Hammerli AP20 PRO cylinder hand pump charging

[huckleberg]

On the cylinder for the Hammerli AP20 PRO (or any similar size cylinder) how much effort is involved if using a hand pump to completely charge? I've seen lots of videos and mentions of filling larger rifle cylinders but haven't anything about pistol sized cylinder/tanks.

[Gwhite]

It can be a bit of a workout. You definitely want to fill AFTER you shoot. My problem is that I'm not heavy enough to get all the way to 200 Bar without "throwing" myself down on the pump handle a bit. I'm 175 pounds & 5 foot 8 inches tall, and it may be that being a bit short also limits how much mass I can get above it.

[huckleberg]

It can be a bit of a workout. You definitely want to fill AFTER you shoot. My problem is that I'm not heavy enough to get all the way to 200 Bar without "throwing" myself down on the pump handle a bit. I'm 175 pounds & 5 foot 8 inches tall, and it may be that being a bit short also limits how much mass I can get above it.

How long do you have to pump to get as far a you can? Luckily, I am 220lbs of rock solid pure muscle* so I am sure I can do fine.

* Bridge for sale, Brooklyn, cheap! PM for details.

[GoodEnuf]

Short answer --- significant but not overwhelming effort involved...

Long answer: Based on my experiences with the FWB P34 and FWB P8X cylinders, and the Anschutz CA 2002 rifle, and using the FX 3 stage and FX (Gehmann) 4 stage pumps, consider the following -

- pistol cylinders take about 70 - 90 strokes, depending on depth of previous discharge; rifle, many more

- the pump will heat up to the point of eventual seal destruction if the pump is stroked to the point of overheating. You can easily heat it up to
be almost hot to the touch.I burned up my 3 stage pump on rifle cylinders, which is why I now have the new 4 stage pump; the first pump lasted
19 years however.

- note that the fourth stage of a 4 stage pump can be shut on or off with a twist of a knob - it makes pumping a little easier, but requires
more strokes for the same delivery volume. I turn it on at 150 bars to ease the pumping effort.

- to prevent overheating of the pump (and me), I limit pumping to a slow and deliberate 35 strokes, which is about 3 minutes of work. The pump
is barely warm to the touch at this time. Rest, or put the pump and cylinder (still attached) aside for awhile, and pump again when all is cooled
down. It takes 2 or 3 cycles of this to fill a cylinder, again, depending on previous discharge depth. A little arithmetic shows this to be about
10 minutes to fill a nearly empty cylinder. I have several cylinders so always keep 1 or 2 ready for use, and fill the empty (s)
when convenient. As Gwhite said, exerting yourself before shooting affects scores.

- pumping too fast is inefficient; slow, deliberate strokes work best for me

If you have arthritis or other such problems be sure not to overdo it at any one time, and watch your technique. You can gain by using your legs (and body weight) over using just your shoulders and/or arms. In my experience, shoulders and elbows are at risk of injury with too much pumping too quickly. For context, I am shorter and heavier that Gwhite - 5'6" and 205 lbs, and north of 70YOA, and expect to use the pump for a while longer. I shoot about 400 - 500 shots/week, so fill ~3 cylinders a week. As a side note, I have the pump and cylinder around and pump while watching TV, filling in the commercial time with the pumping.

With those cautions, the pumping can be rationalized as good exercise, and an alternative to the diving tank systems, especially to occasional shooters without easy access to compressed air. If you shoot a lot, or have physical limitations, I suppose an air compressor may be the
better alternative.

JE, from the Cascadia Subduction Zone

[m1963]

Perhaps not, the answer you are looking for. Buy a tank and forget the pump. Really, the pump is a huge source of water=corrosion, into your cylinders and high dollar pistol!

[Ramon OP]

Is the pump really that nasty on cylinders? If it was @GoodEnuf would have had lots of trouble during the decades he's been using them. I've also spoken with coach Daniel Goberville about this and he says that as long as you pump with the valve open 4 or 5 times before and after filling it is not really an issue.

Do you know of any sources that have reliable information about this? I'm preparing a post about pumps for Olympic Pistol and I've only found hearsay.

The pump manufacturers have not been cooperative so far.

[deadeyedick]

Take m1963’s advice. Pumps are a good way to waste money and will give the appearance that you have a nervous disorder.

If you are insistent on buying a pump and proving me to be wrong then...

1. Do as GWhite has suggested and pump after....or at least two days before a competition.
2. Have some nitro glycerin tablets in readiness to place under your tongue.
3. Have a bottle of Yukon Jack ready to soften the buyers remorse when you realise how
silly you were to spend good money on something so bloody ridiculous.

p.s. If you have enough money to employ a “ worlds strongest man contender” to do the pumping for you please dismiss 1, 2 and three.

[pbrejsa]

I have the same experience as GoodEnuf or Ramon OP. I have been using a Gehmann hand pump for over 15 years. The inner space of the cylinders (Steyr, Morini) is still like new after this time.

If the air cylinders are in good condition and the inner surface is well anodized and free of all chemical impurities, even any internal moisture will not cause corrosion. Water condensate is only distilled water. The life of such cylinders will last for decades. As well as the service life of the hand pump, when used correctly and consistently in accordance with the seller's recommendations
http://www.gehmann.com/manuals/m220-m100-de-en(1).pdf

Note: The stupid requirement of administratively limiting the service life of cylinders made of aluminum alloys is not a pleasure. When the organizer of the competition requires this, I always borrow a cylinder with the corresponding year of production.
If this were really important, above all, it should be forbidden to fill the cylinders at the area of competition range. It is dangerous to fill, no use of the cylinder screwed onto the gun. That is all.

[m1963]

The last pump I had, a Hill, became so corroded due to moisture that it quit working. This, even though I followed the directions that came with it. I did rebuild the pump twice; but each time the corrosion was worse and the parts were harder to remove.

[pbrejsa]

Hello-
I don't know the Hill pump. So I have no experience. I have two Gehmann pumps, one home in, the other at the cottage. Both without problems. Occasionally (annually) I lightly lubricate and protect the surface with a thin layer of almost liquid silicone grease. I do not lubricate the inner pistons. I store under normal ambient conditions without changing temperatures. I pump at normal room temperatures. I shoot 20 to 25 thousand shots per year, that's about 10 to 13 thousand strokes.

[huckleberg]

Perhaps not, the answer you are looking for. Buy a tank and forget the pump.

I have no convenient way to fill the tank, local dive shops require a dive card.

[huckleberg]

3. Have a bottle of Yukon Jack ready to soften the buyers remorse when you realise how
silly you were to spend good money on something so bloody ridiculous.

Straight Rye for me ...

[huckleberg]

Hello-

Perhaps not, the answer you are looking for. Buy a tank and forget the pump.

I have no convenient way to fill the tank, local dive shops require a dive card.

Actually I may have just found one that will let me sign a waiver promising not to dive with the tank.

[pbrejsa]

to m1963
The most important thing for a huge pump life is to prevent it from overheating. Pumping several cylinders in quick succession reliably removes the seals of the new pump. The best way to know this is at a shooting range or during a competition. Your friends will give you a disservice.
In such cases, it is more appropriate to use a diving bottle.

[Gwhite]

Perhaps not, the answer you are looking for. Buy a tank and forget the pump.

I have no convenient way to fill the tank, local dive shops require a dive card.

Actually I may have just found one that will let me sign a waiver promising not to dive with the tank.

I'm not sure where you can get one, but there are large stickers that used to be available that say something to the effect of "This cylinder is for airguns only, and is not to be used for breathing". That tends to calm down most dive shops.

[spektr]

Note: The stupid requirement of administratively limiting the service life of cylinders made of aluminum alloys is not a pleasure. When the organizer of the competition requires this, I always borrow a cylinder with the corresponding year of production.
If this were really important, above all, it should be forbidden to fill the cylinders at the area of competition range. It is dangerous to fill, no use of the cylinder screwed onto the gun. That is all.
[/quote]

The cylinders were not end of lifed administratively....
The NRA and ISSF rulebooks were brought into compliànce with International Pressure Vessel Regulations which were revised to end of life cylinders in this class at 10 years. It has nothing to do with it being aluminum. It has to do with a lack of designed inspection access to the tank and the inability to verify condition. This was the end result of small high pressure cylinders in our class failing in SOLAS service in the maritime survival industry...... We were caught up in it due to the class our cylinders live in and the capacity floor listed in the annex to the regulations....... I dont like it either, but it is the law.......

[pbrejsa]

OK. What is or is not a pressure vessel is decided by the internal volume and overpressure and the resulting value, not by the ISSF Committee. Can you give the number of your International Pressure Vessel Regulations and the limits for air cylinders, eg guns? From my point of view and from the technical point of view of the given regulations, I repeat only an administrative decision with the tacit consent of the manufacturers. Just business, business only or coping with poor product quality or poor design. So far cracked cylinders on air weapons burst much earlier than after 10 years This is true and manufacturers are only fogging up, because it is a weak point but also an opportunity to earn some extra money.
It has been associated with aluminum extruded material for 10 years. For steel cylinders, this is set at 20 years.

[spektr]

OK. What is or is not a pressure vessel is decided by the internal volume and overpressure and the resulting value, not by the ISSF Committee. Can you give the number of your International Pressure Vessel Regulations and the limits for air cylinders, eg guns

Certainly.....Please go read these.

The Specifics on the law are here
PED 97/23/EC Annex 1 Article 1 (1)
Annex 1 Article 1 (2.3)
Annex 1 Article 1 (2.5)
Annex 3, 1.1

What you will find after digesting this is your answer.....
The US DOT enforces the PED by reference in its regs....

Compliance with this law which was quite lax at the time, was the reason behind the USA Shooting 3/13/13 memo. It started enforcement of the 10 year end of life as the law required, putting in place the requirements with almost no explanation as to why it happened....

There is also the phased implementation of PED 2014/68 EU, but that is primarily involved with changes to fluid group 1 and 2, and the enforcement chances brought by the EU changes.

Hope this helps.....

[pbrejsa]

Thank you, I know this standard. Nothing new. The standard contains the definition of a pressure vessel (bar x liter greater than 25). For example, the cylinder of a Steyr pistol or Morini pistols are not pressure vessels according to this standard, because their volume is less than 1 liter and the pressure does not exceed 200 bar. (Steyr cylinder signed V = 0,068L air max.200 bar). This means unlimited service life or specified by the manufacturer. In this example, the rules for use and inspection and maintenance are specified only by the equipment manufacturer if he deems it necessary. The problem can occur with cylinders with an operating pressure greater than 250 bar and a volume greater than 0.1 L, ie with some air rifles. Which also happened in the 1990s at the beginning of the production of extruded cylinders. However, the cause was always poorly produced and processed input material and poor extrusion technology. Your example with breathing vessels for survival in inadequate conditions of use of air cylinders in air weapons for ISSF disciplines. All manufacturers prohibit exposing and using these weapons outside of normal ambient conditions (aggressive environments, extreme temperatures, etc.). Or will you allow seawater, acid or lye to flow into the cylinder? The recall action of Morini a few years ago (perhaps 2016 production) to finally show that the cylinder rupture was caused by improper maintenance and use. When I want to force each cylinder to burst, by mechanical overload, corrosion or external mechanical damage, but never by the recommended way of use. If the airgun manufacturers and the ISSF Steering Committee have only been able to limit the use of Al alloy cylinders to 10 years only and protect the safety of the shooters, it is doubtful from my point of view. It's always just about money. Or just stepping outside ....

[spektr]

Respectfully......
We are indeed below the 1/2 liter floor, BUT that doesnt define what is or is not a pressure vessel. The chart is very specific that cylinders in our class are end lifed at 10 years. It also codifies the requirement that the manufacturing quarter and year shall be identified on the vessel and a CE stamp shall be applied indicating compliance with a CE standard...

The serialization of and the application of a CE stamp would not occur if they were not regulated pressure vessels......

I guess we will have to agree to disagree agreeably, but it is nice to see somebody actually read the standard.....

Have a great weekend