videos regarding harmonics! But remember, even the measuring devices added to the barrel , will alter the harmonics as well. When you remove them, the barrel will then shoot differently. All mass added/subtracted from a barrel, will do this- more or less. So it is very hard to actually measuring this precisely, alot more easy to just read the target. When you know what to look for, its pretty easy to tune from what you see and observe.
Thanks for your advice.
Very cool !
Thanks. It will be more interesting when I finish designing all the sensors to monitor the barrel harmonics and tune it up.
If you look at the rail under the forend under recoil you can see the entire gun move, not just the barrel. The barrel whip is far less than visually perceived