TargetTalk

Hello Friends:

I am amazed at the knowledge of everyone here. Simply amazing. Don't post much as I am not at a level worth posting.

I have 2 questions I thought to ask:

What is the cylinder volume for a Feinwerkbau 800 Field Target gun and...
similarly, what is the cylinder volume for a Feinwerkbau P44 pistol (not short barrel).

I cannot find the answer anywhere.

Appreciate it.

Volume should be engraved on tank.
Similar tank size (same shot numbers) is the Morini 162 at 0.08 litre

My P44 tanks do not have a volume engraved on them.

Presuming that the tank is cylindrical, you may calculate a rough estimate.

Measure the length of the tank (L).
Measure the diameter of the tank (d).
The outside volume of the tank is then Vo = L*3.14*(d/2)^2.
If we guestimate that the volume for air is 10% less than the outside volume, then the air volume V = 0.9*Vo.
If your measurements were in millimeters, the volume is now in cubic millimeters.
In liters the final volume is Vl = V/1000000, in cubic centimeters it's Vc = V/1000.

An example: let's say you get L = 150 mm, d = 30 mm.
Vo = (150 mm)*3.14*((30 mm)/2)^2 = 105975 mm^3
V = 0.9*105975 mm^3 = 95377.5 mm^3
Vl = 0.095 L
Vc = 95 cm^3

Well I want to know the volume when the cylinder is filled to 2900 psi = 200 bar.
Since air is being pressurized, it will contain more volume than at 14.7 psi = 1 atmosphere.

Maybe I should be using Boyle's Law.

David M wrote: ↑Mon Oct 18, 2021 2:35 am Volume should be engraved on tank.
Similar tank size (same shot numbers) is the Morini 162 at 0.08 litre

I'll look.

I'm a little confused by your question. Your concern should be the number of shots per fill, which will drop after every fill.

Mr. Wonderful wrote: ↑Mon Oct 18, 2021 4:58 pm Well I want to know the volume when the cylinder is filled to 2900 psi = 200 bar.
Since air is being pressurized, it will contain more volume than at 14.7 psi = 1 atmosphere.

Maybe I should be using Boyle's Law.

It's as simple as 200 * original volume since you are correct in using Boyle's Law P1V1=P2V2. Solved for V1 (the volume you have to compress to get 200 BAR) you get (200 BAR * 0.08l)/1BAR = 16l

(I borrowed the cylinder size of 0.08l from another thread and it seems to closely match the measured dimensions of my Steyr LP10 cylinder.)

Mr. Wonderful wrote: ↑Mon Oct 18, 2021 4:58 pm Well I want to know the volume when the cylinder is filled to 2900 psi = 200 bar.
Since air is being pressurized, it will contain more volume than at 14.7 psi = 1 atmosphere.

Volume of Morini 162 tank at 15 C and 1013.2mb
Sea level 0.08 litre
80 bar (empty non firing) 6.31 litre
200 bar Full 15.78 litre

Rover wrote: ↑Mon Oct 18, 2021 9:17 pm I'm a little confused by your question. Your concern should be the number of shots per fill, which will drop after every fill.

I am a scuba diver with multiple scuba tanks of varying volume. Example: I have a 100 cu ft tank at 3400 psi when full. Also have a 80 cu ft tank with a top pressure of 3500 psi. Each tank psi will decrease with filling my rifles but instead of calculating pressures, its better to do so with volume.

Green_Canoe wrote: ↑Mon Oct 18, 2021 9:26 pm

Mr. Wonderful wrote: ↑Mon Oct 18, 2021 4:58 pm Well I want to know the volume when the cylinder is filled to 2900 psi = 200 bar.
Since air is being pressurized, it will contain more volume than at 14.7 psi = 1 atmosphere.

Maybe I should be using Boyle's Law.

It's as simple as 200 * original volume since you are correct in using Boyle's Law P1V1=P2V2. Solved for V1 (the volume you have to compress to get 200 BAR) you get (200 BAR * 0.08l)/1BAR = 16l

(I borrowed the cylinder size of 0.08l from another thread and it seems to closely match the measured dimensions of my Steyr LP10 cylinder.)

Thank you.

And in any case someone wondered, I have written to FWB and came back with no answers.

To determine the volume of a cylinder filled with air at different pressures, you can use Boyle's Law, which states that the pressure of a given amount of gas is inversely proportional to its volume at constant temperature. The formula for Boyle's Law is: � 1 ⋅ � 1 = � 2 ⋅ � 2 P 1 ​ ⋅V 1 ​ =P 2 ​ ⋅V 2 ​

where: � 1 P 1 ​ is the initial pressure, � 1 V 1 ​ is the initial volume, � 2 P 2 ​ is the final pressure, � 2 V 2 ​ is the final volume. Given that the initial pressure is 14.7 psi (1 atmosphere) and the final pressure is 2900 psi (200 bar), we can set up the equation: 14.7 ⋅ � 1 = 2900 ⋅ � 2 14.7⋅V 1 ​ =2900⋅V 2 ​ Now, to find the relationship between � 1 V 1 ​ and � 2 V 2 ​ (the volume at 1 atmosphere and 200 bar, respectively), we can rearrange the equation: � 1 = 2900 14.7 ⋅ � 2 V 1 ​ = 14.7 2900 ​ ⋅V 2 ​ This tells us that the initial volume ( � 1 V 1 ​ ) is equal to the ratio of the final pressure to the initial pressure multiplied by the final volume ( � 2 V 2 ​ ).