I wanted to see super slow motion videos of a fixed action rifle in recoil/muzzle rise, because of this thread:

https://sigforum.com/eve/forums...0601935/m/2850093474

But I ended up fascinated by everything involved with the dynamics of firing these cannons. Its a long but interesting video:

https://www.youtube.com/watch?v=MgqIWDPMALk <----- important part starts around 2:53/13:38

I just can't see effects of recoil until the mass of gas, powder and projectile leave the barrel.

So how can recoil be consistently affecting the variation in elevation of POI based on the velocity of the load?

Maybe the answer is in what happens that is too small to see, and not just recoil, but barrel harmonics:


Here is a video of a fixed action firearm with comments about what happens and when it happens, and how this affects POI, with text comments about what we can see and not see:

https://www.youtube.com/watch?v=fbuaH6D2Qgc

While spring piston airguns have mechanical events much different than firearms, look how much barrel harmonics are in effect before these pellets and compressed air leave the muzzle:

https://www.youtube.com/watch?v=OYm_tI7mbBw

quote:

Originally posted by RichardC:
While spring piston airguns have mechanical events much different than firearms, look how much barrel harmonics are in effect before these pellets and compressed air leave the muzzle:

Thanks. I would have never guessed.

There are terms like barrel whip that are used to discribe what happens when you fire a rifle, but I think the term harmonics better describes what's actually happening. If barrels didn't move during the firing of the rifle, all you would have to do is lock the rifle in a vice and all your shots would go through the same hole in the target. Since this usually doesn't happen, I have to assume something is disturbing the flight of the bullet, or something is happening to the rifle to alter the position of the muzzle from shot to shot.

It's this 'something' that products like the accu strut, BOSS-CR, and various barrel tuners try to modulate so the rifle reacts the same way every time it's fired. It's the reason barrels are free floated, and the reason you don't rest the barrel of your rifle on anything when you are firing it.

The airgun video clearly illustrates why they make airgun optics. Spring loaded airguns are known for destroying high end rifle optics. The SCAR-17 had the same problem until they figured out the whole recoil impulse issue.

Guys who shoot long range black powder cartridge rifles off cross sticks will learn where the null point is on their barrel, the spot they can place the sticks and not effect the accuracy. Mark it and always have them in that same spot.