Number of high pressure fills from a 90 c.f. carbon fiber tank

I am hoping to enter the PCP world of air gunning shortly. I live about a 15 minute drive from a dive shop that can charge any 4,500 psi tank I would purchase. I know a new carbon fiber tank of 90 cu. ft. would go for about $700. Perhaps I could save a bit by purchasing such a tank used with perhaps 5 or so years left on its life. I am 78 years old and continue to receive chemotherapy every other week. This has been going on for three years, since the removal of my stomach, spleen, and the tail end of my pancreas. Yes, I have new "plumbing". My weight currently has stabilized in the 120's. That after weighing in the low 190's before the surgery. My recent and past PET scans show the therapy has things under control, thus far. I just had my bi-weekly infusion yesterday. It leaves me feeling not so good for two or three days. Overall I have tolerated the therapy regime quite well. I guess I am one of cancer center's "success stories". I live alone in a manufactured home in a park. I have been a widower for nearly 16 years. My son and daughter live nearby, as well as my daughter's son, and I have a church family that cares about me. After a long hiatus, our church will meet in the pavilion behind the church this Sunday!

I would like to give this hobby/sport a try. I have no "back yard" in which to shoot. I know someone that has a large property who lives only about ten minutes away, so I will be asking him if I could set up a portable bench and shoot there. My grandson says he has shot both a pellet rifle and a .22 rimfire on the property. I was into power burners in earlier days, beginning in the Air Force where I was a member of my base's high power rifle team. The anti-gunners are so ignorant. I don't say that as a put down, but simply meaning they are uninformed. As a member of a military team we shot along side civilian men that were doctors and lawyers when shooting at the rifle club where we competed, about 400 miles from the base. I know there are yahoos out there who give shooting firearms a bad name, but the serious competitor is of another stripe. They were men and women who were friendly and enjoyed the opportunity to compete and improve their skills.

I am considering purchasing one of the new Air Venturi Avenger rifles that can be charged to 300 bar. The man at the dive shop said I could purchase a new 106 cu. ft., 4,350 psi carbon fiber tank for $480. If I wanted to charge this new 300 bar rifle with the 4,350 psi tank, would there be a significant difference in the ability to charge the rifle to 300 bar, compared to a 4,500 psi tank? As you charge an air rifle to 300 bar from the tank, does the tank stop giving full 300 bar charges as its air supply is depleted? I wish to thank you in advance for your kind replies. Don't feel sorry about my health situation. It has never caused me to be depressed. I look forward with yearning for a blissful eternity! God bless each and every one of you, and I thank you for this forum which allows me to gain knowledge about the equipment I might want. I only wish I could actually handle different rifles before making a purchase. I would like to be able to hunt our Pennsylvania groundhogs once again, just at a much shorter range than I could with my 22-250 custom rifle of yore. I had a fixed 20 power scope on it. I am considering the Aim Sports Alpha 6 4.5-27x50 scope mentioned by "YO" for this new rifle. Before that, I was considering an Athlon Midas Tac 6-24x50. For close range work the 4.5 power would seem a better choice, and the slight increase in maximum power might enable me to see pellet/slug holes on 100 yard targets a bit better. I am sure this will be my last rifle and scope purchase. I cannot roll the clock back to where I was a "youngster" in his or her 30's or 40's! So, I have waited a long time to make my decisions -- but it's getting late and the fair weather will soon be gone, as is my "sweet bird of youth. I look forward to Steve's (AEAC) full review of the Avenger rifle, as I am sure many of you are doing also. The rifle does not have a high-capacity bottle, but takes advantage of the 300 bar fill. If it shoots well at 50 & 100 yards from its uncrowned barrel, they will have a winner. I could shoot lighter, less expensive, pellets while allowing my 24-year-old grandson and his friends an introduction to these remarkable inventions, and then use the full power for a heavier pellet or slug (lots of testing to do!) for hunting those groundhogs, or whatever. Pardon my rambling back and forth in what I have written. I should have made a google document and printed it out and done proper editing. Once again, I thank you all.
 
http://www.calc.sikes.us/2/ Fill in the blanks and you will know how many fills you will get. 

As you charge an air rifle to 300 bar from the tank, does the tank stop giving full 300 bar charges as its air supply is depleted? You are not going to be getting 300 bar fills. You might get close the first few fills, but once the pressure in the 100 cf tank decreases, you can only fill the tank you are charging to a similar pressure. This being said I would use 250 bar (3625 psi) as the "fill gun to number" when you use the tank fill calculator.
 
Hi Mr Wannabee,

There are a lot of us out here getting a few years on us who are simply grateful for all that the good Lord has given us, all that He has taken away and all that He has left us. My attitude is that it's all in his hands ... I'm not gonna live one second more or one second less than He wants me to ... so why worry, simply enjoy the grace that the Lord freely gives to each of us and count it as another of the many wonderful blessing He continues to bestow on this wretched old man. God is perfect, it's not an aspiration that He has, He doesn't try to be perfect, that's simply who He is ... and He can be no less than who and what He is. 

I have a Cricket pcp that I can fill to 300 Bar. I seldom do because I feel like that much pressure is a little hard on the o-rings. The gun is regulated so it doesn't give me more velocity on the pellet by going all the way to 300 Bar. If I were you, I would simply fill to between 250 or 260 Bar. That way you will take it easier on your gun. When dealing with high pressure air the o-rings are usually the weakest spot on the whole system.

The carbon fiber bottle is most likely a 4500 psi rated bottle that the dive shop doesn't want to fill beyond 4,350 psi. A lot of dive shops are like that, they give themselves a little leeway when filling to those kind of pressures. When filling the air reservoir on your gun, unless you have have done this before or you have a slo-fill valve on your tank, be extremely careful when filling your gun. That air can come out faster than you ever thought possible and if you fill too fast, you can damage the gun also.

As your air supply in the cf bottle goes down, you can still keep filling your gun to the point where the pressure in the tank reaches the point that the gun is regulated at. In other words, if your gun is regulated at 150 Bar, you could run the bottle down to 150Bar also ... but you would not get many regulated shots. Most of us who have been blessed to have a compressor let out cf tanks go down to about 3000 PSI (which is about 210 Bar) and then we charge them up again to anywhere between 4200 - 4500 PSI.

Not to worry about the rambling, you are an interesting man with a lot of history behind you. May God continue to bless you richly through all the ups and downs of life and I look forward to meeting you someday when hope and faith become reality.

If I can be of any help along the way, just drop me a PM and I'll try to get back to you

Shalom

John


 
Hi Mr Wannabee,

There are a lot of us out here getting a few years on us who are simply grateful for all that the good Lord has given us, all that He has taken away and all that He has left us. My attitude is that it's all in his hands ... I'm not gonna live one second more or one second less than He wants me to ... so why worry, simply enjoy the grace that the Lord freely gives to each of us and count it as another of the many wonderful blessing He continues to bestow on this wretched old man. God is perfect, it's not an aspiration that He has, He doesn't try to be perfect, that's simply who He is ... and He can be no less than who and what He is. 

I have a Cricket pcp that I can fill to 300 Bar. I seldom do because I feel like that much pressure is a little hard on the o-rings. The gun is regulated so it doesn't give me more velocity on the pellet by going all the way to 300 Bar. If I were you, I would simply fill to between 250 or 260 Bar. That way you will take it easier on your gun. When dealing with high pressure air the o-rings are usually the weakest spot on the whole system.

The carbon fiber bottle is most likely a 4500 psi rated bottle that the dive shop doesn't want to fill beyond 4,350 psi. A lot of dive shops are like that, they give themselves a little leeway when filling to those kind of pressures. When filling the air reservoir on your gun, unless you have have done this before or you have a slo-fill valve on your tank, be extremely careful when filling your gun. That air can come out faster than you ever thought possible and if you fill too fast, you can damage the gun also.

As your air supply in the cf bottle goes down, you can still keep filling your gun to the point where the pressure in the tank reaches the point that the gun is regulated at. In other words, if your gun is regulated at 150 Bar, you could run the bottle down to 150Bar also ... but you would not get many regulated shots. Most of us who have been blessed to have a compressor let out cf tanks go down to about 3000 PSI (which is about 210 Bar) and then we charge them up again to anywhere between 4200 - 4500 PSI.

Not to worry about the rambling, you are an interesting man with a lot of history behind you. May God continue to bless you richly through all the ups and downs of life and I look forward to meeting you someday when hope and faith become reality.

If I can be of any help along the way, just drop me a PM and I'll try to get back to you

Shalom

John


Great attitude