Thanks for those numbers!
They put meat on the plate of decision making.
So, let me interpret and summarize —
within my own parameters —
and in the
units of measure common on AGN: FPE and fps —
in order of lowest to highest power:
Presupposition Air Pressure: My doll-house compressor only gets up to
300bar = 4350psi.
So, I'll need to take off the first seven shots.
Presupposition MV Extreme Spread: I have decided that in a close to midrange pistol I can live with a
shot velocity variation of 35fps over the shot string. That means:
Chart 1: 13.5FPE Tune highest value: 199 m/s = 653fps
(Calc.: 653 — 35fps cut-off = 618fps = 188 m/s)
➔ All but shot No. 60 are within this bracket (653—618fps).
So, with a tune of 12.7—14.2FPE, I get 52 shots from a 300bar reservoir. (Calc.: 60 — 7 — 1 = 52)
Chart 3: 15.3FPE Tune highest MV: 212 m/s = 696fps
lowest MV cut off for me: 651fps
(Calc.: 696 — 35 = 661fps = 202 m/s)
➔ Up and including shot no. 38 are within that bracket.
So, with a tune of 14.5—16.1FPE, I get 31 shots from a 300bar reservoir. (Calc.: 38 — 7 = 31)
Chart 2: 16.5FPE Tune highest MV: 221 m/s = 725fps
lowest MV cut off for me: 690fps
(Calc.: 725 — 35 = 690fps = 210 m/s)
➔ Shot 1—32 are within that bracket.
So, with a tune of 15.9—17.5FPE, I get 25 shots from a 300bar reservoir. (Calc.: 32 — 7 = 25)
Presupposition Test Projectile: I suppose a
high quality PCP uses high quality projectiles.
And I suppose
most users will use pellets rather than slugs.
Now, I went through my list of quality .22 pellets and could not find one that weighs
15 grains even —
as the test projectile in the three charts. Cf. my own
Pellet BC Table attached below.
➠ What was the test projectile....?
Summary 13.5FPE
* ➔ 52 shots
gain 1.8FPE = loose 21 shots:
15.3FPE ➔ 31 shots
gain 1.2FPE = loose 6 shots:
16.5FPE ➔ 25 shots
*About these power levels —— just remember: Our airgun brothers in the UK shoot with less power (sub-12FPE), and they kill rabbits and pigeons at 40 yards, and do an awesome job at field target out to 55y.
What do you think?
Matthias
Attachment: Pellet BC Table .22cal
View attachment PELLETS. BC Table .22cal.pdf