Batmancaver Posted November 2, 2006 Report Share Posted November 2, 2006 Hi all Does anyone have any idea why my POI alters as it does? I had a practise session earlier and was managing to get some good results using my S200 and a home made bi-fur pod (http://www.varmintal.com/abifu.htm) as you can see (5 shots per zone). I then swapped to not using the bipod and thought whats happening. Target 02 shows that on the 1st zone that all my shots were below the bull. On the second I swapped back to using the bipod and found that all my shots were basically in the bull. On the 3rd and 4th zone I again did not use the bipod and on the 5th zone I used the bipod again (10 shots per zone). I am resting my S200 on the bipod using the foregrip. In some way is this causing the POI to alter, or is there some other explanation? Answers on a postcard please! Cheers Karl Quote Link to comment Share on other sites More sharing options...
pin Posted November 2, 2006 Report Share Posted November 2, 2006 We'd need to know how your non bi-fur-pod shots were taken... Quote Link to comment Share on other sites More sharing options...
king ratcatcher Posted November 2, 2006 Report Share Posted November 2, 2006 They will be diffrent, my s16 is, i can zero on the bipod, then take the bipod of, then take a few shots, theyle be out, its a conpletely diffrent hold, i know it shouldnt matter with pcp, but it seems to with me Good shooting btw Quote Link to comment Share on other sites More sharing options...
Batmancaver Posted November 2, 2006 Author Report Share Posted November 2, 2006 Hi Pin The shots taken unaided were shot using a sitting stance resting the foregrip in the crook of my left arm resting on my knee. Karl Quote Link to comment Share on other sites More sharing options...
pin Posted November 2, 2006 Report Share Posted November 2, 2006 I'd have said this was to do with your eye position relative to the scope when on the 'pod as opposed to off it. Don't know the range but nice groupings without the 'pod fella!. PCP rifles do have recoil, people call them recoilless but it simply isn't true On a pod as compared to free hold you would see a small difference in POI but I wouldn't have thought it would be that much. Perhaps re-do the experiment with a bench rested shot as well as the 'pod shot and see what happens. This phenomena of POI changing in different positions is much more pronounced in air rifles than it is with say centrefire rifles. Lock time comes into it a little (time between trigger pull and primer ignition), but it is more to do with the speed of the projectile. Centre fire rifles have a reputation for going where you point them, the projectile is out of the barrel in less than 2ms in some cases, not a lot of time for the movement of the barrel after the trigger is pulled for it to make much difference. This effect is multiplied with an air rifle, much more time before the pellet leaves the barrel from the time the trigger was pulled, air rifle shooters have to stay much more still to be accurate Quote Link to comment Share on other sites More sharing options...
rarms Posted November 2, 2006 Report Share Posted November 2, 2006 I am guessing you rested the pod on the cylinder of the gun, this would put all the guns weight on the cylinder and thus push the barrel and cylinder up slightly. Hence higher shots as the barrel is slightly push up When you shot the lower pic you were probably supporting the action using the foregrip which is fixed further back to the action. Quote Link to comment Share on other sites More sharing options...
Theskyfox Posted November 2, 2006 Report Share Posted November 2, 2006 The only input I really have is this....I've noticed that with any air rifles your technique will have the most impact on your shooting (pardon the pun). Once I noticed that by holding my rifle very tight I used to jog on the shot, then I realised to hold it firmly but gently and the pellets hit their target. Basically think of your arms and hands holding the rifle like the mounts between your gun and scope...its needed to make you and the gun work as a single unit efficiently (if that makes sense?). Experiment and see how you get on... -Andrew Quote Link to comment Share on other sites More sharing options...
Lancs Lad Posted November 5, 2006 Report Share Posted November 5, 2006 you have answered your own question... you have shot on a "pod" and without.......... difference is the thing between the gun and your finger............its called you............ Im devastating when podded............... take the pod off and take any other position, prone or sitting and Im not as good...... Quote Link to comment Share on other sites More sharing options...
Batmancaver Posted November 7, 2006 Author Report Share Posted November 7, 2006 Well I did a bit of further testing at the weekend and found out that when I rested the rifle on my pod using the end of the foregrip then my shots were smack on in the bull. However, when I moved the pod till the rifle rested on it just in front of the trigger guard then all of my shots were about 8mm below the bull. Obviously the problem is that the pod is pushing the barrell up slightly so I will now have to investigate whether the same happens when I shoot unaided with the rifle resting on my hand in the two different places. Oh well, back to the plinking range! Karl Quote Link to comment Share on other sites More sharing options...
Lancs Lad Posted November 7, 2006 Report Share Posted November 7, 2006 Well I did a bit of further testing at the weekend and found out that when I rested the rifle on my pod using the end of the foregrip then my shots were smack on in the bull. However, when I moved the pod till the rifle rested on it just in front of the trigger guard then all of my shots were about 8mm below the bull. Obviously the problem is that the pod is pushing the barrell up slightly so I will now have to investigate whether the same happens when I shoot unaided with the rifle resting on my hand in the two different places. Oh well, back to the plinking range! Karl what the F were you resting the pod infront of the trigger guard for................. you think your some form of Yankee soldier firing a AR15 whilst holding onto the mag...... pod it at the front...................rest it at the front if not using the pod............ Quote Link to comment Share on other sites More sharing options...
Batmancaver Posted November 7, 2006 Author Report Share Posted November 7, 2006 No need to be so abrupt Lancs Lad! When using my bi-fur pod normally I rest the rifle on it at the front of the foregrip (as it should be done), but when shooting unaided the rifle foregrip rests on the crook of my elbow just in front of the trigger guard (FT freestyle stance). To try to find out whether the POI was altering because of alteration of the rest point I fired some shots with the bi-fur pod resting at the front of the foregrip. I then moved the bi-fur pod to just in front of the trigger guard to see if the POI altered. Doing it this way meant that I was keeping my eye in the same position to the scope and removing any possibility that it was an altering eye position causing the change in POI. Obviously when out in the field I need to know whether holding the foregrip in different positions is the cause of the altered POI. If I end up resting my rifle on the bi-fur pod using the end of the foregrip and that has a different POI as opposed to when I hold my rifle with a different grip on the foregrip then I need to know, otherwise I will not know where to aim - I am certainly NOT trying to be some sort of gung-ho US soldier! Karl Quote Link to comment Share on other sites More sharing options...
kipper Posted November 7, 2006 Report Share Posted November 7, 2006 Interesting, good to see the diferant techniques and the experamenting. good groups and good work batmancaver. kipper Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.