.177 v .22 shot count ??

FatSteve69

FatSteve69

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Sorry,
could you tell me the reason why 22 gives more shots than 177 [ PCP or CO2 ] ??
Novice thinking is SAME POWER.......SAME SHOT COUNT ?!?!
In laymans terms if possible 🤯
 
FatSteve69 said:
Sorry,
could you tell me the reason why 22 gives more shots than 177 [ PCP or CO2 ] ??
Novice thinking is SAME POWER.......SAME SHOT COUNT ?!?!
In laymans terms if possible 🤯
Click to expand...
It's really all down to muzzle energy and how it's worked out
the calculation is MV X MV X Pellet weight, divided by 450240 = Muzzle Energy (ftlbs)

Assuming that you're comparing rifles in both calibres, with equal muzzle energy
A .177 pellet (being generally lighter than a .22) needs more air to achieve a velocity that will make the same muzzle energy as the .22

to explain it further and possibly simpler
A 7.87g, .177 pellet traveling at 620fps, only achieves around 6.5ftlb
A 13.43g, .22 pellet travelling at the same 620fps, will make approx 11.5ftlb
The factors that apply are pellet weight and muzzle velocity, so to make the lighter pellet travel faster, (in this case around 810fps) to achieve 11.5ftlb, much more air is needed
 
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I always thought it was something to do with the size of the bore, and the relative proportion of air experiencing friction on the edges of the barrel compared to the relative proportion of "free" air in the middle. Basically, there's relatively more friction, and therefore energy loss, in a narrower bore?
 
The easiest equation to think of it is the old school boy F=M x A

Force = mass x acceleration

Since a .22 has higher mass, it needs less acceleration to achieve the same force.

So as mentioned above, the 177 needs to be accelerated up to a higher speed, which needs more air 👍
 
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Taking weight out of the equation, a Leshiy Classic tuned for .25 cal, 16 grain pellet will be more efficient than a .22, 16 grain pellet & that same .22 will be more efficient than a .177 cal, 16 grain pellet.

I don't have the numbers available but I believe it was most pronounced from .177 to .22.

Pellets were GTO lead free, 22 were a JSB or Polymag & the 177 were JSB Beasts. Not all exactly the same weight but close enough.
 
2506sendero said:
Were they any good?
Click to expand...

Unfortunately they were very accurate. I've heard up to 40 yards but I don't recall taking them past 25.

I say unfortunately because they are so expensive.

One of my used Classics came with some extra .22 GTO lead free & the previous owner had already found them to be very accurate. I was so impressed I tried the .25. Same results.

I'm in the US & am not restricted to any power level. I don't recall which power levels I tried but I certainly got below 15 FPE in both .22 & .25. My recollection is no obvious change in accuracy with power.

I don't have any reason to shoot lead free & if anything would worry more about pass through & ricochet. So due to that & the cost I didn't continue shooting them.
 
FatSteve69 said:
Sorry,
could you tell me the reason why 22 gives more shots than 177 [ PCP or CO2 ] ??
Novice thinking is SAME POWER.......SAME SHOT COUNT ?!?!
In laymans terms if possible 🤯
Click to expand...

chouchin66 said:
A bigger sail catches more wind.
Click to expand...

As Chris so succinctly puts it: the 0.22" has a larger surface area 3.142 x 0.11 X 0.11 = 0.038 sq/in
Vs the 0.177"
3.142 x 0.0885 x 0.0885 = 0.0246 sq/in.

This means that the 0.177" pellet has less than 65% of the area of the 0.22" for the air to push against.
This makes the 0.22" more efficient and means that it can be set to use less air to achieve the same muzzle energy as the 0.177".
Therefore the same size reservoir of air will give a higher shot count of 0.22" over 0.177".
 
Another easy way to think of it is blowing through a tube.

It's extremely easy to blow through a toilet roll, but more difficult to blow through a thin straw.

This is mainly an issue with .177 springers, as if they can't 'vent' all the air before the piston hits the back of the compressed air, the air itself acts like a spring and the piston can then bounce back. The tuning is all about trying to get the piston range/speed in sync with the compression tubes 'emptying'. It's a lot more complicated than I fully understand, but this is the way I understand it.
 
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