by B.B. Pelletier

Part 1
Part 2


This is the actual rifle I’m testing. Isn’t that wood beautiful?

Before I begin, at the end of this report there is a lengthy Q&A section in which Dr. Mirfee Ungier, wife of Pyramyd Air owner Joshua Ungier, answers a number of questions about protective eyewear and other related shooting issues. Dr. Ungier is a respected ophthalmologist with thousands of successful surgeries to her credit, and she agreed to answer readers’ questions about protective eyewear.

Today, we’ll look at the accuracy of the HW 100 S FSB PCP air rifle I’m testing. Throughout this report, I’ve mentioned how impressed I am with this airgun for various reasons. It has the easiest-loading metal rotary clip in the business. You can see the pellets advance in the clip, and now I know that you can even see them when a scope is mounted. That makes the rifle very easy to manage — like knowing when you’re shooting the last shot. And, then, there’s the trigger! This one is perfect for me. It breaks cleanly at 8 oz. and has a positive two-stage release. I couldn’t ask for more.

The rifle is light, or at least it feels light when you hold it. The scale disagrees, but I can’t get away from the lightness I feel. Also, the stock happens to fit me perfectly. Though that’s a very personal thing, you can’t overlook it when it works out your way.

On the down side, I noted that the rifle recoils about the same as a heavy .22 rimfire rifle shooting standard speed ammo. It’s an unfamiliar feeling to have a smallbore PCP recoil. The shot count that the chronograph said could be as high as 38 shots on a fill actually turned out to be about 25, like I first noted. I will show you the evidence on two of the targets.

For this test, I mounted an older version of the Leapers 8-32x56AO scope that was used in the test of the Crosman Outdoorsman 2250. While it was too much scope for the little carbine, it was a perfect fit on the Weihrauch PCP. And, it allowed me to see the bulls at 50 yards very clearly. It was mounted in two-piece B-Square adjustable scope mounts that are no longer available. I’ll soon be showing you a new adjustable scope mount that may solve your scope adjustment problems, in case you do not already own one of these vintage American-made B-Squares.


On the big HW 100, the Leapers 8-32×56 looks right. It’s mounted in a vintage high B-Square adjustable mount that’s no longer available.

Accurate right from the get-go
I enjoy shooting accurate guns, because they cooperate to produce such wonderful results with so little work. The HW 100 is one of those. Even the sight-in group was impressive enough to show you. I selected the 18.1-grain JSB Jumbo Exact Heavy as my sight-in pellet, simply because one owner said he got such good results with it in his .22 rifle.


This is the sight-in group — the first 10 shots made after the scope was mounted. It’s ten 18.1-grain JSB Exact Jumbos at 50 yards and it measures 0.795 inches between centers. It’s the largest group fired with this pellet.

Then, I settled down and shot a couple more groups with the same pellet. I’d adjusted the point of impact to the exact center of the crosshairs, so on the first group I shot out the aiming point with the first couple shots.


Ten more JSB Exact Jumbos went into this group, which measures 0.667 inches between centers. This is a phenomenal group. After the first couple shots, I had to estimate the location of the center of the bull because it had been shot away.

Learned something important
I tried to shoot a third group of 10 shots, and this is when I learned that the HW 100 doesn’t like to shoot that many shots per fill. At least, it doesn’t if you expect accuracy at 50 yards. Look at the grouping and I will explain.


The first two shots went through the center of the bull. The next two shots are at 5 o’clock on the edge of the black. The rifle is now low on air and the point of impact just shifted as a result. This is part of the proof I mentioned in the beginning of this report that the rifle falls off the performance curve very suddenly.

It occurred to me that I may not have filled the rifle to the exact maximum on the first fill. Taking that into account, I watched the rifle’s manometer as I filled the reservoir the second time, and stopped exactly when it hit the top of the green area, which is an indicated 200 bar or 2,900 psi. But as you will see, the needle is quite fat and a bit imprecise.


The onboard manometer (pressure gauge) is located on the end of the air reservoir, where it can be seen easily during a fill.

On the second round, I learned another important thing. This rifle is slightly overfilled when the needle on the manometer is pointing at the max fill spot. In other words, I should have learned where the right high end point was on my more accurate tank gauge and stopped there, because I’ll show you what happened.

On the next group, the first two shots were in the lower right portion of the bull, then they miraculously jumped back to where they belonged in the center. Even so, this was the tightest group of three shots with the JSB 18.1-grain Exact pellet.


The first two pellets went to the 5 o’clock position, while the other eight went closer to the point of aim. Even with this, the group measures only 0.571 inches between the centers of all 10 shots. It’s the best group of the test. This proves that the rifle needs to be exactly on the power curve to shoot its best. Omitting those two shots and the group shrinks to 0.368 inches. Remembering that most writers only shoot 5-shot groups for the record instead of 10, here are 8 that went well under half an inch!

Now I was on a roll and expected the other pellets to perform equally well. They didn’t though. After reading an owner’s report of the gun, I’d selected the best pellet for the rifle and started the test with it.

Beeman Kodiak copper-plated pellets were the worst pellets of the four I tested. They grouped 10 shots into a startlingly large 1.907-inch group at the same 50 yards that JSB Jumbos had made a group less than one-third that size. They were a shock and disappointment, but also a reminder of just how sensitive an airgun can be when it comes to ammunition.


This group of Beeman Kodiak copper-plated pellets was disappointing after the success of the JSB Jumbos. It measures 1.907 inches between centers.

Next, I tried the old favorite 14.3-grain Crosman Premier. At just 14.3 grains, it’s screaming downrange at the ragged edge of accurate velocity, and perhaps just a touch too fast. That’s why they gave a larger group that measured 1.225 inches for 10 shots.


Ten Crosman Premiers went into this group that measures 1.225 inches at 50 yards. It’s not that bad, but we already know this rifle is capable of much better.

The last pellet I tried was the equally brilliant JSB Exact 15-9-grain dome that works so well in a multitude of spring and PCP rifles. I expected great things from it. Alas, it was not to be.


Ten 15.9-grain JSB Exacts went into this group, which measures 1.187 inches between centers. It isn’t as good as I had hoped for this pellet.

Well, the results could not be any clearer. This rifle loves the 18.1-grain JSB Exact Jumbo to the exclusion of the other premium pellets I tried. It also develops the greatest power with this pellet, so nothing is lost by using it.

The HW 100 is also very sensitive to its fill pressure. As long as you stay within the boundaries, the rifle is capable of incredible accuracy; stray out on either side, and the pellets will wander.

The bottom line
If I could justify keeping this fine rifle, I would. But that isn’t going to happen. I already own several accurate PCPs, and my gun storage facility can only hold so much. So, we’ll be shipping it back to Pyramyd Air very soon. Whoever wants to own this particular beautiful tackdriver should request serial number 1921933.

Dr. Ungier’s answers
Now, we have some answers about protective eyewear questions and related topics from Dr. Mirfee Ungier.

Q. Is polycarbonate OK for the applications we are talking about (pellets and BB’s)?

A. Polycarbonate is more than OK as a safety glass material. ANSI standards have moved entirely to polycarbonate and away from plastics like CR39 (industrial plastic). It may scratch more easily, but maintains its integrity and protective function the best.

Q. If polycarbonate lenses take an impact, does that mean they’re done and you have to get new ones? I believe that’s what they tell us about bike helmets.

A. Polycarbonate can take impacts without cracking or chipping, but you do have to look at it. Especially rimless ones may chip. If there’s any visible defect, replace them. It is much cheaper than replacing an eye.

Q. What are the long-term effects on a person’s vision from frequent use of rifle scopes?

A. I am not aware of any downside of using scopes. People do all the time. If anyone using a scope notices a problem with their vision, they should, of course, get an eye exam. I think of people who use scopes are quite aware of what they are and are not seeing. When they come to me, they are usually better able to communicate than people who do not use their eyes as much. Using eyes is a good thing.

Q. What adverse effects can class III laser sights have on a person’s vision, and how much (or how little) exposure does it take for damage to occur?

A. I am not aware of a study regarding laser time exposure and damage to the eyes. These may not be at the nastier wavelengths, but all lasers by definition are highly coherent beams that can pack a punch. I use red beam aimers for directing other wavelengths into the eyes for therapeutic reasons, and I still try to avoid the center vision. Short glances into a laser scope will probably not cause harm in the short term, but we never recommend it, and you certainly wouldn’t play with them.

Q. What should we do if the unthinkable happens and someone is struck in the eye? What should we do while transporting the individual to the closest ER? What are the emergency first-aid procedures that we should follow?

A. If a serious eye injury occurs, there is no on-the-spot treatment you can do. In fact, most important is to not press on the eye. It is OK to shield it, but pressure could turn a bad injury into a worse one. Then proceed as quickly as possible to an emergency room in a hospital that is equipped to do eye surgery. Calling ahead to be sure would be great. If you are far off the beaten track, then any emergency facility would be OK. During working hours, you could see if there is an ophthalmologist (I mean ophthalmologist, not optometrist or optician, because we may be talking surgery) in town to examine and expedite treatment. Otherwise, call an optometrist for recommendation for the closest facility.

Q. I was wondering if the age of Tom’s old safety glasses could have contributed to their easy destruction. Do time and sunlight degrade the efficiency of protective safety glasses? For instance, what’s the shortest time period in which you should you trust the material integrity of your glasses and be safe while shooting?

A. Safety glasses scratch, age and degrade. Old ones are better than none, but my optician recommends replacing them at least every 2 years.