Originally Posted by maestro
So what do you think about my first picture mate? Is that a free floating barrel? It comes out of the block, doesn't it?
To be honest, I don't give a shhh how it's called, free floated or 'supported semi-floated thingy á la maestro'
. But I do claim that the A-clamp is more likely a part of the breech block (because it is, in the mechanical scheme). And as these two hinged supports, the A-clamp and the breech block, are not too far from each other, they act as one massive fixed support and the barrel is totally free after this - so if it looks like a duck, sound like a duck, and acts like a duck what is it?
And don't forget that we want the free floating not for itself. We want that the scope body and the barrel end look always in the same direction, because in this case the POI shift is only a history. And to achieve this, we have to meet two very simple criteria: the scope has to be mounted as directly on the barrel as possible, and the barrel must not receive any other forces after this mounting point. This means in the practice that scope and barrel must be supported on the same two points
(at the two AA signs on my picture) and nowhere else
. And name this system as you want to
Also a case of a/ isolation of external forces and b/ ensuring system harmonics are consistant.
a/ As pressure increases or decreases in the air cylinder this can exert an influence on the allignment of the barrel, temperature also can have this effect, especially in cases of dissimilar materials or discreet parts.
b/ As a rifle fires this induces a number of frequencies in the system (i.e. the resonant frequency and harmonics of this frequency) if the barrel is supported at one point it is free to resonate at its resonant frequency and will do at exactly the same frequency and amplitude each time. However if the barrel is supported at both ends, and the nature of this support changes, this can change RF and amplitude of the barrel leading to POI shifts due to say temperature or changes in the air cylinder.