TargetTalk

I have 2 Hammerli AP 40 air cylinders that are leaking. I am hoping that someone on this forum can direct me to where I can have them rebuilt.

Most companies will refuse to rebuild/repair cylinders because of the 10 year rule. There are no provisions in the rules for rebuilding or recertification. It's all based on the original date of manufacture. Unless the cylinders are very new (in which case I would discuss getting them replaced under warranty), it's not economical to repair them.

The college team I help coach has dozens of AP40 cylinders. I have a couple "in-date" AP40 cylinders that leak, and when I opened them up, it looks like the valve assembly is crimped together. It's not designed to be repaired. Most of the newer ones we have that leak do so out of the gauge end. I haven't had time to figure out how to swap those out. I think you have to unscrew the gauge with a long wrench from inside the cylinder.

I personally find the gauges on cylinders pretty useless (I have with and without). I would pour a gurgle of liquid epoxy down to the gauge and be good to go.

The Hammerli (now Walther) gauges are especially poor. They are not very accurate (like +/-20 bar). We may have gotten a bad batch, but we have 4 or 5 of around 2014 vintage that leak. By contrast, the gauges on our Benelli Kites are excellent. They never leak, and are much more accurate. The Kite cylinders are also slightly larger in diameter, with larger gauges to match, that are also easier to read.

just thinking out loud. If the gages leak. Epoxy putty them closed, mark the gages inop and just fill them at the start of the shooting session....

It may be the gauge, or it may be the seal between the gauge and the cylinder body. Right now we are getting ready to go to the Collegiate National Championships in two weeks, and I have plenty more pressing projects.

My hope is that I can either replace the O-ring that seals the gauges to the cylinders, or steal good gauges off some out-of-date cylinders and get the in-date ones working again. They have changed the design of the gauges over time, and I'm not sure if I can do the swap.

I just checked an old cylinder I opened up, and I can't detect any sort of hex (male or female) down inside, but it's hard to focus down that far. That means the gauge has to be removed from the front, but I have to take off the crystal, remove the needles, and then figure out how to get the face out to access the innards.

If it was just for me, I would have no issues plugging the gauge. For the students I help coach, we have enough trouble getting them to shoot matches with full cylinders with working gauges. We have a bunch of AP20's where they have to use a separate gauge to check the pressure, and they are constantly shooting them down to the point where you can hear the shots losing speed.