Hunter Posted January 29, 2009 Report Share Posted January 29, 2009 Okay, I'm going to look like a real idiot asking this :wacko: but if you aim at exactly the same spot on the target, should the round not go through the same hole each time? I mean if the wind stays the same should the bullet not hit the exact same spot? I'm missing something silly arnt I? :blink: This is probably the most honest decent qeustion I have seen in a long time. A very good qeustion which a lot of budding Ballistic newbies like myself can learn from. I will try to explain the factors that affect accuracy, and what makes a consitant group. Accuracy in the world of ballistics is just another word for consistancy. Consistancy as far as groups go, means that you are placing each bullet in the same place with each shot, without having to adjust you POA (Point of Aim). You can could be the worlds best marksman, and still not acheive one hole groups because of the follwing issues that I will attempt to list. Lets imagine you have a gun on a fix tripod bolted to the floor. The gun is bolted to the tripod, and you are shooting at 100m. The first shot is a bull. The second shot however is ne inch high, to the right. Why, if my gun is fixed to a tripod with no human input shooting and inconsistant group? Well the answer is in the wind.. Litterly! The slightest amount of wind pressure on the bullet will cuase a distubance in the bullets areodynamics causing instability. But there are other factors too, plenty of them infact... Are the bullets all the same consistant weight? In our examples case the bullet was a factory moulded bullet shich happened to be lighter by only a fraction due to mould tolerance being out. If the bullet was the same weight as the previous round, sureley it would have a closer trajectory? This depends on other factors. Each bullet (we are talking factory ammunition here) is loaded with a specific weight of powder. This is extremely important in accuracy. The ncrease or decrease in powder weights would affect the elevation POI (Point of Impact) because having mor powder in the cartridge would increase the explosive volume of gas which would increase the muzzel velocity, or speed of the bullet, which in turn reduces the affect of gravity on the bullet causing it to land on the target higher. (Logically the opposit for a reduced weight of powder). ''But why is my gun still not producing one-hole groups''?, well there are other things that can cause group sizes to increase. For instance the 100m target is an outdoor target, and your rifle is a wooden stocked sporting rifle. It is raining heavily. A likely and very common problem here is that the stock of your gun, since becoming drenched in rain, and heated by the barrel from previous shots has begun to expand. Underneath the barrel the stock has begun to expand enough to place pressure on the barrel forcing it upwards with a suprisingly large amount of force. Just a tiny amount of pressure is enough to force your barrel upwards causing the POI to change even if your POA is exactly the same. We could also bring in the factor of barrel Harmonics. This is the radiance of energy shockwaves through the metal matiriel of the barrel istelf each time you fire the gun. Imagine hitting a large sheet of steel with a hammer. Loud eh? this is caused by energy being released from the metal in the form of shockwaves into soundwaves. Soundwaves excluded (we all know guns are loud!) the shockwaves play a big role in accuracy. Left un-interupted, the shockwaves will run their course around the barrel pretty much the same way every time you take the shot. But if your stock begins to apply pressure to the barrel, the course of the shockwaves will be changed, causing the barrel to react differently to the energy being released through it. Imagine slow motion the barrel actually flexing (it does!) due to this energy. So making sure your stock is not touch (and will not) touch the barrel is very important. Sand away the matiriel and get plenty of clearance if you can Make sure the round of ammunition you use are of a consistant quality, this is why many users eventually load their own ammunition. And ensure every shot you make is consistant by using the same or similar methods for each shot. No gun in this world will ever shoot 100% consistant groups, ever. There are just too many factors in Physics that cause inconsistancy. But what makes you a better shot, is to learn what affects your accuracy, and to take advantage of the possibilities to prevent inconsistancy. Its down to you to find out what works best for you, and when you find what works for you, dont stop there. There will always be room for improvement. If in this world it is humanly impossible to acheive 100% accuracy, there is the oppertunity to almost infinatley improve your groups as you learn to comabt the adverse effects of physics on your consistancy. I hope this makes sense? I apologise for any spelling errors Cheers. Quote Link to comment Share on other sites More sharing options...
Dave-G Posted January 29, 2009 Report Share Posted January 29, 2009 Good stuff there - you homeloading anything? Quote Link to comment Share on other sites More sharing options...
Hunter Posted January 29, 2009 Author Report Share Posted January 29, 2009 Somebody actually read it? :wacko: :blink: Not homeloading myself, I shoot a .222 rifle (my Tikka) when I get the chance that is.. and it runs very well off factory loads, the good stuff that is. Im spending about 80-90p a pop, and with the low amount of shots I do (average 1 shot per month, seriously!) I cant justify the investment of reloading gear at the moment. But as soon as I have the the permision and time il be back to shooting again. Lastt time I used the .222 was in August '08, last time I used the .22lr is about 3 weeks ago on a fox call out. I have some forensic experiments comming up which I will be conducting with a Forensics student in a few weeks involving realistic ballistics gel models as part of a university study he is doing, I will run the experiment with him, including building the models. Theres also a few other exciting things lined up such as opening a safe (heavy duty one at that) but I wont spoil the details yet. Hope you are all well, I dont post here much latley as I got a bit put off for a while due to a certain few muppets. But I tend to post when things are stable, I still have a read through about once a day Cheers Quote Link to comment Share on other sites More sharing options...
Dave-G Posted January 29, 2009 Report Share Posted January 29, 2009 Don't let the muppets get you down mate, best just to ignore their posts. Some don't much like what I post - do I sound bothered? :wacko: Quote Link to comment Share on other sites More sharing options...
dogfox Posted January 29, 2009 Report Share Posted January 29, 2009 great info mate, just applied for a .22 and this will help me a great deal! thanks! Quote Link to comment Share on other sites More sharing options...
sirnovember Posted February 1, 2009 Report Share Posted February 1, 2009 Thanks for your response mate. I'm applying for a 22 and a 17HMR, but first I'm going to go on one of those basic rifle course's to put me in good stead. Quote Link to comment Share on other sites More sharing options...
Hunter Posted February 3, 2009 Author Report Share Posted February 3, 2009 To be honest I think I have learnt a lot more about guns from using this forum and meeting the people who use it, then I have from the BASC course. And it was cheaper. You could always do the safety course but I dont know how much you will benifit from the BASC course as I hear its quite basic stuff. If you have qeustions, ask them on this forum, theres a lot of good knowledge here from varius members. Quote Link to comment Share on other sites More sharing options...
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