by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
- Test plan
- How many tests?
- Backwards planning
- Test design
- Start — 4.50mm heads
- Discussion of the 4.50mm head
- 4.51mm heads
- Discussion of the 4.51mm head
- Discussion of today’s testing
On Friday I told you I wanted to clear a backlog of reports. This is one of them. When I was at the Pyramyd AIR Cup in September of last year, I was given two sample packs of a new .177-caliber pellet from H&N — the Baracuda FT (for field target). Florian Schwartz, the director of H&N, told me this new pellet was designed for air rifles shooting at 12 foot-pounds and less. But new airguns and other equipment kept pushing the test back until last Friday, when I decided to suspend the history section for awhile to catch up.
Many people think that testing a pellet involves putting a PCP into a vise and shooting it at a fixed target. Do you know what that will tell you — how well a PCP in a vise shoots the pellet. Will there be correlation between that kind of test and the real world in which a living person shoots the same pellet from the same gun that’s not in a vise? Yes — SOME. But not as much as many people think.
Don’t get me wrong — testing a pellet with a gun that’s locked down is probably an important part of the overall test plan, but it can’t be all the testing that’s done. If it is, the test is incomplete and there may be surprises when the pellet goes on the market.
I am going to test these pellets in a real gun that’s shot by me. I will describe how I shoot the gun each time I test in a different gun. And that is another thing — you can’t test pellets in just one airgun. To test a pellet, you need to try it in as many different airguns as practical.
Herr Schwartz gave me 10 tubes of pellets. Five have a head size of 4.50mm and five have a head size of 4.51mm. Each tube of pellets in the group of five is a different lot number. While they sat in my ammo cabinet from the end of September 2018 until today, February 8, 2019 (the date I’m testing) one of the plastic packages broke open and three of the five tubes fell out. My first job, therefore, was to determine which tube in that package went with which lot number.
These are the 5 lots of Baracuda FT pellets with 4.50mm heads. This package broke open and three tubes fell out. When I figured out the German numbering system, I put the tubes back in the package and photographed it for record.
The Germans labeled each tube of 70 pellets with a paper sticker. They put them into the package in ascending numerical order — at least in the package that was still unopened that was the order. At any rate, when I put them back and when I ran the first test, I used them in the order seen here. So whether I got the order right or not, the Germans can see which lot I’m talking about.
This pellet package of 4.51mm heads did not break open, so I couldn’t rotate all the paper labels up. When I opened it I was careful to record which label went with which lot number. This package was the one that confirmed the lots were by ascending numerical order.
I am still talking about the test plan! Once all the tubes are out of their packaging we lose the correlation to which lot number they belong to and even which head size they are. That had to be determined and recorded before the tubes were taken from the packages.
It’s a little late to try to figure things out when you get this far. Better keep good records all along the way.
How many tests?
There are about 350 pellets in each package, which means each tube holds about 70 pellets. How many tests can be done with that many pellets? For starters, don’t assume there will be 70 pellets in every tube. Assume there are fewer than 70 in some tubes. Next — how many pellets do you plan to shoot for each group? How many guns will you be testing these in? What distance will you shoot at?
Test design is done backwards. You first need to determine what you desire to find out. That’s a lot more specific that just finding out which pellet is the most accurate, because in some guns it might be one pellet while in other guns it might be a different one. That tells you that you need to test these pellets in more than one gun. You also might want to identify a lot that just doesn’t work in any airgun. That’s as valuable as finding out what works.
There are a lot more variables involved in this test than just the guns, but I won’t discuss all of them right now. It’s safe to say that 70 pellets aren’t enough for a large test. So, instead of 10-shot groups, I will be shooting 5-shot groups with each pellet from each gun. How many groups can I shoot? Five goes into 65 (I reduced the number 70 by five because I don’t know if all tubes have 70 or more pellets) 13 times. I can shoot 13 five-shot groups with the pellets I have. What does that give me?
Well, I can shoot 13 different guns, one group each, at one distance, or I can shoot 6 different guns, one group each, at two distances. But, if I want to return to a specific pellet and shoot a 10-shot group for some reason, then the number of guns, groups and distances I can shoot is reduced. Do you see how complex this becomes when you plan it this way? However, if you don’t plan it this way before you start, you will invariably finish the test wishing you could do more testing of one or more factors.
I haven’t even gotten into all the other variables you have to track to make this test worthwhile. I will record them and report them in the test as it progresses.
Based on the number of pellets I have, I am going to try to test these pellets in 4 different air rifles. All 4 will be accurate rifles. Today I will begin testing with the Beeman R8, which is an old-style Weihrauch HW 50. It’s not the HW 50 of today, but the one Weihrauch made 40 years ago. I have some other rifles in mind for future tests, but today it’s the R8.
I will shoot one group of 5 pellets from each of the 10 lots. That’s five groups with 4.50mm heads and five with 4.51mm heads. I will shoot from 25 yards with the rifle resting directly on the sandbag. I know from experience that the R8 likes to be rested directly on the sandbag for best accuracy. It also eliminates a lot of my own movement.
All of today’s targets were hung upside-down. I cut each 12-bull target in half to fit my pellet trap and today I used the bottom halves of the targets that I hung upside-down. All targets are pictured in the same orientation that they were shot.
The Beeman R8 I was testing them with shot them at an average 569 f.p.s. which is an average 6.88 foot-pounds/ 9.33 joules. That’s for future reference.
I show a pellet in every photo of a target. I used the same pellet for all 10 photos because frankly you couldn’t see any difference. These are all the same pellet.
The R8 I’m using for today’s test put five JSB Exact RS pellets into 0.092-inches/2.34mm at 25 yards in 2010. It’s one of my most accurate .177 rifles.
Start — 4.50mm heads
First up were the five lots of pellets that had 4.50mm heads. I will show the groups from all five lots and then discuss them. The test was conducted on February 8, 2019. The temperature was 68 degrees, F/ 20 degrees, C, and the test was shot indoors.
This is lot 1 of the 4.50mm heads. The coin is an American dime that measures 17.9mm across. This group of five measures 0.759-inches/19.28mm between the centers of the two holes farthest apart. The number above the target is from the label on the tube. It correlates to the lot number of this pellet head size, so I can track things.
Five pellets from lot 2 went into 0.514-inches/13.06mm between centers at 25 yards.
Now, this is interesting. Three pellets are in the hole on the left and two in the hole on the right. I watched them go into those holes. The entire group measures 0.373-inches/9.47mm between centers.
Lot 4 is 5 pellets in 0.258-inches/6.55mm at 25 yards. This is the smallest group with pellets having a 4.50mm head.
Lot 5 gave another group of three in the left and 2 in the right hole. This group measures 0.521-inches/13.23mm between centers at 25 yards.
Discussion of the 4.50mm head
Now that all five lots have been shot we can see some things. First we see that some of the pellets want to group well and others do not. Lot 1 gave a very open group, as did Lot 5. Lots 3 and 5 both had three pellets in one group and 2 in the other. And, in both cases, those holes were left and right.
Lot 4 gave the smallest group. It’s about one-third the size of the Lot 1 group. It’s not as small as the group I showed from 2010 with JSB Exact RS pellets, but all that means is this rifle likes that pellet better.
Don’t fret the thousandths of an inch! The edges of the holes made by domed pellets are extremely difficult to determine, so there is some error in the measurements. What can be determined are the gross relationships — Lot 4 is clearly better than Lot 1, but there may not be much difference between Lots 3 and 4. With this little data not much can be said for certain. We are just beginning to get a feel for this pellet in this rifle.
Last observation — are you as impressed as I am by the difference in the same pellet by different production lots? We have no way of knowing what went into each lot, but by examining the Lot 1 and Lot 4 targets we can definitely see a difference in performance.
Now we will move to the other pellets — the ones with 4.51mm heads. Other than the head size, all test conditions remained the same. These pellets were also packaged by lot number and will be discussed that way.
Lot 1 of the pellets with 4.51mm heads grouped five pellets in 0.423-inches/10.74mm at 25 yards.
Lot 2 of the second group measures 0.556-inches/14.12mm between centers at 25 yards.
Lot 3 grouped five in 0.422-inches/10.72mm at 25 yards.
Lot 4 grouped five pellets in 0.712-inches/19.59mm at 25 yards.
Lot 5 put 5 pellets into 0.603-inches/15.32mm at 25 yards.
Discussion of the 4.51mm head
There were no two-hole groups with this pellet, but three of the five targets did have one pellet that didn’t stay with the others. Just looking at how open these groups are leads me to believe this rifle does not like the 4.51mm head as well as it does the 4.50mm head. I’m inclined to think this rifle is better suited to the 4.50mm head than the 4.51mm head.
Discussion of today’s testing
While a lot of data has been gathered today, we know very little about any of these 10 pellets. That’s because they were only tested in a single rifle. If we were looking for the best of the 10 for this rifle, the choice would be much simpler. But we’re not. We are looking for the best one or two pellets of the 10 in this test. And when you are testing a pellet, the results are open-ended. No matter how much you test, there will always be something more that could be tried.
The next test will be like this one, but with a different rifle. If we are lucky there might be some things that start to emerge from that test. They may not be good things, like an extremely accurate pellet. We might start finding out which lot is a poor pellet in most airguns. That’s also good to know, even though it doesn’t sound like it.
Are you bored yet? That’s my fear — that you will get mired down in the data and forget what we are trying to do. I’m trying to test a single pellet that has been supplied in five different lots of 2 different head sizes. And, I am testing with a very small quantity of each lot of pellets. I shot 70 of a total of 700 pellets just today.
Test design is a matter of stating the desired outcome and then planning backwards from that. When you know what you want to find out you can plan how to get it. The desired outcome isn’t the same thing as the results. You don’t want to predict the results of the test, or you may introduce bias into your test designs. For the test we are conducting now the desired results are, 1. Is this a good pellet for air rifles running at 12 foot-pounds and less? And, 2. Which lot is the best, or is there more than one? A third result might be — does testing indicate that pellet head sizes seem to be important?
One thing I have not done that is essential to a good test. The test plan and each test design is subject to peer review. In other words, more than one person looks at what is planned. However, I have no doubt I will get a good and very thorough review from you readers, and we will all learn something in the process.