Air Venturi hand pump: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Air Venturi hand pump
Air Venturi G6 hand pump.

Part 1

This report covers:

  • The great challenge
  • History
  • An experiment reveals a lot
  • The trick
  • The dawn of modern high-pressure hand pumps
  • The Air Venturi G6 pump
  • Today’s test
  • My physiology
  • The test plug

The great challenge

Writing about the Air Venturi G6 hand pump is one of the most difficult reports I’ve ever attempted, because most airgunners know so little about hand pumps in general, and a lot of it is wrong. Also, because the audience for this subject spans the gamut from rank beginners to people who have owned other hand pumps for years, the spectrum of comprehension is infinite. Some people feel this is nothing more than an expensive bicycle pump, so I have to explain how it is different.

I read online discussions of hand pumps among airgunners, and I can tell that only a few of them have any actual experience. It goes beyond the blind leading the blind — it’s more like the blind writing detailed travel instructions to places they’ve never been.

The only way I can think of writing this report is to write it as though my readers have no idea of what high-pressure hand pumps do. Here goes.


Pneumatic airguns have been filled by hand pumps for many centuries. They were specifically made for the guns they serviced — there was no interchangeability or interoperability in those days. So each pump you encounter will be unique. Only in the late 19th century do we start to see similar hand pumps coming from makers. That was probably because the tooling they used to make their pumps dictated what they were able to make — so they repeated their pump designs and specifications for their own convenience.

An experiment reveals a lot

Until Dennis Quackenbush and I experimented with handmade hand pumps that mimicked the pumps of antiquity, I never saw anything in print that reported their performance. Writers mentioned that they were used and how they operated, but nobody said anything about what they could do. Dennis wanted to see what these old pumps could really do (he knew, but he wanted to let me write about it), so he sent me some pumps that were rigged up as test fixtures for me to test. I first wrote about them in Airgun Revue 4 and then repeated that article in a special three-part blog series.

If you are curious about how hand pumps operate, I highly recommend reading that report. To my knowledge, nothing like it has ever been written, before or since.

What we learned was that airguns could be filled to pressures as high as 800 psi with these simple pumps, but it took a very heavy person (240 lbs.) to go that high. That weight is far beyond the average for men of the 17th and 18th centuries. Weighing around 130-150 lbs., they weren’t going to be able to fill as high — it is a physical impossibility. So, the guns they filled had to operate with pressures below 800 psi. Perhaps 500-650 psi might be a more realistic number.

The trick

To pressurize air higher than these antique pumps went takes a smaller pump piston, so the weight or force that’s available can be less. But a smaller pump head means less air (by volume) is compressed with each pump stroke. It is possible to build a hand pump that goes as high as 2000 psi, but because of the very small pump head the number of pump strokes that are required to fill a reservoir with air to that level jumps from a couple hundred to several thousand. It just isn’t practical.

What was needed was a breakthrough in pump technology. A hand pump not only had to have an ultra-small pump piston head, it also needed a larger pump piston head, so the filling would go faster. The solution was a multi-stage pump that contained both sizes of pump heads, working together.

The dawn of modern high-pressure hand pumps

The airgun world was shocked in 1995 when the world’s first high-pressure hand pump hit the market. It was made in Europe and allowed a person to fill a pneumatic airgun up to 3,000 psi. It worked, but there were some serious caveats to how well it worked, because the same physics of the old days were still working. There were not two but three different size pump heads inside the new pump — one nested inside the other. As the pump handle was operated, each pump head fed air into the next stage, where it was compressed higher until the output was an extremely high 3000 psi with the pump force remaining relatively low. This was the modern three-stage hand pump.

However, the term “relatively low” has significant meaning. The force required to pump the new pump was a small fraction of what it would have been if it was a single-stage pump, but it still wasn’t that small. It hovered around 160-180 lbs. that were needed to force the pump handle all the way down. The men of the 1700s would have hailed the modern three-stage hand pump as a miracle, but the men of the late 20th century thought it took a lot of work to fill an airgun. And they were right. Lighter people and people with weak wrists found they could not pump past a certain pressure level. That was why the Benjamin Discovery that only fills to 2000 psi was such a breakthough air rifle.

Okay, that was the genesis of the modern three-stage hand pump. Over the 20 years they have existed, I have read several claims about marvelous technological advancements. I have tested most of these claims and found them to be false. Physics is physics, like the man said. There is a potential advancement that inventor Bob Moss created that I have called the “butterfly” hand pump. It uses a moving pivot point on both sides of the pump rod to magnify the effort applied to the downward stroke of the pump handle, but to date this advancement has not been produced.

Butterfly hand pump
The butterfly hand pump would significantly reduce the effort required to reach the maximum output pressure.

The Air Venturi G6 pump

Having said that, I will now tell you that there isn’t much difference between any of the hand pumps on the market today. Some have desiccant filters that dry the air as it’s drawn into the pump, and all have some kind of moisture trap on the output end. That trap is often packed with small glass balls that allow moisture in the hot compressed air to condense on their relatively cool surfaces. When you bleed the air line, the pressure inside the chamber at the base of the pump rushes out rapidly, carrying all the condensed moisture with it.

I find the Air Venturi G6 pump to be far smoother to operate than the first pumps of the 1990s. The outer pump shaft is finished much finer. Even my 10-year-old Hill pump is rougher than this new G6. What that means is the main pump shaft slides up and down with less friction, and that means an easier pump stroke.

Today’s test

Today I will pump the pump against its test plug and tell you what I find. I did that it Part 1, but today I’m more aware of the pump because I have handled it more.

My physiology

To understand what I’m about to report you need to know something about me. I al 67 years old and in generally good health. I exercise 7 days a week. My resting heart rate is 52 beats per minute when I awaken and 61 bpm at any time during the day. My blood pressure at rest is about 125/72 these days. I am 5 feet 10 inches tall and weigh 220 lbs. I am relatively active for my age and can outwalk most people of any age. This is the person who is about to pump the G6 for you.

The test plug

The G6 comes with a brass plug that can be inserted in the female quick disconnect coupling at the end of the hose any time you want to test the pump. Since it blocks the airflow, you have a contained circuit to test. This allows you to test the number of pump strokes it takes to fill the pump hose to a certain pressure.

Air Venturi hand pump test plug
The brass test plug (arrow) allows you to seal the pump hose and test the pump easily.

I found the test plug difficult to insert in the coupling on the hose until I chamfered the edges that push the ball bearings back inside the quick disconnect. When I did that, the plug went in, though it fit very snugly.

The test

In Part One I linked to a video I made on using a hand pump in 2006. If you are new to hand pumps you really need to watch it, because it shows the right way to pump an airgun. Near the end when the pressure has increased you use the entire weight of your body to press down on the pump shaft. It is vitally important that the shaft goes all the way down, because stopping one inch before that point wastes 50 percent of the air that was compressed by that stroke.

Using this technique, I pumped 5 strokes to fill the pump hose to 100 bar/1,450 psi. That was easy! Then I continued to pump until I had put in another 10 strokes — making 15 strokes in all. I wasn’t watching the gauge, but on stroke 16 I reached the point that I could no longer pump the pump.

Imagine my surprise when I saw that 15 pump strokes had increased the pressure in the hose to 300 bar/4,351 psi. I did that! Me — a 67 year old fat man! That’s why I told you about my physiology. Watch the video, then compare yourself to me and you’ll get a good idea of whether you can use a hand pump to fill a PCP. Reread Part 1 to see my recommendations about which airguns to fill and which ones to leave alone.

I tested it again to see the point at which the pump strokes became difficult for me. That happened on pump stroke 9, when the oil-filled gauge read 170 bar/2466 psi. That’s about the same as all other hand pumps I have used over the years. If anything, the G6 pumped a couple hundred psi higher before becoming difficult. I also noticed this pump is very quiet as it works. My Hill pump is very noisy and so have all other pumps I have used over the years. This one seems much smoother and quieter.

Will it last?

Back in the early days, hand pumps were difficult to maintain. They failed for one of two principal reasons. Either the owners had removed the moly grease from the pump shaft — thinking it was dirt — or the smallest o-ring at the end of the smallest pump head failed from overheating.

In the 20 years pumps have been around, manufacturers have learned how to make them better. The smoothness of the main shaft on this G6 pump is evidence of that. And I bet they have found a small high-temperature o-ring for the critical spot inside.

Besides that, hand pumps have become easier to repair. The G6 comes with 5 sets of replacement o-rings, so they want owners to have them when things fail. Back in the early days, replacement parts were extremely hard to come by.

I have said many times in this blog that hand pumps do not typically fail unless their owners do something wrong. Pumping too long (over five minutes per session) or too fast is one thing that can destroy a pump. Failing to go all the way to the bottom of the pump stroke is another thing you have to watch for, because if you do that you’ll have to pump many more strokes to fill your airgun.

Some owners remove the grease on the outer pump shaft, then they notice that their pump handle failes to stay down after a stroke. The lack of grease allows the outer o-ring to roll out of its groove — setting the pump up for this condition.

There is no way I can tell you how long a G6 pump will last before it needs attention. All I can do is point to the many hand pumps I have owned and tell you that most of them lasted over a decade. But I no longer fill my airguns with a hand pump. I have a compressor that I use to fill by carbon fiber tank, then the tank fills all my airguns. That’s the easier way to fill guns, but the tank and the compressor I own cost a total of $2500. If I were just starting out a hand pump would look more attractive.

You have to make the decision whether a hand pump is right for you. I tried to explain in Part 1 how to do that. If you do decide to get one, I think the Air Venturi G6 pump is a good one.

Common PCP leaks and some common fixes

by Tom Gaylord, a.k.a. B.B. Pelletier

I’m still in Ft. Smith, Arkansas, as I write this, so please excuse the brevity of the report. A while ago, I wrote down this idea as a possible report topic. Those who haven’t yet come over to PCPs often wonder how reliable they are, and those who already have the guns sometimes encounter things that are common problems but new to them. Let’s talk about that today.

WARNING: The procedures I am about to describe are for those who know what they are doing. In every case, there are proper safety steps to be taken so accidents don’t happen. I cannot possibly describe all of those steps, so the following procedures are presented only for your education — not to train you as an airgunsmith. Safety with pressurized air and airguns should always be the No. 1 concern.

I can’t fill this airgun!
Boy, have I ever heard this one! It can come to you in a variety of ways, such as, “This airgun is broken — how do I return it?” I used to get at least one of those calls every month while I was the technical director at AirForce Airguns. The first few times I heard it, I was worried; but I got so used to hearing it that I would start telling them the cure before the problem had been fully stated.

The guy would tell me that he couldn’t fill his old-style Condor tank. I asked him how he was trying to fill it — from a scuba tank or with a hand pump — and a lot of times that made the guy mad. He wanted to know why that mattered because he should be able to fill the gun from a scuba tank or from a hand pump. Right? When this call came in, I knew he was filling with a hand pump, and I also knew he was trying to fill an empty tank.

The answer to “can it be done” is both yes and no. Yes, you can fill this kind of tank from a hand pump if there’s already some air inside it, and no, you can’t fill the tank if you start with it empty. That would really anger some people until I explained that the air inlet valve on an old-style Condor tank is also the exhaust valve. It’s a door that swings both ways. If there’s no air inside the tank, the valve will not recognize the small puff of air from a hand pump and will escape, again.

The valve will not close because it also uses internal air pressure to help it close tight. If you fill the tank from a scuba tank, the incoming air is under so much pressure that it will fill the tank quickly, and the internal air pressure will help close the valve when the filling stops.

A hand pump cannot fill some pneumatic airguns (not just Condors) unless they already have some air pressure inside to hold the inlet valve closed. We would ship tanks out with what we called a maintenance air charge in them — just enough pressure to hold the valve shut. But if the guy received the gun and then proceeded to shoot all that air out, as some of them did, they then had a gun that could only be filled from a scuba tank. It’s not funny when it happens to you.

This phenomenon is not just confined to AirForce guns, either. Almost all of the powerful Korean airguns work in a similar way. But the Korean guns can accept a charge by simply cocking the bolt — sometimes. In that case, taking the pressure of the bolt off the valve allows it to close and seal completely.

The newer style of Condor (as well as all other AirForce sporting PCP rifles) has a Spin-Loc tank with a separate inlet valve and firing valve. I’m not certain, but I believe this has solved the problem I just discussed. If I had a tank and pump here with me, I would check it right now. I’ll look into it when I get home.

Now you know two things about PCP “leaks” that are both very common problems and often misunderstood. First, they aren’t really leaks. They’re part of the gun’s design. Second, some guns must first be cocked to be filled.

Before you go all — “They shouldn’t design them that way!” on me, remember, the SR-71 Blackbird reconnaissance plane leaks fuel until it flies fast enough to heat and expand the airplane’s skin. Only then do all the leaks stop. Sometimes, a product can have a quirk that isn’t a flaw — it’s just the way it works. The Sheridan Supergrade rifle is one that cannot be pumped up unless the bolt is cocked first.

Use a hammer!
I probably shouldn’t tell you guys this next one; because when some of you get a hammer in your hands, every problem looks like a nail. But in the world of pneumatics, there are times when a big rubber mallet is exactly the right tool to use. When is that time? When a pneumatic that has been performing well all along suddenly develops a fast leak. It’s probably due to a piece of dirt that’s gotten onto a soft seal and is allowing air to pass through. To get it off the seal, it sometimes works to tap the end of the valve with a soft hammer. It opens the valve, and the blast of air will probably blow the dirt past the seal.

When I built valves at AirForce, I tested each by pressurizing them in a fixture and tapping the valve stem with a rubber hammer. I had racks of 100 valves at a time, and I went through and did this to each one in turn. That process seated the valve and created a small ring of contact between the synthetic valve and its seat. Sometimes, the valve needed to be hit several times to seat it properly, but it always worked. And it also worked if a valve had a small piece of dirt anywhere in the seals.

When customers would call with a gun that leaked and I determined the leak was a fast one that had popped up all of a sudden, I told them to try this procedure before sending the tank back for repairs. It fixed probably over 75 percent of all such leaks.

But this isn’t magic. If your gun has been a slow leaker the whole time you’ve owned it, this isn’t going to change a thing. It’s just for those all-of-a-sudden leaks that crop up sometimes. It will work for all guns, but most of them don’t allow direct access to the valve head like the AirForce tanks do. For those, you can do the next best thing — dry-fire the gun several times. That usually fixes the problem unless you’re timid about it. I sometimes had to get a timid owner to dry-fire his gun by telling him to fill it full and then dry-fire it 20 times in rapid succession. All that was doing is getting him to dry-fire the gun repeatedly without pausing to see if it was fixed yet. When there’s a piece of grit on a seal, it takes a lot of air flowing past to dislodge it, and a couple tries are often not enough. Twenty shots is probably overkill in all situations, but it saved me time from having to explain in detail just what the guy was doing — as I have now done for you!

You now know a genuine airgunsmith procedure! It isn’t as fascinating as it sounded, is it?

Okay, let’s go back to 1960, when cars had points and copper spark plug wires with (sometimes) poor insulation. Mechanics had a genuine stethoscope in their toolboxes. Or if they were shade-tree mechanics, like me, they had a 4-foot length of small rubber hose. We would put one end of the tube to our ear (the ear that worked best) and move the other end around the engine compartment while the motor was idling. You could quickly zero in on an arcing sparkplug wire or an exhaust manifold leak. It also works for precharged airguns!

You don’t need a hose because the barrel is the pipe that transmits the sound. Cock the gun but don’t load it. The sound you’re listening for is an air leak at the exhaust valve. But here’s an important safety tip — never put your ear directly over the muzzle and never do this if the gun is loaded! Listen from the side of the muzzle; so if the gun were to fire, the air would blast past your ear instead of into it! You can use a piece of paper to direct the sound, if needed. That keeps you safe and still lets you hear the smallest sounds.

I’ve found a number of valve leaks this way. This is just a diagnostic tool — it doesn’t do anything to fix the valve.

If your ears aren’t that good, or if you just don’t want to do it this way, you can also put a few drops of soapy water down the muzzle of a cocked gun. Bubble-blowing solution that you can buy at a dollar store works perfectly for this! If any air is escaping the valve, there will be bubbles at the muzzle. I always had a small bottle of bubble-blowing solution next to me when I worked on guns at AirForce. Of course, you have to clean the barrel and wipe it with an oily patch after doing this.

These little procedures have proven very valuable over the course of time. If the situation is right, they’ll fix the problem more often than not. While they seem simple to the point of being somewhat ridiculous, they do work.

Hatsan AT P1 PCP air pistol: Part 5

by Tom Gaylord, a.k.a. B.B. Pelletier

Part 1
Part 2
Part 3
Part 4

Hatsan AT-P1 air pistol
Hatsan AT P1 air pistol

It’s taken me awhile to get back to this pistol because I injured my hand, so I couldn’t fill the Hatsan AT P1 PCP air pistol from the hand pump for a couple of weeks, but last Friday I was at it again — probably for the last time. You may remember that I discovered that the AT P1 likes a fill pressure of 3,200 psi — which is sort of ironic in light of several recent reports I’ve done. This time, I used the Hill pump to fill the gun to that pressure to see if there are 10 good shots on a fill. That was the problem before — the circular clip holds 10 pellets, but the gun didn’t seem to want to shoot more than 7 of them on a single fill of air.

I decided that instead of wasting time with a lot of different pellets, I would concentrate on the one good pellet that I knew gave the best accuracy. That’s the Beeman Kodiak. First, I filled the gun to 3,200 psi, then loaded the clip and inserted it into the gun. Someone asked me how I held the gun to shoot it, given that it’s scoped with a Leapers UTG 3-9X40 AO rifle scope. The eyepiece has to be held within 2-3 inches of the eye in order to see the image. There’s a way to hold the gun that uses the scope as one of the handles, and that’s what I did. I photographed it for you, so you can see it as I describe the hold.

Hatsan AT P1 air pistol held on bag
This is how I held the pistol on the bag. My hand is holding the back of the scope and positioning it close to my sighting eye.

I hold the back of the scope at the eyepiece and let my hand separate the rear of the scope from my sighting eye by the required distance. My hand is pressed against my safety glasses to maintain the separation. The weight of the pistol rests directly on the bag, so all my other hand does is keep the pistol steady. With this hold, I can squeeze the trigger without moving the gun.

This hold is one I learned while shooting the LD Mark I pistol from Tim McMurray. That’s a Crosman Mark I Target pistol that Tim converts to add a longer bafrrel, a CO2 tank hanging down from the grip and a rifle scope mounted on top — just like this one. With the LD, I rested the external tank on my chest and held the scope like you see here. That gave me near-rifle accuracy.

The result is a steady hold — especially when you consider I’m shooting only 25 yards. I don’t recommend holding a recoiling firearm pistol this way, but you can get away with it on a PCP.

First target
All targets were shot at 25 yards. The first target looked very good until the final shot. I could see that the pistol was grouping low and to the left, but all I was interested in was the size of the group. It could always be moved later with a simple scope adjustment. The group that formed looked very encouraging until the last shot, as I said. I could clearly see that one go high and into the center of the bull, ironically enough. But when I walked downrange to examine the target more closely, it wasn’t as good as it had seemed. A line of four shots appears to the right of the main group, and they’re strung vertically up to the center of the bull. The last one is the highest one. I never saw the other 3 shots in the string, so they could have been any of the preceding 9 shots. All I could see through the scope was the large group that formed at 7 o’clock on the edge of the bull.

Hatsan AT P1 air pistol 25 yards Kodiak target 1
Ten Beeman Kodiak pellets went into this 0.699-inch group at 25 yards.

I guess this first target took the wind from my sails. It was no better than any of the previous targets shot with this pistol. My idea that a higher fill pressure would keep 10 shots in a tighter group was bogus. But I still had time on the range, so I thought something else was in order. I adjusted the scope higher and to the right just a little, to correct for where the Beeman Kodiaks had grouped. Then, I loaded the gun with 10 JSB Exact Monster pellets. The Monster pellet weighs 25.4 grains, making it even heavier than the .22-caliber Beeman Kodiak. And it’s a JSB. I wondered if this might be the pellet that turns things around for the AT-P1 pistol.

Target 2
Alas, it wasn’t. It turned things around, all right, but not for the better. The pellets were all over the place! In the end, 10 of them printed a group measuring 1.933 inches at 25 yards. It’s more of a full-choke shotgun pattern than a group shot from a rifled barrel!

Hatsan AT P1 air pistol 25 yards JSB Monster target
Ten JSB Exact Monster pellets went into this 1.933-inch group at 25 yards. Obviously, not the right pellet for this pistol.

Final target
Now, I was really downhearted. I switched back to the Kodiaks and give them one final try. The gun was, again, filled to 3,200 psi, and 10 more pellets went downrange. This time, the results were not as good as the first time. Ten pellets made a group that measured 1.211 inches between centers. It was higher on the target and also centered better, which proves my earlier statement that the group can always be moved by adjusting the scope, but things were not getting better.

Hatsan AT P1 air pistol 25 yards Kodiak target 2
Ten Beeman Kodiak pellets went into this 1.211-inch group at 25 yards. Though they are positioned better on the bull, this group is almost twice the size of the first one.

Outcome and final evaluation
I put a lot of time and energy into testing the Hatsan AT-P1 pistol. The reward was not worth the effort, in my opinion. While I agree that Hatsan does know how to make a fine precharged air rifle, the AT-P1 pistol is not as refined as the rifles they make. It’s too large and too coarse for what it delivers. I wanted it to succeed because there aren’t that many nice PCP pistols to choose from, but the test results do not live up to the hope.

I think that if you’re interested in an airgun like thi,s you should look at the AT-P2 pistol, which comes with a shoulder stock. That way, you won’t have to learn how to hold the gun like I did here. As long as you know how few shots you’re going to get on a fill of air (7) — and you manage that, you’ll be fine.

Hatsan AT P1 PCP air pistol: Part 4

by Tom Gaylord, a.k.a. B.B. Pelletier

Part 1
Part 2
Part 3

Hatsan AT P1 PCP air pistol
Hatsan AT P1 air pistol

This test is being done because in Part 3, the accuracy test, I felt the scope I was using wasn’t giving the Hatsan AT P1 PCP air pistol the best chance for success. It was a vintage Weaver K856, which means a fixed 8x magnification with a 56mm objective lens. Though it doesn’t say anywhere on the scope, I’m pretty sure the scope’s parallax is fixed at 100 yards. At the 25 yards I was shooting, the target was slightly blurry.

The best group I got in that test was five Crosman Premiers into 0.678 inches at 25 yards. That was shooting off a sandbag rest with a rifle scope.

I said at the end of that report that I would return with a different scope mounted and try again, and today is a report on how that went. The scope I selected this time was the UTG 3-9X40 AO True Hunter that hasn’t hit the market yet. It’s a full-sized rifle scope with a suggested retail price of $104.97, so I would expect to see it sell for something less than that. I’m not going to report on this scope in detail today, but you do need to know that it’s a fine scope for this test. The parallax adjustment worked perfectly, and I was able to get the target bulls into sharp focus. The way I had to hold the pistol to use the scope was a detractor, but it’s no reflection on the quality of the scope, itself. I plan to do a full report on just the scope, but I’ll mount it on one of my rifles of known accuracy.

Hatsan AT P1 PCP air pistol with UTG 3-9 True Hunter scope
The UTG 3-9X40 True Hunter scope was a good pick for the Hatsan pistol.

As I reported, the Hatsan pistol has a proprietary quick-disconnect fill probe that isn’t compatible with other airguns outside the Hatsan line, so I attached it to the hose on my Hill pump. I need my carbon fiber tank for filling all my other PCPs that are universally compatible with the Foster-type quick-disconnect fittings, so the Hill was dedicated to this pistol. It took 26 pump strokes to fill the pistol after 10 shots were fired. That’s 2.6 pump strokes per shot. I said in the last report that the gun seems to give the best results with 7 shots per fill; but since the clip holds 10 pellets, I shot it 10 times per fill. All of today’s groups are 10-shot groups at 25 yards. I feel that’s only reasonable because nobody wants to stop shooting and fill their gun in the middle of a clip.

Shooting was off a sandbag rest, which is fine for a PCP. This pistol does recoil a little when it fires, but that’s well after the pellet has left the muzzle of the gun. The recoil is more of a rocket-like push than a typical firearm recoil, and it’s far from the violent jump of most spring guns.

I overfilled the pistol the first time. I couldn’t clearly see the gauge on the pump and wound up putting 3,500 psi into the gun, rather than 3,000. So, just this one time, I shot 20 rounds on a fill instead of just 10. Had my groups been great, I would have gone back to the chronograph and looked at the velocity again with a 3,500 psi fill.

The Hill pump is great because it allows for such a fill. Other hand pumps peak at 3,000, but the Hill keeps right on going to 3,500. I bought it from Compasseco (which is now owned by Pyramyd Air) years ago when I was testing several BSA and BSA-made derivative PCPs because they’re all pressurized to 3,350 psi.

JSB Exact Jumbo Heavys
The first group fired was 10 JSB Exact 18.1-grain Jumbo Heavy domes. The scope was not sighted in, and the group landed about 4 inches below the aim point and 2 inches to the right. It measures 0.844 inches between centers. While that’s not much better than good, it beats all but 1 of the groups I made with the gun the last time at the range. Since this was 10 shots and not 5 or 7, I have to say that I did measurably better with the new scope.

Hatsan AT P1 PCP air pistol first 10-shot group 25 yards JSB 18-grain
First 10 JSB Jumbo heavys went into 0.844-inches at 25 yards from a rest. This is adequate accuracy, but nothing to shout about.

Since the built-in pressure gauge said there was still about 180 bar left in the pistol after the first group, I loaded the clip with another 10 JSB Jumbo Heavys and shot again. Before shooting, I adjusted the scope through rough guesswork and managed to hit the lower right quarter of the bull at which I was aiming. I really like how well the new UTG scope adjusts, and I like how the knobs can be locked after every adjustment.

Hatsan AT P1 PCP air pistol second 10-shot group 25 yards JSB 18-grain
Second 10 JSB Jumbo Heavys went into 1.053 inches at 25 yards from a rest. The scope was adjusted after the first group was fired.

This is significant. It means there are more than the 7 shots per fill that I reported in Part 3. But I had to overfill the gun to get the other shots. More on that thought at the end of the report.

Please note that the largest of these 2 groups was 1.053 inches for 10 shots. In the previous test, the 10-shot group fired with the lighter JSB Exact 15.9-grain Jumbos was 2.093 inches. This one is a good four-tenths of an inch smaller. I think that is good evidence that the scope is the big difference this time; and if there’s a secondary difference, it’s that I am learning to shoot this pistol. However, I didn’t shoot this 18.1-grain JSB before, so my comparison isn’t perfect.

The trigger-pull was extremely long and mushy as the pistol came from the box, and it does not help the groups one bit. It’s hard to hold steady when pulling through a long, heavy trigger-pull. Also, I have to hold the end of the scope with my left hand to keep the spacing for my eye so I can see through it. If I were to try to freehand it, I would never be able to see through the scope because the image would keep blacking out with small movements of my eye and hand. So, the hold is both difficult and uncomfortable. A pistol scope would be better, though I doubt the groups would get any smaller with one.

Trigger adjustment
The trigger is adjustable, however, and this is one of those rare instances in which the adjustments really work! I adjusted the long pull in my office after the range and got the trigger breaking fairly crisp and quite a bit lighter. This might have helped the groups by some amount.

I’ve tried adjusting this Quattro trigger in some Hatsan spring rifles before and didn’t see as much improvement; but, of course, in a PCP the trigger isn’t holding such a heavy spring.

Beeman Kodiaks
Next, I filled the pistol to 3,000 psi and loaded 10 Beeman Kodiaks. This time I thought I had it right until the two final shots. Shots 9 and 10 went high and right from the main group. Eight shots went into 0.701 inches, but the last 2 shots opened the group to 1.118 inches.

Hatsan AT P1 PCP air pistol first 10-shot group 25 yards Beeman Kodiak
Ten Beeman Kodiaks went into 1.118 inches at 25 yards from a rest. The first 8 shots went into 0.701 inches, and that’s what we’re looking for.

This group sort of reminded me that 10 shots were too much for the AT P1 pistol on a 3,000 psi fill, even at 25 yards. Eight seemed to be the maximum with the new UTG scope. But there was one more pellet to try.

I took Skenco New Boy Seniors along, but they’re too long for the Hatsan’s clip. They protrude and don’t allow the clip to turn when the gun is cocked. The only other pellet I had to try was the Crosman Premier.

Once more, I got 8 shots in a smaller group that measured 0.791 inches, then shots 9 and 10 went wide and opened it to 1.266 inches. One went to the left and the other went right, as though I was throwing curve balls. I couldn’t see the pellets in flight; but when I saw the hole each one made, it came as a surprise.

Hatsan AT P1 PCP air pistol first 10-shot group 25 yards Crosman Premiers
Ten Crosman Premiers went into 1.266 inches at 25 yards from a rest. The first 8 shots went into 0.701 inches, and shots 9 and 10 went wide right and wide left. Once again, 8 shots were relatively close with 2 fliers.

Based on all this data, I’m going to say there are only 8 good shots per fill in this pistol with a 3,000 psi fill. Given the results of both days on the range, I believe I can safely make that statement. But since I was able to fill the pistol to greater pressure and get additional good shots, I think it might respond well to a fill pressure of 3,200 psi and be able to shoot all 10 shots.

The Beeman Kodiaks and Crosman Premiers seem to be the best 2 pellets in this pistol. Next time, I might try a third pellet that hasn’t been tried…like the JSB Exact RS.

Not done yet
I’m not yet finished with the Hatsan AT P1 pistol. In the next test, which I think will be the final one, I’ll try filling to 3,200 psi to see if I can get 10 good shots on one fill. If that doesn’t work, I’ll go back to the 3,000 psi fill and only shoot 8 shots per group. Now that I have a good scope, 2 good pellets, a knowledge of the power curve and fill pressure limits, plus a newly adjusted trigger, I think I can make the gun perform at its best.

Why am I willing to do all this testing? Because there aren’t that many good PCP air pistols available, and I think this might be a good one once I learn all its secrets. I owe you readers that much because so many of you are considering this one.

Hatsan AT P1 PCP air pistol: Part 3

by Tom Gaylord, a.k.a. B.B. Pelletier

Part 1
Part 2

Hatsan AT P1 PCP air pistol
Hatsan AT P1 air pistol.

Today, we’ll look at the performance of the Hatsan AT P1 PCP air pistol for accuracy at 25 yards. It took a long time between this test and the last one because this gun is too loud to discharge inside the house. I had to do it for the velocity test and my ears are still ringing. I waited for a day at the range to test the gun for accuracy.

I mounted a vintage Weaver K-856 scope on the gun for this test. It’s a fixed 8x scope with a 56mm objective lens. I thought it would be clear enough at 25 yards (parallax set for 100 yards), but it turned out to be fuzzy. I will change scopes for the next test.

Hatsan AT P1 PCP air pistol scoped
The vintage Weaver scope was powerful, but it didn’t focus as close as 25 yards. It’ll be changed for the next test.

Before I left the house, I filled the gun to 3,000 psi with the Hill pump. You may remember that this pistol has a proprietary Hatsan fill probe, and I wanted to install it on something I could leave it on for a while. My carbon fiber tank is too busy with other guns, so I dedicated the Hill for this job. Because the AT P1 has such a small reservoir, I felt it would be okay to fill the pistol this way. This is the problem with proprietary fill couplings — they have to be installed on something, making it impossible to use that fill device for your other pneumatic guns that have universal Foster fittings.

After filling the gun, I looked at the Hatsan tank gauge. It read about 50 bar, even though I had just put in 206 bar. I knew it was full, so I left it alone. The next morning, the gauge needle was up to 100 bar, but it never did read correctly. That caused a problem at the range when I shot the gun down too far. It was then that I learned that the gauge needle bears no relation to how much air is in the tank.

I started out shooting a group of 5 Crosman Premiers. The first shot landed a quarter-inch below the next 4. The total group size was 0.678 inches, but 4 of those shots went into 0.322 inches. As it turned out, that was the best group of the day.

Hatsan AT P1 PCP air pistol scoped Premier group 1
This group of 5 Crosman Premiers shows some promise; but for 25 yards, it’s only average. It was the best group of the test!

The trigger-pull was both too long and too heavy for the best in precision. I can normally work around almost anything, but this time the trigger-pull was a real hinderance to good shooting.

I shot the next 5 Premiers at a fresh target after adjusting the scope down. This time, 5 shots went into 0.993 inches, which is considerably larger than the first group. It alerted me to the fact that there may not be 10 good shots on a charge of air.

Hatsan AT P1 PCP air pistol Premier group 2
This group of 5 Crosman Premiers is not so good. It was the second group after the fill. Top hole has 2 pellets.

The pressure gauge on the gun now reads about 180 bar, so I thought there were another 10 good shots in the gun. It wasn’t until later that I discovered the gauge doesn’t read the pressure correctly.

The next 10 shots were JSB Exact 15.9-grain Jumbos. They landed in a group measuring 2.093 inches between centers. That certainly isn’t a good group — especially for just 25 yards. This group has too many shots and was shot with too little air pressure in the tank, but even then the shots are so scattered that I doubt it’s the right pellet for this pistol. But because I don’t know that for sure, I’ll try this pellet again in the next test.

Hatsan AT P1 PCP air pistol JSB Jumbos
Ten JSB Jumbo 15.9-grain pellets were all over the place at 25 yards. Group measures 2.093 inches.

I filled the tank again and changed to Beeman Kodiaks. This time, 10 pellets went into a group measuring 1.464 inches. The last shot went far to the left of the main group. Because it landed in the white, I was able to see it hit the paper. That was the tip-off that 10 shots were too many — even at only 25 yards.

Hatsan AT P1 PCP air pistol Kodiaks
Ten Beeman Kodiaks was obviously too many shots for a single fill. Group measures 1.464 inches.

I’d wanted to shoot 10-shot groups, but the AT P1 doesn’t seem to have enough air for 10 good shots on a single charge. According to the chronograph testing I did on Part 2, it has air for about 7 shots, so I limited the next groups to that.

Hatsan AT P1 PCP air pistol Kodiak 7 shots
Seven Beeman Kodiaks were spread out wide. I was losing my edge on the day! Group measures 0.999 inches between centers.

Hatsan AT P1 PCP air pistol Premier group 3
Seven Premiers did not do well. Group measures 1.675 inches between centers.

The learning curve this day was too steep for me to be satisfied with these results. I’d lost my edge toward the end of the session, and it wasn’t worth pushing on. I’ll return for a second try at 25 yards with different pellets. And I’ll give those JSB Jumbos a second chance. If I can’t do a lot better than this, I won’t bother trying to shoot the pistol at 50 yards.

The trigger-pull on the AT P1 pistol is too long and heavy for the best accuracy. Also, the scope needs to be changed to give the pistol its best chance to do well. Hopefully, I’ll be able to find another good pellet next time and these problems will disappear. As powerful as this air pistol is, it’ll make a good hunting airgun if it can hit what it shoots at.

Hatsan AT P1 PCP air pistol: Part 2

by Tom Gaylord, a.k.a. B.B. Pelletier

Part 1

Hatsan AT P1 PCP air pistol
Hatsan AT P1 air pistol.

Today, I was all set to report the velocity of the .22-caliber Hatsan AT P1 PCP air pistol, when I discovered that there’s more I need to know about this airgun. I’d like to thank those who’ve been waiting patiently for this second report. I stalled for a long time because Hatsan uses a proprietary quick-fill probe. That means I have to undo one of my more universal fill connectors to attach their probe. Thankfully, the threads on their probe are standard 1/8″ BSPP that connect to most air hoses coming from tanks and hand pumps these days (I can still remember when that wasn’t true!), but I was working on both the Condor SS and the twist-rate report and needed a fill device for both of those. In the end, I pressed my Hill pump into service, and it proved to be a great way to fill the AT P1 pistol.

Rotary clip
The first problem I encountered was with the 10-shot rotary clip — but I want to stress that it wasn’t the pistol’s fault. It was mine. I tried loading 28.4-grain Eun Jin domes that looked like they fit the clip well, but proved to be too long and jammed the gun.

Because they were the first pellet I tried, I thought the gun might be broken until it dawned on me that the pellets were the problem. Once I changed to Crosman Premiers, the gun functioned perfectly and there were no more cocking or feeding problems.

Rotary clips are sensitive to the length of pellets. If they stick out on either side of the clip, that can cause the gun to jam, as this Hatsan did. So, when selecting pellets for a rotary clip, keep this in mind. I chose the Eun Jin pellet for the weight. I thought it would allow this powerful pistol to develop its maximum power, but I went too far.

Removable air reservoir
In Part 1, I completely neglected to mention this pistol has a removable air reservoir. I saw the degassing tool in the tool kit and knew that it could only be used on the other (hidden) end of the reservoir, but for some reason I didn’t think to mention it.

Hatsan AT P1 PCP air pistol reservoir removed
The air reservoir unscrews from the pistol. When it’s out, it can be emptied by the brass tool at the bottom.

Of course, the reason for a removable tank is so you can carry extra charged tanks in the field. Each one will give you more shots. I don’t think this is such a great feature after you learn how many shots you can get on a fill, but the choice is yours. At least Hatsan gives you the option.

Shots per fill
This will be the remainder of the report because I discovered during velocity testing that the AT P1 pistol has a very specific power curve. It’s not an inverted bathtub curve — where the velocity rises to the optimum level and remains there for a number of shots before falling back down again. Instead, the velocity rises, peaks and drops instantly. The curve looks like a peaked mountain with no flat spot at the top.

The manual says to fill to 3,000 psi and that there are 35 useful shots per fill. Several readers expressed doubts that the 50cc reservoir held enough air to give 35 powerful shots, and I agreed with them. If this was a target pistol, then 35 shots would be very possible; but at the power Hatsan claims, which is a .22-caliber pellet traveling 780 f.p.s. at the muzzle, it seems impossible to get 35 good shots on so little air. And, indeed, it isn’t.

My first fill was higher than 3,000 psi, and the velocity was depressed for many shots. When it did rise, it did so in a straight up and straight down fashion. There was no group of shots going at similar velocities. This told me I needed to control the fill very carefully.

I also noticed that the pistol fell off the power curve with about 1,800 psi remaining in the reservoir. But I didn’t stop shooting there. I stopped with about 1,500 psi remaining in the reservoir. From this test, I was able to determine that the pistol used about 62.5 psi per shot. I did that with a chronograph and with an accurate pressure gauge on the hand pump. The pressure gauge that’s built into the test pistol’s reservoir reads several hundred psi too low to be of much use.

I know how much air is in the reservoir when I start shooting because that’s what the pump’s gauge reads when I stop filling. I know how much air is in the reservoir when I stop shooting because that’s the spot on the gauge where the reservoir inlet valve is overcome by pressure during the next fill — you can see this when the gauge needle clicks at the opening of the inlet valve.

It took 1.5 pump strokes per shot, so refilling the reservoir went very quick. That’s why I believe the Hill pump is the best way to go, and the possibility of spare reservoirs isn’t worth the effort.

The shot count test
The next test I conducted began with a fill to exactly 3,000 psi on the hand pump’s pressure gauge. I used Crosman Premier pellets, exclusively for this test. I’ll give you the velocity readings and then interpret them afterward.


I’m not going to give you an average for this string because I don’t know which shots you want to consider as the good shots. Clearly, the pistol was slower at 3,000 psi on the hand pump gauge. And, remember, this is with the more accurate hand-pump gauge. The pistol’s built-in gauge was still showing about 2,700 psi at this point. Either way, there’s too much air pressure in the gun because the valve isn’t opening as long as it should, as evidenced by lower velocities.

Let’s say I like 761 f.p.s. for the first shot. If you agree, then the first 5 shots in this string were wasted. At 62.5 psi per shot, the gun was overfilled by 312.5 psi when it was filled to 3,000 psi. Since these gauges don’t read that accurately, let’s round that back to 300 psi overfill and say I need to stop filling the reservoir when the pressure gauge reads 2,700 psi.

If you select a different velocity as the start point of the shot string, then the beginning fill pressure will need to be adjusted accordingly. This is why I am not giving you an average velocity today. I can give average velocities, but before I do you need to know what is behind my numbers, because this pistol operates within narrow limits.

If I take the second reading of 761 f.p.s. as the ending shot in the string, there are a total of 7 good shots in the string. I think that’s probably too restrictive, and I need to expand my velocity variation allowance. If I allow a velocity variation of 74 f.p.s. between the fastest and slowest shots in the string, I can get 16 good shots on a fill and can start the fill at exactly 3,000 psi.

Do you see how I’m doing that? I’m using the chronograph numbers and accepting all shots until the pistol no longer drives Crosman Premiers out the muzzle at a velocity of greater than 700 f.p.s. My choices are arbitrary; but until I make them, I can say nothing about the shot count of this pistol

Well, maybe that’s not entirely true. Whatever I select as the acceptable velocity variation, I can say with certainty that this air pistol can never get 35 useful shots on a single fill. Where I draw the line is my choice, of course. If I want to shoot groups at 50 yards, the variation has to be tighter than if I want to hunt with the pistol out to 30 yards. Do you see how the anticipated use of the gun drives the useful number of shots you’re going to get?

When you change the clip, the gun must be cocked to pull the loading probe back out of the clip. Then, the clip’s axle must also be withdrawn to the front of the gun and held out of the way. That’s a separate brass bolt on the right side of the gun. The clips come out and go back in easily enough when these things are done.

Hatsan AT P1 PCP air pistol cocked
A lever on the left side of the gun is pulled to the rear to cock the action and advance the clip to the next pellet.

Hatsan AT P1 PCP air pistol bolt probe
Here you see the bolt probe that pushes the pellet into the barrel (brass pin in the clip recess) and the brass clip axle (the head is a brass knob) that’s been withdrawn to the front of the gun to remove the clip.

Discharge noise
This gun is LOUD! I had to wear electronic ear protectors when testing it in my office. And although my office door was closed, my wife, Edith, remarked on the loud discharge when I was finished.

In the next report, I’ll test the pistol with several good pellets and give you some of the velocity data you’re used to seeing. But when I do, you’ll know what’s behind my numbers.

2013 SHOT Show: Part 3

by Tom Gaylord, a.k.a. B.B. Pelletier
Photos by Earl “Mac” McDonald

Part 1
Part 2

The SHOT Show is not a gun show — though that is what many attendees call it, and the mainstream media that doesn’t attend also calls it that. Instead, it’s a happening — to use a 1960’s term. Or it’s a Middle Eastern open market. The big booths house the recognized names like Colt, Winchester and Crosman. Their booths are two stories tall with signs hanging from the ceiling that you could see a mile away if there weren’t other signs hanging in front of them.

But the real drama of the show isn’t at those booths. People already know what to expect in those places. It’s the little out-of-the-way booths hugging the walls that have the surprises. I always set aside some time just to cruise the aisles, looking for some rocks to turn over.

I’ll be walking along a narrow aisle and someone will step out to stop me. Then, in a conspiratorial tone, he leans over and says something like, “Don’t you just hate it when your ice cubes melt and dilute your drink? Cold Bars have solved that problem forever. These are sanitized stainless steel bars that retain the cold almost as well as water, plus they’re reusable forever. Put three of these in your scotch and soda, and it’ll be as fresh and strong after 20 minutes as when it was poured. When you finish the drink, just pop them in the freezer for 10 minutes…and they’re good to go again. While you wait, you use the second set of three bars in your next drink! Nothing could be easier.”

This guy is serious! You look at his spartan booth and realize that he has poured everything into this venture because at some point watery drinks pushed him over his tipping point. When he bounced the idea off his wife and friends, they all agreed it was the next big thing. They had no idea he would mortgage the house and put his life savings into it!

So, here he is, in a narrow aisle of a large trade show, hawking his brains out to people who, for some reason, just don’t seem to get it. Who doesn’t want cold, undiluted drinks?

Think I’m exaggerating? Attend a trade show and walk the aisles some time.

Why do I plod through these pathways of personal misery? Because next to the stainless steel ice cube booth there ‘s the G+G Airsoft booth that has the best action target I’ve seen in a long while. It’s a lighted rubber hemisphere that’s computer-controlled to react to being hit by an airsoft BB. You can turn the light on or off, depending on how you have programmed it.

They call it the MET Unit, which stands for multifunctional electronic target. It can exist as one single target or they can be strung together in up to 25 targets for a prolonged target array.

airsoft action light targets
The MET Unit is from 1 to 25 programmable lights that turn off or on when hit by an airsoft BB.

The wires between targets can be up to 50 meters in length, which allows them to be set up in a tactical course and either light up at some random time until hit or stay on for a programmed time and go off after the time is up or when hit. Two competitors can shoot at the same target and change the color of the lights when they hit it, establishing a duelling target.

The individual target will sell for $66 or 5 for $250. It looks like a great way to have fast-action fun with airsoft guns. They can take hits from AEGs shooting 0.20-gram BBs at up to 450 f.p.s. Naturally, they’re not robust enough for even the lowest-powered steel BB or pellet guns.

Umarex is now branding airguns under their own name. This year, there are three new long guns: the Octane is a breakbarrel with a Reaxis gas spring and SilencAir, which is a baffled silencer; the Surge is an entry-lever springer breakbarrel; and the Fusion is a CO2 pellet rifle, and it also has the SilencAir noise dampener. We’ve seen the Fusion before, branded as the Ruger LGR, but Umarex tells me the Fusion is a Gen 2 upgrade and quite different. I never got the chance to test the LGR, so I’m looking forward to testing the new Fusion as soon as possible.

Umarex Fusion
The Fusion is a new CO2 single-shot rifle from Umarex that sports a 5-chamber noise dampener.

I spent an hour at the Leapers booth this year. The most important thing I wanted to see was the new scope with an internal bubble level. It’s a 4-16x in a 30mm tube, and it looks exactly like what the doctor ordered for those long-range targets we love to shoot. They’re working hard to get it to market this year, but it won’t go out until they’re certain of the quality. Putting a bubble level inside scopes on a production line is apparently quite a challenge…but one I’m sure Leapers will do correctly.

The entire line of scopes have been upgraded with finer adjustments — many of them 1/8-minute adjustments — and greater repeatability. They have a broad range of adjustment in both directions, and their production models are even exceeding the maximum limits they established! All leaf springs have been replaced with coil springs to increase adjustment precision and repeatability.

But the WOW factor comes on the stuff you can see. How about a 3-9x scout scope (10-inch eye relief) with a wide field of view? That is the big trick for scout scopes, and I saw a beauty mounted on an M1A — though it would be just as correct on a Mosin Nagant.

Leapers scout scope
Leapers new scout scope has a full field of vision — something scout scopes are not known for.

Another surprise from the folks in Michigan is the smallest tactical laser I have yet seen. I asked Mac to photograph it next to a quarter for scale.

Leapers small laser
Leapers new laser is the smallest I have yet seen. That’s a quarter next to it.

Back to the Crosman booth to show you what the new Benjamin pump looks like when the handle is raised. I didn’t expect the huge reception this pump got when I showed it the first time this year. Please note that it has not one but two pump tubes. This is a 3-stage pump — the same as the current pumps, but this one compresses a bit more air with each stroke. I’ll have more to say about it when I test it.

Benjamin pump extended
Maybe this view will help you understand how the new Benjamin pump magnifies the force you put into each pump stroke.

I’ll close with a last look at the Hatsan booth. They have the AT-P carbine and AT-P1 pistol…and both are precharged pneumatics. They’ll come in .177, .22 and .25 calibers that each have hunting levels of power. These are repeaters with circular clips and adjustable Quattro triggers. The sights are fiberoptic, and there are provisions for scopes. The air cylinders remove, and spares will be available as options.

For those who are looking for hunting air pistols, I think these two should be considered. I’ll work hard to review them for you as soon as possible.

Hatsan PCP pistol and carbine
The Hatsan AT-P2 Tact (left) and the AT-P1 are exciting new PCP airguns.

Leaving the show
As Edith and I left the show we passed by one final booth. The guy is selling Instant Water for survivalists. Just drop one of his pills in a bucket of water and — Presto! — instant water. Why I can’t think of things like that?