Indians For Guns

Why when we increase the muzzle velocity of a given springer even by few fps than its limit the accuracy goes wayward?

Answer is provided by the laws of ballistic physics. For exact answer may search the text books of physics or internet websites dealing with ballistics. Just a rough idea, when you increase the muzzle velocity of springer, two things are likely to happen, vibration increases within the barrel and there can also be increase of air turbulence around the pellet. Heavier projectiles are less affected by air turbulence.

Yes dear,in my opinion though it may be wrong,when we increase the velocity the blast of air which the pellet skirt recieve from transfer port make the pellet slip in high speed instead of engaging in rifling.Thus it doesn't receive the necessary circular movement along its path.

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This very thing is boggling me since I started this hobby and hope will get right information from dear members.

How do you increase the velocity of springer? By increasing the strength of the spring? If yes, then won't the piston hit harder at the end of compression tube? If yes, will it not cause more vibrations or rather vibrations at a different frequency in the compression tube and the same getting transferred to the barrel. A randomly vibrating compression tube and further randomly vibrating barrel can never be good for accuracy.

If you had done in school or college days, the experiments with tuning fork, probably it would be easier for you to understand. Compression tube has it's own fundamental frequency and harmonic frequencies. Similarly the barrel has it's own fundamental frequency and harmonic frequencies. When you make changes to the strength of the spring, don't the harmonic frequencies get disturbed to cause random or irregular vibrations?

This physics principle related to harmonics of the gun and it's barrel applies to all types of guns. That is why you might have heard the term "rifle tuning". You may read this link related to rifle tuning http://www.snipercountry.com/Articles/RifleTuning.asp

Dear Target point, one of the proven ways in which you can ensure better pellet behaviour (more behaved or accurate) in ARs with enhanced MV is by using low start pressure pellets. They not only expand early (the skirt that is) and engage better with the barrel rifling, but necessarily also ensure longer cylinder pulse.....all resulting in supplementing MV as well as taming the AR's surge (which eventually gonna be higher when you increase power). The only thing you may have to live with is a longer and more intense recoil. However, that would be so small (say, in the range of one-tenth of a mm) that most will fail to notice.
In our Indian context, I have experienced that the better behaviour of United Shot pellets (most of their recent variants) is primarily owing to these being low start pressure ones.

@ Goodboy_mentor, a harder spring may be just one of the ways of increasing power. In fact, this is the least preferred one, and also the one whose results are often to the contrary. There are ample of experiences to substantiate this even on this forum. Also, Laws of physics acting on AR mechanics sadly become so complicated (because several of them -compressible fluid dynamics and thermodynamics equations arising from high pressure and temp at play during the short shot cycle are at work at the same fraction of time) that there are no easy answers to the way ARs behave.
Regards,
Prashant