Posts Tagged ‘precharged pneumatics’
by Tom Gaylord, a.k.a. B.B. Pelletier
This is a third look at the Disco Double shooting at 50 yards. All I’ve managed to do so far is demonstrate the Disco Double is very consistently mediocre with the best pellets — JSB Exact Jumbo RS domes. However, the last time I was out at the range with this rifle, I finally did what the builder, Lloyd Sikes, has been telling me to do all along. He said to tighten the 6 screws on the 2 barrel bands or hangers, and this time I followed his directions. Guess what? Four of the 6 screws were loose! Imagine that! I tightened them and knew the rifle would reward me for the effort.
It was no surprise when shot the best 10-shot group ever with the rifle. Ten RS pellets went into 1.195 inches at 50 yards. But I was 3 shots into a second group when the bolt handle broke off in my hand during cocking. That ended the day for this rifle.
As soon as I returned home, I emailed Lloyd, who put a new bolt and handle in the mail right away. I really wanted to finish the test before leaving for the Ohio airgun show (which is this Saturday), so I disassembled the rifle. I ran into a problem getting the old bolt out, but a call to Lloyd set me on the right path and soon the job was done.
The new parts arrived the following week, and I had them in the rifle inside an hour — though another call to Lloyd was necessary. He was most helpful, and I resolved my problem with a minimum of fuss. The rifle went back together, and I was ready to return to the range.
This time, I took the opportunity to mount a new UTG 6-24X56 scope scope in place of the UTG True Hunter 3-9X40 scope I took off. Naturally, the target image was much larger with this scope, which just made my job easier.
I tried several pellets that I’ve tried before, but once more this rifle demonstrated that it likes the JSB Exact Jumbo RS pellets the best. Since the rifle had been taken apart for the bolt repair (i.e., both barrel bands had been removed), I was back at the beginning on the first group. I had the front band about where it had been before (from the screw marks in the paint), and the first group of 10 went into 1.28 inches at 50 yards. That was marginally better than the 1.317-inch group I’d gotten during the previous full test, but not quite as good as the one group I shot just before the bolt broke (1.193 inches). All the screws were tight, so now it was time to move the front barrel band.
In case you don’t understand what moving the front barrel band has to do with accuracy, it comes down to harmonics. By changing the location of where the barrel is anchored, I changed how the barrel vibrates during the shot. I did a huge 11-part test of this effect a few years ago. You can read about it here.
I moved the front barrel band backwards about a half inch and tightened the 3 screws once more. Then, I fired another group of 10 shots. This time, 10 RS pellets went into 0.816 inches. That’s pretty telling, don’t you think? Of course, I have no way of knowing if I have the barrel band adjusted perfectly — all I know is that it’s better than it was before.
A second 10-shot group went into 1.506 inches. Oops! Was that supposed to happen? Its difficult to say, but perhaps I wasn’t concentrating while shooting this group. I simply don’t know. Stuff happens to me, just like anyone else!
So I shot a third 10-shot group. This one measures 0.961 inches between centers. That’s better.
What I can tell you now is the that Disco Double is able to put 10 pellets into less than an inch at 50 yards under ideal conditions. I’ve shown you everything that’s happened, and I could go on and continue to test this rifle until I have it shooting its best. I probably will, in fact. But the lesson is what I’ve shown you today.
The Benjamin Discovery is an inexpensive PCP that can put 10 pellets into less than one inch at 50 yards under ideal conditions. The Disco Double I am testing for you here has a lot of extra work done to it and is not as inexpensive as the basic Discovery. However, this is the air rifle I wanted. It’s small, it’s accurate, it has a wonderful trigger and this one gets a load of shots on a fill of just 2,000 psi. That’s everything I wanted in a PCP.
Best of all, this rifle weighs no more and is no larger than a standard Discovery. Despite the additional air capacity, I had to sacrifice nothing. That was the real reason I had this air rifle built. Lloyd Sikes has a wonderful thing going here. If you’re interested in what he can do for you, find him at Airgun Lab.
by Tom Gaylord, a.k.a. B.B. Pelletier
This report was requested by blog reader Rob 8T2 and seconded by a number of others. I reported on the spring piston forward spring guide that’s known as a top hat, and he wondered if I was also going to talk about the AirForce top hat. Though they share the same name, the two items aren’t connected in any way. One is a spring guide, and the other is an adjustable valve stem for a pneumatic valve. The adjustable valve stem draws its name because, like the forward spring guide, it also looks like a gentleman’s top hat in profile.
The sliding breech cover has been pushed forward, cocking the striker and revealing the breech for loading. This is the original valve from a first-generation AirForce Talon without a power adjustment wheel.
To understand the AirForce top hat, we have to go back in time to before AirForce Airguns air rifles had power adjustment wheels on the left side. In January 2000, I reported on the new AirForce Talon, the first air rifle to be offered to the U.S. market by the new AirForce company. But I’d already owned the rifle I tested for two years. I bought it from the UK company, GunPower, in 1998, when it was configured differently and sold as their Stealth rifle. In late 1999, AirForce Airguns sent the parts to reconfigure my rifle to their new Talon specification, with an 18-inch .22-caliber barrel.
By that time, I already had many hours of testing and shooting on the rifle in its original Stealth configuration with its 12-inch barrel. It was during that time, by talking to AirForce owner and creator John McCaslin, that I learned how to adjust the top hat of my rifle to change the power.
You may find it amazing to learn that I could adjust that rifle to fire from 65 f.p.s. all the way up to 950 f.p.s. with 14.5-grain Eley Wasps. In truth, any velocity below about 400 f.p.s. was just a parlor trick. The rifle could do it, but all consistency was lost. From 400 to 950, though, it was fairly consistent.
How the top hat power adjustment worked
Power was adjusted by screwing in the top hat to shorten the valve stroke and the valve dwell time (the time the valve stayed open). The valve stroke became shorter because the wide flange at the base of the top hat contacted the top of the valve body and stopped moving. Then, the valve return spring started pushing the valve stem closed again, aided by the high-pressure air inside the reservoir.
Conversely, a longer valve stroke meant more dwell time and more air flowing out. At some point, however, the pellet left the 18-inch barrel, and the longer valve stroke stopped having any additional influence. Once the pellet’s out of the barrel, no amount of additional air can push it any faster.
To loosen the top hat for adjustment, unscrew a tiny 0.050″ Allen screw in the large knurled bottom flange of the hat, allowing it to turn on its threads. Once the desired clearance was reached, the small screw was tightened again. This screw caused problems because enthusiastic owners were over-tightening it, causing it to put dents in the hollow valve stem it contacted. In later years, AirForce started putting two screws in this flange to increase the locking pressure and hopefully reduce the damage to the valve stem.
The o-ring secret
Adjusting the top hat was a chore. One day, airgunsmith Tim McMurray told me about an easier, more convenient way. He said to slip a rubber o-ring around the top hat flange, so it rode in the space beneath the flange. It very effectively limited the amount of valve stem travel. Once I found out how good it was, I left it in place all the time. I wasn’t interested in sheer velocity. I wanted good accuracy at a reasonable level of power. Nothing has changed in 14 years, has it?
Talon SS puts an end to top hat adjustment
In November 2000, I wrote about the new Talon SS, which was the first AirForce rifle to have a power adjuster on the left side of the gun. My own SS was a pre-production prototype that didn’t have the power scale engraved on the side of the rifle; but after 14 years of continuous use, it’s still working fine and the air tank has never leaked.
The Talon was also updated with the power adjustment wheel at the same time. Now all AirForce sporting PCPs have power wheels and the top hats no longer need adjustment.
John thought that the power-adjustment mechanism would put an end to the fiddly top-hat adjustment, but it didn’t! By the time the power adjuster came on the market, there was a lot of interest in AirForce Airguns…and the internet was abuzz with homebrew ideas of how they should be set up and operated. People did use the new adjustment, but they also continued adjusting their top hats. Top hats continue to be adjusted and discussed right down to today!
The truth about the top hat
The truth is that the top hat is still a very influential part of the AirForce system. It does have tremendous impact on the rifle’s operation, though not always in the ways you read on the internet. Now that the rifles have the power adjustment wheel, the top hat has become more of a starting point or a setting that gives each rifle a potential range of power. The power adjustment wheel is what fine-tunes that range. The top hat is a set-and-forget kind of adjustment, only people are not leaving it alone.
Some valve stems are very thin, such as those found on the Hi-Flo valves. When the screws are over-tightened on these valves, they dimple all too easily. That’s one reason I advise owners not to adjust their top hats.
Top hats are set at the factory with feeler gauges. I’ve told several people I once discovered that an American quarter coin was exactly the right thickness to set the top hat for a Condor Hi-Flo valve. I’ve actually done that more than once. A difference of one or two thousandths of an inch from the factory spec usually isn’t critical. But when the difference grows larger than that, it does start to become critical. It depends on which rifle you’re talking about to determine if the difference is critical.
For the record, I left AirForce Airguns in 2005, and a lot of things have changed since then. I’m not qualified to give out factory specs on anything they make today. I don’t adjust my top hats at all. I use the power adjuster 100 percent of the time when I adjust, and most of the time I leave each gun set at the position that gives me the greatest accuracy.
You wanted to know about the AirForce top hat — there you go.
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.
by Tom Gaylord, a.k.a. B.B. Pelletier
This is a second look at the Disco Double at 50 yards. On this day at the range, the wind was quiet, so it was a good day to test.
I didn’t do anything to the rifle before this test because I didn’t have any time to stop long enough to clean the bore. So, it went uncleaned. I may have promised to do certain things before the next test, but all I actually did when the time came was grab the rifle and go back to the range.
I used the same black single sandbag you saw in the Daisy model 8 test earlier this week. The Disco Double perfectly fits the long groove of that bag and feels more secure than if it was in a conventional rifle rest.
The first group was made with 10 Beeman Kodiak pellets, and they were on target since I’d already zeroed this rifle at 50 yards for the earlier test. They initially stayed together, and I thought the rifle might have turned the corner. They then began to fly farther and farther apart. In the end, 10 pellets went into 1.837 inches — hardly a group worth mentioning. When I checked back to the previous test, though, I noted that this same pellet had made a group that was 2.458 inches at 50 yards; so as bad as it is, this was an improvement.
Okay, that wasn’t the brilliant opening I was anticipating. Even though the same pellet beat the last group by half an inch, it didn’t seem like the time to gloat. Next up were the JSB Exact Jumbo RS pellets — the most accurate pellets in the first 50-yard test.
The first group was another teaser. It looked small through the scope. It wasn’t until I measured it that I found out it went over an inch. Ten RS pellets went into 1.317 inches at 50 yards. That’s smaller than the smallest group from the previous test. There, 10 RS pellets went into 1.3418 inches at 50 yards. This group is similar, but it’s not crushingly better by any means.
I now have 2 groups — each of which is better than the same pellet in the previous test. One is significantly better; the other is only better by a whisker. What does that mean? Rather than try to answer that question, I decided to shoot another group. Surely, this one would be conclusive!
The next 10 RS pellets went into a 1.773-inch group. That was the hands-down worst group of both days of testing for this pellet. On the same day, shooting under the same conditions with the best pellet, I got both the best and worst groups this rifle had fired to date.
I’m sure someone can make sense out of these results — but I’m not that person! After 2 days of testing at 50 yards, I had not proven anything except that I can’t make this air rifle shoot — yet!
I considered shooting some more groups; but after looking at these results, I thought this wasn’t the day. Sometimes, the bear gets you!
I think what I’ll do is drag the Disco Double to the range every time I go and try to shoot different pellets each time. Maybe then I’ll stumble across the magic pellet that turns this rifle into a shooter. After testing similar rifles, I’m convinced this gun can shoot — I just haven’t yet discovered how.
by Tom Gaylord, a.k.a. B.B. Pelletier
I’m still in Ft. Smith, Arkansas, filming segments for this year’s American Airgunner TV show, so today’s report will be short. After I reported the 50-yard accuracy test for the EscapeUL, blog reader Gunfun1 asked me if I had remembered to coat the pellets with Slip 2000 oil that Ton Jones likes. I had to admit that I’d forgotten, so I promised him I would. Last Friday, I went to the range and shot the EscapeUL with just the 2 best pellets — the 43.2-grain Eun Jin pointed pellet that develops the maximum power in the rifle, and the Predator Polymag pellet that was the most accurate on lower power.
The first pellet I shot was the Predator Polymag. I did that because the rifle was still set on the same power setting I used in the last test. If you recall, I shot 2 groups of Polymags that time. One was 5 pellets in 0.622 inches at 50 yards. I thought that was phenomenal! The second group of 5 opened up to 1.298 inches, but I shot it in a continuous wind. I just waited for quieter moments, but the wind was always blowing for that group.
Oiling the pellets
I put several drops of the Slip 2000 lube on the foam that JSB packs in the tops of their tins. Predator Polymags are made by JSB, so they always have this foam. Then, I put some pellets on the foam and rolled them around until they were moist to the touch.
The first target I shot looked like it was going to beat my earlier best group; but after 3 shots, the rifle threw the next shot to another location, opening the group much larger. Okay, I thought, maybe I didn’t get the fill pressure just right. I continued shooting until there were 6 shots on this target. The entire group measures 1.545 inches between centers. That isn’t bad; but in light of what I did before with unoiled pellets, I wasn’t happy with it.
This group suggested to me that the EscapeUL doesn’t like oiled pellets. It seemed like once the bore was oily, accuracy went south. Of course, I couldn’t let it ride without testing it once more. This time, the pellets were oiled in the same way, but the bore was already oily. I mention that because the next group of 5 wasn’t nearly as good as the first. Five Predator Polymags went into 2.634 inches! And that was what I expected would happen. When I saw the pellets in the previous group opening up, it was something I have seen before. Oiled pellets often do this, in my experience.
The wind was starting to pick up, so I switched from Polymags to Eun Jins. This time, I ran the power up as high as it would go and filled the reservoir to 3,000 psi. The last time, I shot 5 dry Eun Jin pellets into a group that measured 1.866 inches at 50 yards. That set the bar for the oiled pellets.
And the challenge was met! I got an almost-identical 1.862-inch, 5-shot group with the oiled Eun Jins. The measurement error is larger than the difference between these 2 groups!
Sometimes, you win…and other times not
I know this isn’t a huge test with lots of controls and numerous targets. But I didn’t think oiling the pellets was actually going to help. From what I see here, it didn’t. It’s just one extra step for little or no return. I certainly would not oil the Predators, again!
The one advantage I see with oiling is that it makes the pellets load easier. At least it does for the Predators. The Eun Jins load very hard no matter what you do. I had to use the flat side of the screwdriver blade on my pocket knife to get them into the breech — even after oiling!
I doubt I’ll oil pellets for this rifle again.
by Tom Gaylord, a.k.a. B.B. Pelletier
Today, we’ll look at the accuracy of the new .25-caliber AirForce EscapeUL. This is the ultra-lightweight version of the Escape rifle and has most of the Escape’s power but is more than a pound lighter. The Escape is already lightweight, but at just 4.25 lbs., the EscapeUL is a real featherweight.
The day I chose to test this rifle was very cold, with a threatening breeze that soon picked up to a 20 m.p.h. wind. I did all of my shooting between puffs and gusts.
Because this rifle is so potentially powerful, I decided to test it all-out with the first 2 pellets. The power adjuster was run up as high as it would go and the tank was filled to 3,000 psi. The first pellet I tested was the heavyweight 43.2-grain Eun Jin pointed pellet. As you’ll recall from my tests of the Escape, I’m shooting 5-shot groups instead of 10-shot groups because the velocity decreases with every shot. At 50 yards, I can keep 5 shots in a good group, but trying to do that for 10 in a row opens things up. There are still 10 good shots on a fill, but you have to change your aim point to use all of them.
The first group measured 1.866 inches between centers. That’s with a pellet that produces from 70 to 80 percent of the power of a .22 long rifle bullet, so it’s plenty potent. The Eun Jin pellets are not the most accurate in these rifles; but for power on target, they’re pretty hard to beat.
Next, I refilled the rifle and tried the same thing with the 35.8-grain Eun Jin dome. This time the group opened to 2.506 inches between centers. In light of the heavier pointed pellet’s accuracy, I don’t think I would use this pellet in this rifle.
Experience comes in handy
I’ve said many times that a shooter can adjust these AirForce rifles so much that you’ll never be able to test everything; but, fortunately, there’s a better way if you have some experience to go on. And I did have some experience because I’d already tested the Escape rifle. While it does have 6 inches less barrel and a thinner barrel to boot, the rest of the EscapeUL is pretty much the same as the Escape. I felt that if I went in the direction that gave some success with the Escape, it might work with this rifle, as well.
JSB Exact King
I knew that the Lothar Walther barrels in AirForce rifles like JSB pellets, and in .25 caliber the JSB Exact King pellet is a real performer. When I tested the TalonP pistol, the King was one of the best pellets, and you know the Escape rifles are all based on the TalonP platform.
I also knew that I should reduce both the starting air pressure in the tank and the power setting to do well with the King. But I wanted to see if it could handle the full 3,000 psi; so, the tank was filled to the max, but the power setting was dialed back to setting 8. I started shooting and was so successful that I kept right on after the fifth shot. Eight shots went into 1.61 inches at 50 yards. I would have shot another 2 shots but this time the air pressure had dropped to 2,000 psi on the built-in gauge, and I thought the next shot might go somewhere else.
Next, I tried the Kings with the same power setting (8) and a starting air pressure of 2,600 psi. I shot just 5 pellets that went into 1.209 inches at 50 yards. That was definitely the best the rifle had done to this point, but I’d seen even better accuracy from the Escape, so I decided to shoot these pellets again.
A second group of Kings with the same fill pressure and power settings produced a 1.526-inch group. That was still good, but I felt the rifle could do even better. It was time to switch pellets.
Ton Jones has done more testing than I with these rifles, and he likes the Predator Polymag pellet the best. Even when he knows the Eun Jin pointed pellet produces more energy, he trusts the Predator Polymag to go where he shoots. That was the next pellet for me. I filled the tank to just 2,500 psi and set the power at 6.
I expected a good group, but I wasn’t prepared for how good! Five Polymags went into 0.622 inches at 50 yards. Despite the cold (20 degrees F) and the winds that were gusting to 20 m.p.h., this hollowpoint pellet was drilling them in!
Predator calls their Polymag a pointed pellet, but I call it a hollowpoint. The point is just a plastic tip that’s glued in place. The pellet acts like a hollowpoint on game, so I call it one regardless of the plastic tip. Just a little quirk of mine, I guess.
That first group was stunning. By now, the wind was blowing all the time, and my day with air rifles had ended. I did shoot a final group of Polymags in the wind, waiting out the gusts and shooting when the wind was down to about 5-10 m.p.h. The same setting and fill pressure was used. This time, 5 pellets landed in 1.298 inches at 50 yards, and I can truthfully say it was the wind’s fault. However, this group is still the third best of the day, which says a lot for the Predators in a reasonable wind. I think Ton is right — this is the best pellet for the Escape rifles, but you have to lower the power and fill pressure.
More to do
As with the Escape rifle, I’m not done with the test just yet. I need to get the velocity figures for the best pellets, power settings and fill pressures so we have some idea what this rifle can reasonably do in the field. Before I do that, I want to try the EscapeSS first.
Summary so far
Most shooters will look at the Escape’s raw power and choose it over the EscapeUL on that basis, alone. But I look at the light weight, compact size and the stunning accuracy of the EscapeUL and think it would be my pick, so far. From the standpoint of muzzle report and recoil, there’s very little difference in these 2 rifles. Both are loud and both kick like a rimfire rifle — perhaps even more. But there’s still one more rifle to test.
by Tom Gaylord, a.k.a. B.B. Pelletier
The suggestion for this report came from blog readers ricka and Terd Ferguson, who both expressed concerns over the safety of precharged airguns. That’s safety…as in wondering if one can blow up!
It’s been a long time since I felt those same concerns, but I did at one time. Before I got my first PCP in 1995, I was quite concerned about keeping a scuba tank filled to 3,000 psi in my house. I’d seen the movie Jaws and was suitably impressed when the shark was blown up by a scuba tank at the end. So, these two readers are probably expressing the same concerns that hundreds of you share. I’d like to address those concerns in what I hope will be a straightforward series of reports that are easy to understand.
Do firearms blow up?
Veteran readers of this blog know the answer to that. Firearms do blow up, and I’ve shared at least one such personal story with you — my Nelson Lewis combination gun. I overloaded it and blew the percussion cap nipple out of the barrel! You can read that report here. In retrospect, it was my fault, so we can call that experience a stupident.
I’ve been involved in two other firearm blowups. One was caused by a rim failure in a .17 HM2 rimfire cartridge, and I’ve since come to find that this cartridge is known for that weakness. When it happened to me, shards of hot brass blew out the ejection port of the 10/22 clone I was testing for Shotgun News. One piece of brass cut my right arm and drew some blood; but aside from that and a lot of extra noise and smoke, no other damage was done. That event was out of my control, so it was an accident.
The other blowup was caused by a squibb round (one without gunpowder that drives the bullet into the barrel but not out again) in a Colt SAA revolver. I was firing very fast; and when the squibb happened, I was unable to stop before I thumbed off the next round. The revolver’s barrel was split lengthways when the second bullet hit the first one halfway down the barrel. That wasn’t an accident — it was a stupident.
Shooting a round into a bullet that was already lodged in the barrel burst this 7-1/2 inch Colt SAA barrel. The bullet was struck where the ejector housing screw was.
Do precharged airguns ever blow up?
Yes, they do. The causes are as random as they are with firearms, and the results range from sudden surprises all the way to death. The blog readers are entitled to a frank discussion of the kinds of accidents that can happen with precharged guns, and that’s what I’m about to give you.
When I bought my first precharged rifle—a Daystate Huntsman—and a brand new 80 cubic-foot aluminum scuba tank, I was properly awed. No, make that frightened. It was not unlike setting off my first charge of TNT in the Army! I respected the power potential of both that dive tank and the airgun I was filling.
Like any new thing, though, this awe and respect lasted only as long as it took me to become comfortable with the technology. If you do something enough times, the edge of respect starts to wear off—I don’t care what it is. It isn’t good when this occurs, but it’s human nature. Familiarity breeds contempt.
And then it happened. My gun blew up! Okay, it wasn’t actually the rifle; it was the hose that connected the rifle to the scuba tank. And to be honest, it didn’t really blow up. The soft wall of the rubber hose ruptured, violently releasing compressed air. The tear in the hose wall was about one inch long, and the warning signs were there before it happened. The hose had developed a noticeable bulge at the point the blowout occurred. That should have told me that the reinforced fabric liner under the outside rubber was failing, but like I said—familiarity breeds contempt. And I didn’t want to stop shooting my airgun. I took a risk and the explosion happened.
I was standing in my basement when the hose blew. The noise sounded like a concussion grenade, although I’m quite sure it was nowhere near as loud or forceful. The blast loosened a storm of dust from the floor joists above my head; and my wife, whose office was right above me, jumped out of her seat.
The net result was no injury to me, beyond a bruised ego, and no physical damage to anything other than the now-ruined hose. I was momentarily stunned, and it took about 15 seconds before I regained my bearings, because Edith had already gotten to the basement before I turned off the tank’s air flow.
I shared my experience with other airgunners who were more acquainted with precharged airguns and was told I had been lucky the hose hadn’t broken off completely, whipping me violently before I could turn off the scuba tank’s valve. That was when I discovered that nearly everyone who uses precharged airguns has either had an incident like this happen to them or knows someone who’d had one.
Can this be avoided?
Can this kind of incident be avoided? Absolutely! There are several things you can do to keep this from happening. First, if you use microbore air hoses, the likelihood of blowouts is reduced — not eliminated, just reduced. Microbore hoses carry the same internal air pressure as regular hoses, but the surface against which the air presses is so much smaller that it reduces the amount of stress on the hose material. However, most microbore hoses are stiff and will eventually soften at the point at which they are bent. That’s usually up near the tank, where they come out of the tank’s air valve. You still have to watch for that, because when they soften, they also weaken at the same spot. The hose I have linked to in this report has springs on both ends to prevent this bending to a large extent — but you still have to look for it.
Another safety measure is to use a hose that has a braided steel sheath on the outside. This sheath keeps the rubber that’s underneath from expanding and blowing out. The hose that blew out on me was an early rubber Daystate hose that had just a 3,000 psi rating. It was rated for nearly the same pressure it worked at (2,500 psi), which isn’t good. The hoses with braided steel sheaths are rated much higher.
The stainless steel wire braiding on this air hose will prevent it from blowing out.
The most important safety measure is you! Examine your fill equipment every time you use it; and if you spot something like I did, you stop right away.
Another type of stupident
If you fail to fully connect the two halves of the Foster quick-disconnect coupling during a fill, the air pressure will disconnect it for you! It will be accompanied by a small explosion and often by the violent whipping of the air hose. Here’s another place where a microbore hose protects you because it doesn’t whip as much, plus it’s smaller, so it doesn’t hurt as much when you get hit. But the best thing is to never get hit at all. When you make the connection, listen for the click of the knurled ring on the larger female fitting as it snaps into position. That indicates that all the ball bearings inside the coupling are now safely inside the groove of the male fitting.
This female Foster fitting (left) has a spring-loaded collar that pulls back to allow the ball bearings to move outward. They go around the flat spot on the male fitting on the right, then the spring pushes them into the groove. They will hold the two fittings together under pressure, but only when the ball bearings are in the groove. It’s important to hear the two parts click together.
That is as far as I will go in this report. I know how important this information is for many of you, so I promise to come back to this quickly for part 2.
For now, however, I want to leave you with this thought. I’m being honest with you about the potential dangers that are present whenever precharged airguns are used. You have to keep an open mind about this because the things I’m presenting are not that common. They do happen and most of them can be prevented by the means and methods that we’ll discuss.
Operating a precharged airgun is no more dangerous than having a gas-fired hot water heater in your house or operating a lawn mower. There are things to be aware of; and if you follow the rules, no harm should come your way.
In 2009, I gave Pyramyd Air two articles about the basics of precharged pneumatics:
While I put a lot into both articles, there will be new things in this series of blog reports.