Supersonic Air?

Hello All,

I have been tuning my Liberty and came across a question about the sound barrier. I noticed a big increase in the sound level at a certain point of power output. I am pushing 21.14 H & N pellets a little bit over 800 FPS. which is well below the 1,125 FPS. speed of sound but how fast is the air that is pushing that pellet moving. If I was to switch to a much lighter pellet I would be able to break the sound barrier easily. My question is do I have to stay below the threshold of sound for my air speed as well as my pellet speed?

Thank you,

Jim
 
Jim,

A BIG rule of thumb in airgunning is - Faster Is Not Always Better!

When tuning, you'll have to figure out what you're going for ahead of time..
Things like how far do you want to shoot, what you'll be shooting at, and, what pellet you'll be using..
It's best to find out what pellet shoots the best out of your barrel, and then go from there when doing the tune..

Projectile shape, weight, etc. will effect the trajectory..

Most times, a pellet needs a certain 'window' of air power and feet per second in order to be Most Efficient.

So.. Too slow - no good. Right in the middle - Perfect.. Too fast - also no good. 
Throwing a pellet down range too fast will make it become unstable. [That distance can also very]

With my Nova Freedom I didn't mess with the hammer spring at all.. I just use the reg-adjuster..
Low for light pellets and High for heavy pellets.

Roughly 700fps / 900fps

Low I use Crosman Premier 14 gr 
High I used HSB 18 gr - and may also try H&N 21 gr 

Mine shoots great, so, I don't mess with it.

There's a lot of speed-hype when it comes to the industry, and you just need to put that out of mind..
You're Tune is more or less to either give you the best accuracy from point a to point b, 
or, the best overall shot count - per air/tank fill..

The more power / faster fps - the less shots you'll get.
The less power / slower fps - the more shots you'll get. 

Tuning will give you one or the other - or - help you find a happy in between.

🙂👍 

Sam - 

 
Jim,

Welcome! After re-reading your initial post,
I thought that maybe I had just rambled on and on about something else.. 
If you took 'anything' away from all of that - Awesome! 😃 

As for any issues..

I have the Freedom - Not the Liberty, so my model isn't regulated.. 
My only option is to adjust the hammer spring [then the low / high port dial adjustment] 

Even thought I don't have the Liberty [Yet] I still like to follow information pertaining to it.. 
If you haven't caught it yet, Air Velocity Sport is a fantastic source for them:

https://www.youtube.com/channel/UCGPuLw4384KuLzSkGSWLs2Q/videos 

🙂 

Sam -