TargetTalk

Never give up

It sounds like there are two valid concerns with a pump and none with the tank if there is a dive shop within reasonable distance. Tank sounds like the easy winner.

I do have a dive shop relatively close. A tank is the safest bet given my circumstances. The dive shop will not fill less than a 75 cu. ft. tanks.

Most of the reviews I read recommended a carbon fiber tank rather than a SCUBA tank. The reason is a SCUBA tank can be filled to just 3000 psi. The cylinders on the air guns I’m looking at are also 3000 psi. This means that after the first fill, I would never be able to completely fill the air gun to 3000 psi again. After each fill of the air gun, each subsequent max fill would be less and less.

Carbon fiber tanks are rated at 4500 psi and would not have this effect until the pressure in the carbon fiber tank reached the 3000 psi level. Based on calculators I’ve seen, topping off a less than 100 cc cylinder when it reaches 2000 psi back to 3000 psi can be done over 100 times with a 75 cu. ft. carbon fiber tank. Even if I got conservatively only 100 shots per fill, that’s over 10,000 shots before I reached where I’d start with a SCUBA Tank.

This all sounds great except a Carbon Fiber Tank costs over 2 ½ times as much as a SCUBA tank. Is it worth it? Is the SCUBA Tank’s 3000 psi limit a practical issue?

I participate in three other forums mostly relating to reloading. Often new posters ask questions which to the experienced sound obvious or naive. This question is equivalent to what reloading press should I buy. I’m sure some of you feel that way with my questions. I appreciate your patience, but I think I’ve learned a lot even in the short time I’ve been here. I know when I make my final choices, they will be informed ones.

Thanks

My shooting range gets big air tanks filled at 200 (they look like the ones used in construction sites) and they go down as we fill our pistols, but stay for many days before being changed. They are picked up and substituted by new ones by the company that fills them.

You don't need to fill at capacity every time to be able to shoot more than a match. We often have to fill the pistol cylinders at about 150 and I can still shoot 120 shots.

What other clubs do is to have a compressor and fill smaller scuba tanks more regularly.

Interesting is it not when you start to know something about what you want you soon learn there is so much more you need to know.

Here is an example of air use:
My Morini fills to 200 bar, as do my steyrs but my pardini fills to 250 bar, I and most others use 300 bar cylinders and fill carefully so as not to over fill - let the air go in very slowly, you will need one of these adaptors to act as a spacer along with the fill adaptor for the pistol.

https://www.bestfittings.co.uk/shop/air ... lid-brass/

My main cylinder is a full size dive bottle and I shoot twice a week at the club 80 - 100 shots each session and never need to swap cylinders except in the summer when I will be shooting the LP50 outdoors doing std and sport pistol and change after 30 shots, as the air is used to work the cocking and magazine movement. Added to club shooing I'm also out at competitions once and maybe twice a month (10m and 10m and 25m in the summer). If a few of us are going to a comp from the club I take my small air bottle just in case someone has forgotten to fill their pistol or rifle. The large cylinder lasts well over a year and possibly two before a recharge but when I was using the small cylinder as my main cylinder that lasted about 9 months but my daughter was filling her full power rifle (12ftlb) from it too.

I have a 100 cubic foot dive tank. I use it a lot and low air has never been a problem. Of course, when I get low I can take it to my club to refill it. I think your concerns about low air are groundless, so just buy the tank (Craigslist for cheap).

Another option is to have a large tank of nitrogen delivered. When it's low, they will exchange it for a full one.

The safety concern with a carbon fiber tank got my attention.

The importance of safety in reloading cannot be overstated. At the least your expensive gun can be damaged, and at worst you can lose your life. One of the most dangerous situations is a double charge. A double charge parallels filling a 3000 psi cylinder with 4500 psi of air. A SCUBA tank seems to eliminate that concern at the small cost of less fills, or incomplete fills, per tank. It’s a small price to pay for added safety. Thank You for pointing this out.

I’m sure I could carefully manage a carbon fiber tank if I had to. I loaded tens of thousands of rounds of ammunition so far without incident. But I know others, firsthand, that weren’t as lucky. I’ve learned to be very careful. But if I can eliminate a major risk, especially at lower cost, so much the better.

In reloading there are manuals that tell you what components to buy, exactly what equipment is needed and how to set everything up. Step by step instructions exist even to the smallest detail. A lot to learn but it’s all available even in kit form. That is not the case here since we are integrating components that were not specifically designed for air gunning.

Where can I find a source that has the recipe for building a SCUBA Tank/ air gun setup? I’m looking for the SCUBA Tank / Air Gun for Dummies Manual.

The manual ideally will contain step by step instructions that include: What tank to buy with what type of valve: What specific connectors, fittings and gauges are needed to say fill a specific brand of air gun cylinder.; Who sells these components and finally, as pointed out, What do I need to know that I don’t know.

One or two step shopping is best: at worst one place for the tank, another for everything else. It’s easy to buy a tank, getting the air from the tank to the cylinder is another matter. It’s not as simple as turning a valve, you need the connecting infrastructure to make it happen. I only have the general overview of what is needed, not the detailed specifics.

Sellers of carbon fiber tanks and hand pumps supply all this in one place since they are specifically designed for air gunning. I can tell them what gun I need to fill, and they supply all that is needed. Not so much with a SCUBA Tank.

Nothing is ever simple. I’ve tried finding a local club or contact that can help with PCP air guns but so far, no luck.

Thanks!

Hello-

You are correct- there is no one source on the topic that I could find. I learned what was best through observing what was used at the Ohio State University range, the CMP- Camp Perry, and elsewhere.

I agree, that I am fully capable of watching to ensure the charge on my cylinders does not exceed 200 bar/3000psi. However, it only takes one mistake,... also, my son, daughter, and grandsons are now using the fill station. I would not expose others to a potential threat from an overfill. Safety first!

This thread has some good information-

viewtopic.php?f=4&t=60454

Best regards,
m1963

I think I got it. I'm at least close.

I need a standard Scuba Tank with a K-Valve. Benjamin, Air Venturi and Air Force make a Yoke Adaptor with gauge and hose. These are made for air guns. Then I just need the appropriate quick connect fitting to fit the gun’s cylinder to the hose. It all just screws together. I found several sources for these items.

Whew! Am I missing anything?

This is all new to me. My only experience with SCUBA Tanks is watching Sea Hunt as a kid on television.

Thanks!

M1963

I just saw your post. Looks like a good tread. I'll see how close I am

Thanks.

Hello-

If you do not want to look everywhere you could buy this tank from Champions Choice-

http://www.champchoice.com/store/Main.a ... s&item=S80

One does not need a pressure gauge, if they stick with a 3000 psi/ 200 bar tank. It can be nice to have, though. With a charging kit you can purge the air before removing the cylinders, reducing stress on the aluminum cylinder threads. The charging kit also makes it easy to switch between different adapters, for more functionality. Those items can be sourced from BEST fittings. A charging kit, and some quick coupling adapters will be needed, for ease of use.

Charging kit- (1/8 BSP)
https://www.bestfittings.co.uk/shop/air ... ton-bleed/

Quick coupler plug (QC) (1/8 BSP)
https://www.bestfittings.co.uk/shop/qui ... er-socket/

Adapter for quick coupler- (1/8 BSP)
https://www.bestfittings.co.uk/shop/qui ... pler-plug/

Female adapter-
https://www.bestfittings.co.uk/shop/fil ... -bsp-male/

The QC plug and adapter for the QC plug are not necessary, but nice to have. They allow one to switch out different filling adapters easily. If you do not get them the Female adapter will screw into the threads on the end of the charging kit hose. It will not be easy to remove, later, though.

All together, it ends up looking like the attached photo. (The hose in the photo is the 2000mm.)

Best regards,
m1963

You don't really need the hose. Best Fittings can supply the fill adapter with the DIN fitting stuck right on the end:
We've got two tanks set up with the most common fill adapters pre-installed into the DIN fitting, and one tank on the far right for use with any fill adapter.

We have students filling cylinders, and for safety, we have a system that can NOT over-pressurize the cylinders. Unless you have a high pressure air pistol that can handle 300 BAR (4500 PSI), and are the ONLY person who ever uses it, get a tank with a K-Valve. That signals to the dive shops not to over fill things. I still get tanks coming back that are at 220 BAR, and I have to vent them down to 200 before the students get to use them.

Unless you are young & strong, I also find an 80 cubic foot tank to be WAY easier to haul back & forth than the 100 cubic footers.

GWhite- agreed, the hose is not needed for filling cylinders. The value, is when one is charging something other then cylinders. A rifle, such as a Daystate can be charged directly at the port on the rifle, and held easily.

M1963, GWhite

Thank You.

The parts look like higher quality than the yoke adaptors I listed. The ones I found must work, but they don’t look as industrial strength. They also connect to the K Valve rather than using the tank’s DIN connection. I’m learning more than I thought I’d ever need to know about Scuba Tanks from YouTube.

Best Fittings is in the UK. Any issues ordering from them (shipping cost, lead time etc.)?

Cost wise it looks like a SCUBA tank set-up is close to a quality hand pump. Hopefully now I can reset my focus back on selecting the right gun.

Thanks again!

We have never had a problem ordering from BEST fittings, in the UK. They are an excellent company with great products. They ship Royal Mail, tracked. You will need to sign for the package when it arrives.

Champions choice You will have everything you need with one phone call. They have guns pellets fittings and tanks. Pilkguns being our sponsor would be worth a call to them first and see if they can provide everything needed. They may not have everything listed on their website but may have everything.

thirdwheel wrote: ↑Sat Jan 18, 2020 7:27 am My Morini fills to 200 bar, as do my steyrs but my pardini fills to 250 bar, I and most others use 300 bar cylinders and fill carefully so as not to over fill - let the air go in very slowly...

This gives me the heebyjeebies! A serious accident waiting to happen.

Bob

To add to the choice of bottles in this neck of the woods we also have "surface air" bottles this means you do not need the adaptor to clamp on the "dive" bottle outlet, there is just a gauge, valve knob and female thread for the adaptor that comes with your pistol to screw into. My smaller bottle has a "slow fill" valve so even with the vale full open the air only goes in slowly, the large bottle is controlled by how you open the valve but it is very controllable and it is easy to get it right using the bottle gauge. Both bottles are sent away for hydro testing and re stamping every five years being surface only bottles.

These are the air tanks used at my club:



And these are the specifications of the different tanks: https://www.ijsfabriekstrombeek.be/en/p ... essed-air/

This is the loading set up:


The small inverted tank you see is for CO2 and sees very little usage.

The red one is not for shooting ;)

Just to confuse the issue more:

Scuba cylinders are generally either aluminum or steel.

Most aluminum cylinders have a working pressure of 3000psi. Some, though, are rated lower, in the 2400 psi range (generally older tanks, from 25+ years ago)

Steel cylinders are also available in different working pressures. Older cylinders (and some specialty new cylinders) are rated from 2250 to 2400 psi. You can get high pressure steel cylinders in 80, 100, and 130 cubic foot capacities that are rated for use at 3500 psi. They are referred to in diving as HPxxx, where the xxx refers to the cf capacity. They typically cost about 3x what an aluminum cylinder does.

As a note on overfilling, the test pressure for scuba cylinders is 5/3 the operating pressure (hydrostatic test, DOT required every 5 years for any scuba cylinder that's going on a road or boat. It's generally voluntarily enforced by dive shops regardless.) The cylinder is filled with water, and pressurized well beyond it's normal pressure. Measurements are taken as to how much the cylinder expands. Too much and the cylinder is condemned. I mention this as a slight overfill of an air gun cylinder will probably not affect too much as long as it is not a standard practice.

The fiberglass or kevlar-wrapped cylinders you see for airgun/paintball applications are rated to 4500psi. I know nothing about recertification of these cylinders. I do know they used to have a limited life span - used to be you could hydro them once then toss them (that was before 2000.) I don't know if that's still true [note: I located one source that said a 15 year use span, so 2 hydro tests.) As an aside, I believe this style of cylinder is in use in Europe as a dive cylinder, but was never certified for use here (again, it's more a DOT thing than a dive industry thing.)

I’ve settled on a SCUBA Tank for my air supply. It’s cheaper and safer than a 300 bar Carbon Fiber Tank. I now know exactly the fittings I will need and where to get them. Thank You.

My original question was “What gun to get?”. I narrowed the choice to a Feinwerkbau P8X or a Morini 162. Any opinions or experiences with either that can help guide me in making my choice? Reliability, adjustability and ease of service are important. I’m pretty sure either is more accurate than I ever will be.

Any practical advantages to the Morini electronic trigger version vs. the manual one?

Thanks!