Guys

This is a new post for several questions that were being discussed in "the next Big thing in PCP's.

The following info is what I have been playing with, for the .172"/.224" Bullets and .177"/.220" Pellets etc.

I don't know the barrel Bore cross sectional area for the 17/22 cal pellet rifles is, so my calculations are off,

as I know the 22 cal pellet and .177 pellet rifle bore area is smaller, than RF/CF bbl Bore X sectional bbl areas/spec's etc.

I used .222" Bore X sectional of the 22 LR RF bbl, of .037293 sq inches.

The .224" CF Bore X sectional barrel area is .03889 sq inches,

and the .172" CF Bore X sectional barrel area is .022859 sq inches.

I hope that Bob will show the correct spec's etc, as he is the AR GURU.

LOL

As I am still in the 1st grade.

I had a choice of which Shot Start (initiation) pressure to use, which is the force required to start the pull out and engraving of the bullet,

so I will post both of the start PSI of "O" PSI and 146 PSI, for both the Bullet and Pellet choices posted.

I used a 3000 psi as Max psi used for all calculations in both caliber examples.

Here is what I came up with for the following Bullets and pellets,

I kept the same standards thru out, ie,

24" bbl length, 3000 psi for pressure,

.220 cal bbl Bore X sectional area of .037293 sq inches, for .220" cal pellets,

.224" CF bbl Bore X sectional barrel area is .03889 sq inches, for .224" Bullets

.172 CF bbl Bore X sectional area of .022859 sq inches, both pellets and bullets.

.172 cal bullet, 20 gr bullet, with a BC of .185 and SD of .097 at of 1000+ fps,

.224 cal bullet, 35 gr bullet, with a BC of .109 and SD of .100 at 1000+ fps,

.220" cal, 29gr Eun Jin Pellet, 24" bbl @ 3000psi, "O" start psi, with a BC of .xxx and SD of .xxx

start ===@ 5" bbl travel==10" bbl travel=15" bbl travel===20" bbl travel===24"

870 fps = 845 fps ======804 fps ====745 fps =======622 fps======0 fps

3000 psi=1058 psi =====493 psi ==== 309 psi ======= 220 psi =====170 psi

Same as above with 146 psi start

856 fps ==831 fps ======791 fps ====713 fps========616 fps =======0 fps

3000 psi ==1006 psi =====477 psi ====299 psi ========215 psi ======164 psi

35 gr VMax .224 Bullet, 24" bbl, @ 3000psi, O start psi, with a BC of .109 and SD of .100

start ===@ 5" bbl travel==10" bbl travel=15" bbl travel===20" bbl travel===24"

870 fps = 845 fps ======804 fps ====745 fps =======622 fps======0 fps

3000 psi=1058 psi =====493 psi ==== 309 psi ======= 220 psi =====170 psi

Same as above with 146 psi start

799 fps ===773 fps ======739 fps ====687 fps========576 fps =======0 fps

3000 psi ==1006 psi =====984 psi ====464 psi ========281 psi ======159 psi

These are SWAG's,

as I am not sure I have the calculator set up right, for PSI values x distance etc.

I will post the 17 pellet/bullet info later, along with the friction reduction coating of bullets/pellets etc.

Thoughts, suggestions or Ideas?

Tia,

Don