Does muzzle flip occur when:
1. the pellet is still inside the barrel?
2. the pellet has left the barrel?
Muzzle flip will occur the moment the pellet starts moving in the barrel. Your shoulder is the anchor for the gun so when it starts to move back it meets resistance and thus will start to pivot upwards(the energy has to go somewhere) hence muzzle flip.
A very interesting thing is that sometimes a rifle is zeroed with a light bullet then when you switch to a HEAVIER bullet the POI is higher! This is because the heavier bullet stays in the barrel slightly longer and the barrel is moving upwards because of the recoil.
You are right, flip uccurs the moment the pellet starts moving.....
For a visual demo, look at http://www.arld1.com/images/swfs/rif...icssmaller.swf
The principle of a heavier pellet striking higher than a lighter pellet is also clearly illustrated here.... Obviously this is measured close to the firing point, before the heavier pellet has lost too much speed.....
I have noticed this within the first 10m or so when using light (8,44g) and heavy (10.35g) JSB's.....
Recoil is the backward movement of the rifle upon firing. If the gun does not get any resistance it will move just straight backwards (think recoilles rifles....I miss my 54) since this will be the obvious opposite reaction to the firing cycle (every action has opposite reaction) BUT the gun DOES meet resistance when moving backwards (your shoulder!) and from there it must go somewhere to complete the shedding of energy (from the firing of the gun) and thus the easiest route is upwards thus muzzle flip. The moer power the gun has the move backwards movement and the more resistance on your shoulder and the more muzzle flip. A 4 bore guns muzzle will flip almost 90 degrees when fired. Eina
Pre-charged airguns briefly act like rockets on discharge and it's called the "rocket effect" and causes the muzzle to lift. The only totally recoiless PCP is the Steyr LG-100 and 110 which is fitted with a stabilizing anti-recoil device-a weight, propelled in the opposite direction to the pellet as it is fired. Spring rifles on the other hand, well the recoil and subsequent muzzle flip produced is mainly mainly due to the movement of the large and powerful spring and piston which mainly dictates how the rifle behaves, over-riding any other component in the firing cycle. The only movement on a PCP is of the hammer striking the valve or regulator to release the high pressure air, propelling the pellet down the barrel. When dealing with 12ft/lb airguns, if the valving system or regulator is efficient -meaning that there's very little surplus and wasted air behind the pellet - then the muzzle will hardly flip. The opposite hold true for an inefficient PCP.
Some very good descriptions as to this phenomena were posted.
I found Falcon"s description spot on except that the last time I spoke to the German manufacturers they only fitted the anti-recoil system to the 10m 6fpe rifles---that included Steyr....explanation being that the higher energy guns did not respond positively with these devices fitted.
As I stand to be corrected I have sent them a new enquiry.
Furthermore and I discussed this with Harry Preston the UK Steyr agent two years ago short barrels recoiled more and this was the only criticism he had heard of regarding the 110. FT.
I attached an accelorometer to a few of the rifles in that period and had to concur that shorter barrels reacted more when fired than longer barrels... mass being equal.
As soon as I hear from them I will post their response.