Testing the .177 Pelletgage: Part 5

by Tom Gaylord
Writing as B.B. Pelletier

Before we start today’s blog, I wanted to remind you that we changed how to post a comment or reply to a comment on the blog. This was done mid-morning yesterday. If you’re having issues logging in or don’t know how to create an account, please email Edith ([email protected]) for assistance.

Part 1
Part 2
Part 3
Part 4

Pelletgage
The .177-caliber Pelletgage. The holes are in a steel plate. A plastic plate above the gage plate helps guide the pellet head to the gage hole.

This report covers:

  • The test
  • Pellet 1
  • Pellet 2
  • Pellet 3
  • Conclusions
  • Last comment

Today I’m taking the suggestion of blog reader Alan in Mich., who wondered if an air rifle with less of a pedigree than my TX200 Mark III would also benefit from the Pelletgage. I wondered the same thing, so I tested the Pelletgage using a Chinese B3-1 underlever rifle. Of all the air rifles around, this is the one without a pedigree.

I’ve tested this rifle in the past, so I have a baseline on at lest 3 pellets. Of them, 7.9-grain Crosman Premier lite pellets did the best. The full report is here.

Premier lite target
This is the best target (about 1.50″) obtained in the test of the B3-1 in 2010. This target is the same size as the targets below, but the image was smaller.

The test

I sorted 7.9-grain Crosman Premier lite into groups with head sizes 4.53mm, 4.54mm and 4.55mm. I gave them to Edith in batches, and she remarked the bags so I wouldn’t know which pellet was which.

I shot from a rest at 10 meters. I used a 10-meter pistol target, the same as was used in the report about the rifle. The B3-1’s open sights are very clear, so aiming wasn’t a problem. And the artillery hold was used throughout the test because the rifle does kick and vibrate.

Pellet 1

The first pellet I used went into the bull on the first shot, so the rifle was still sighted-in. Ten shots went into 1.19 inches at 10 meters. The group is very open. All shots released perfectly, so this group is what the rifle does with this pellet.

Crosman Premier lite target B
The first pellets, labeled “B” went into 1.19 inches at 10 meters. The head size is 4.53mm.

Pellet 2

The second pellet I tested put 10 into a group measuring 1.273 inches between centers. Again, every release (break of the trigger) was perfect.

Crosman Premier lite target 5
The second pellets, labeled “5” went into 1.273 inches at 10 meters. The head size of these pellets is is 4.54mm.

Pellet 3

Ten of the third and final pellets I tested went into a group measuring 1.431 inches between centers. This is the largest group of the test. As with all the other shots, every release was perfect.

Crosman Premier lite target X
The third pellets, labeled “X” went into 1.431 inches at 10 meters. The head size of these pellets is is 4.55mm.

Conclusions

These groups are pretty much what I got back in 2010, give or take a little. I have to conclude that there are cheap pellet guns for which the Pelletgage will not make a significant improvement. Of course, this is just one test, and more testing might reveal things not seen here.

I guess the bottom line is that if you’re shooting a gun that’s not so good, don’t waste money and time trying to make it shoot better. Shoot the cheapest pellets you can find and be satisfied with the results. But that doesn’t mean the Pelletgage can’t help you with low-priced airguns, too. There are plenty of budget airguns around that can probably benefit from its use, and I plan on testing some of them next.

Last comment

Before I finish, perhaps some of you are wondering if today’s large groups are partly my fault. I know I did! After shooting the three 10-shot targets you see above, I shot another 10 shots from a different .177 breakbarrel air rifle that isn’t on the market yet. This one is also a budget airgun, though not quite the $20-$30 that the B3-1 was. It has open sights similar to those on the B3-1.

The details of this rifle are secret for now, and this was the first time I’ve ever shot it, so I had absolutely no idea which pellet to use. I just grabbed a tin of Air Arms Falcon pellets and started shooting.

I also shot this rifle from the same rest at 10 meters using the artillery hold. The group I got measures 0.508 inches between centers — so apparently old B.B. can still shoot. I hope this rifle comes to fruition. If it does, it’ll be a best buy that I’ll strongly recommend.

mystery rifle target
Ten pellets in 0.508 inches at 10 meters proves that B.B. can still shoot an airgun! Had the B3-1 done something like this, I would have been dancing in the street!


Testing the .177 Pelletgage: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3

Pelletgage
The Pelletgage comes in .177 caliber at the present. The holes are in a steel plate. A plastic plate above the gage plate helps guide the pellet head to the gage hole.

This report covers:

  • Description
  • The difference is obvious!
  • Head sizes
  • Every shot was perfect

The last test I ran on the .177-caliber Pelletgage (reported in part 3) was unintentionally flawed. I wasn’t sure at the time, but when my results were muddled and I examined the test plan, it was easy to see.

Description

The Pelletgage is a device that measures the diameter of pellet heads, so they can be sorted into groups of similar sizes. Pellets that come in the same package often have a range of different head sizes.

We know pellet head sizes matter to 10-meter target shooters; and Pelletgage inventor, Jerry Cupples, wondered if that advantage might not extend to all pellet guns. He invented the gage so you can measure the head sizes of pellets down to 0.01 millimeters. Read parts 1 through 3 of this report to see how I’ve tested his device so far.

In part 3, the test was unintentionally constructed with bias. I discovered that 7.9-grain Crosman Premier lite pellets in the cardboard box come in 3 different head sizes — 4.53mm, 4.54mm and 4.55 mm. The predominant head size in the box is 4.54mm. I sorted pellets into groups by head size for the last test, and I shot 4 targets. Two were shot with 4.54mm heads, and the other two were shot with an equal mix of 4.53mm and 4.55mm heads. In other words, 5 of each head size were shot for each group. That was the bias in my test plan.

I thought that a group shot with pellets of equal size (4.54mm) would be demonstrably smaller than a group shot with pellets having two different head sizes (4.53mm and 4.55mm). So, I shot two 10-shot groups of 4.54mm heads and two 10-shot groups of an equal mix of 4.53mm and 4.55mm heads. This was all done at 25 yards.

The results of that test were exactly opposite what was expected. The 4.54mm head pellets produced the 2 largest groups, and the two mixed-head groups were the smallest. That lead me to understand that there was probably one pellet of the three that was the most accurate, and it probably had either a 4.53mm or 4.55mm head.

Today, I’m shooting three more 10-shot groups at 25 yards. The test gun remains my TX200 Mark III, which was used in the last test. Today, I’ll shoot one 10-shot group of each head size, with no mixing.

I sorted more pellets using the Pelletgage and then gave three batches of pellets to Edith to put into plastic bags. She marked the bags 1, 2 and 3 and I shot them in that order. All shooting was done with the rifle rested directly on the sandbag, which I’ve determined to be the most accurate way to shoot this particular air rifle. Let’s look at the resulting groups now.

Crosman Premier lite 4.54mm group
This is group 1. Ten pellets went into 0.807 inches between centers at 25 yards.

Crosman Premier lite 4.53mm group
This is group 2. Ten pellets went into 0.241 inches between centers at 25 yards. Yes, there are 10 pellets in that group.

Crosman Premier lite 4.55mm group
This is group 3. Ten pellets went into 0.426 inches between centers at 25 yards.

The difference is obvious!

These groups speak for themselves. Clearly, the pellet used to shoot group 2 is far and away the most accurate pellet. Group 3 pellets made a 10-shot group that is almost double the size of group 2 pellets, and group 1 pellets are much worse. But shoot them all at a target without checking the head sizes first, and the resulting group will probably look okay, even though it’ll be much larger than it could be if only the best group of pellets was used.

Note the small changes in the point of impact as the head sizes changed. Remember folks — these are all the same pellets from a single box! The only difference is their head size, which we wouldn’t know without the Pelletgage.

Head sizes

Now for the head sizes. Group 1 pellets are head size 4.54mm. They are the most common head size in the box. Pellets in group 2 are head size 4.53mm. They are the least common pellets — at least they were this time. Last time I sorted them I found an equal amount of 4.53mm and 4.55mm pellets, but this time it was 2-1 in favor of the 4.55mm heads. That leaves group 3 pellets as the ones with 4.55mm heads.

Every shot was perfect

As I was shooting, I had no idea which pellets were which, so every shot I took was as perfect as I could make it. I could see that the first group was going to be big, but I wanted to be able to tell you that I shot my best, and I did. These results are solid. Of course, they need to be repeated by someone else to gain some credibility; but as far as I’m concerned, they’re rock-solid, and the Pelletgage works as advertised.

I think Jerry Cupples is due some congratulations for what he’s done. He’s given us a precision gage for sorting pellets that really does affect accuracy.

I’m not finished testing this Pelletgage. I want to stretch the range out to 50 yards, and there are still .22-caliber pellets yet to come.


Testing the .177 Pelletgage: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2

Pelletgage
The Pelletgage comes in .177 caliber at the present. The holes are in a steel plate. A plastic plate above the gage plate helps guide the pellet head to the gage hole.

This report covers:

  • Update
  • The test
  • Blind test
  • Interpretation
  • I called it
  • What to make of these results
  • Observations so far

Update

Before I get into the test, I received a message from the Pelletgage maker, Jerry Cupples, telling me that he has measured a large sample of the gages he has made — they’re all measuring 0.01mm smaller than what’s marked on the gage. In other words, a gage hole that’s marked 4.52mm actually measures 4.51mm, and so on. This holds true for all the gage holes in a gage plate.

So, in the last report, all the pellet sizes I gave you were off by the same amount. This is not a problem. All I need to do is change my pellet sizes by reducing all on them by 0.01mm after gaging.

Jerry measured the holes with gage pins traceable to NIST standards. Before that, he was using an optical comparator that might be uniformly off for various reasons — with the edge of the kerf being a prime suspect.

I’ll continue to use my gage, as it’s the uniformity that I’m looking for. I can simply adjust the numbers now that Jerry has informed me. This changes nothing, except how I record sizes.

The test

Today’s test is as different from the last test as I can make it. Today, I shot 7.9-grain Crosman Premier lite pellets from my TX200 Mark III at targets 25 yards away. I know this rifle likes the Premier lite, and I thought this would be a good test for the gage.

Since I have no idea how uniform Premier lite pellets are, the first task was to sort them and see what I got. As it turns out, Premier lites in the cardboard box are very uniform. Most of them had a head size of 4.54mm (yes, that is after I corrected for the gage). But every once in a while, I got one that was smaller or larger. They only differed by 0.01mm each way. At the end of my task, there were 111 pellets with 4.54mm heads, 11 with 4.53mm heads and 10 with 4.55mm heads.

Pelletgage sorted pellets
I found 111 Premier lites with 4.54mm heads, the most common head size. Eleven had 4.53mm heads and 10 had 4.55mm heads. An egg carton makes a good recepticle for sorted pellets.

I decided to shoot 4 10-shot groups at 25 yards off a bag rest. We know the TX200 Mark III does well when rested that way. Two groups would be with the most common 4.54mm heads, and the other 2 groups would be with an equal mix of 4.53mm and 4.55mm heads. There are several ways to ldo this, and today I just wanted to see how uniform pellets did compared to pellets I knew were not uniform.

Blind test

To keep my bias out of the test, I gave the pellets to my wife, Edith, who marked them in bags that I gave her. She knew which bag was which; I did not. As it turned out the results were dramatic and obvious — just not what I was expecting. I have a theory about that which I can test next — thanks to the Pelletgage. But for now, let’s look at the results I got.

I will now show all 4 targets in the order in which they were shot. Then, I’ll discuss what I think may have happened.

Pelletgage target 1 Premier lite
The first 10 Premier lites went into 0.648 inches at 25 yards.

Pelletgage target 2 Premier lite
The second 10 Premier lites went into 0.508 inches at 25 yards.

Pelletgage target 3 Premier lite
The third 10 Premier lites went into 0.654 inches at 25 yards.

Pelletgage target 4 Premier lite
The fourth 10 Premier lites went into 0.625 inches at 25 yards.

Interpretation

Looking at the groups, I don’t see what I expected — which was 2 very small and round groups and 2 groups that were larger. But I do see differences that allow me to place these 4 groups into 2 categories. There are 2 larger groups and 2 other groups that both have small main clusters of shots with one or 2 outlying pellet holes. The second group and the last group have these small clusters.

I know for a fact that, in the second group, the 2 pellets that are not in the main group were fired number one and two in the string. On the last group, I think the one low pellet was one of the first 3 pellets shot, but I’m not sure.

The smaller group in the second target contains 8 pellets and measures 0.253 inches between centers. The small group in the last target contains 9 pellets in the main group that measures 0.286 inches between centers. In the last group, it looks like one shot may have gone between the outlying pellet hole and the main group. That would make the main group 8 shots rather than 9.

I called it

I told Edith that I suspected the second and last targets were shot with pellets having 4.54mm heads and targets 1 and 3 were shot with the pellets that were a mixture of 4.53mm and 4.55mm. She told me I was exactly wrong. Targets 2 and 4 — the targets that contain the tightest groups within the main group — were shot with the mixed head sizes! And groups 1 and 3 were shot with the uniform 4.54mm pellet heads.

What to make of these results

It looks like Premier lites with 4.54mm heads are not the optimal size pellets for my TX200 Mark III. It further looks like either 4.53mm or 4.55mm heads may be the ideal size. This test did not test for that.

If you can think of anything I’ve overlooked, I’m open to your thoughts. My plan is to rerun this test and shoot 3 more 10-shot groups — this time with 10 pellets of each head size — 4.53mm, 4.54mm  and 4.55mm. I hope I have a better idea of what is happening after that.

Observations so far

I’ve now run 2 tests using the Pelletgage, and both times I got demonstrable results. In today’s report, the results were not what I was expecting, but that’s why we test. And the Pelletgage makes testing possible, where before it existed it wasn’t possible to measure pellet heads this precisely. It’s an instrument like a chronograph. No, you don’t need one to shoot airguns and have a good time; but if you want to know more about how your gun works, it’s starting to look like a Pelletgage is essential.


Testing the .177 Pelletgage: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Part 1

Pelletgage
The Pelletgage comes in .177 and .22 calibers at the present.

This report covers:

  • Texas airgun show
  • Today’s test
  • The challenge
  • Qiang Yuan Olympic pellets
  • Time to change direction?
  • Crosman Premier Supermatch
  • A chance to check the pellet skirts
  • Test 1 — youth program pellets
  • Discussion of the 3 targets
  • Coaches — pay attention!
  • Test 2 — Can you test quality into a product?
  • Discussion
  • Summary

Texas airgun show

Before we begin, I want to remind all of you that the Texas airgun show will be held on Saturday, August 29. There’s a link at the top of this blog page that takes you to the show flier for all the information.

On Friday evening before the show, the public is invited to attend a reception at the Texas Star Ranch and Retreat, located near the show. American Airgunner will film an episode of the Round Table and welcome questions from the audience.

We have dealers coming from all over the United States, including some major retailers who will have premium pellets, CO2 and other necessary expendibles for sale. A range will be available all day for the public to try different airguns, and we’re going to host the LASSO big bore airgun competition.

This year’s show promises to be the largest airgun show ever held; and, if last year’s show is any indication, it’ll be well worth attending. Dealer tables are available for $30. Early buyers may also get in before the doors open for the price of one table.

As more information becomes available, I’ll keep you informed.

Today’s test

This test has already become one of the most interesting things I’ve done in the last 10 years. It’s as interesting as my 11-part Pellet velocity versus accuracy test.

The challenge

Today, I’ll consider 10-meter target guns and the pellets they shoot. This may be one of the most challenging tests in the series, because the wadcutter pellets made for 10-meter target shooting are very consistent. I was concerned I wouldn’t find any deviation in pellet head size at all!

Qiang Yuan Olympic pellets

The first pellet I measured was the Qiang Yuan Olympic target pellet that did so well in a recent test. I shot it in my Crosman Challenger PCP target rifle that I also plan to use for this test. And my fears about uniformity were realized! After measuring about 25 pellets and finding them all to have the same 4.51mm head, I stopped measuring. I could be there for hours before finding even one different head. I had to try something different.

This is the problem I had feared from the beginning. Match pellets are all very uniform, so they shouldn’t really vary at all. What could I do?

Time to change direction?

I thought I might switch horses in midstream and test domed pellets at 25 yards, but that didn’t go well, either. I looked at Air Arms Falcon pellets, which are supposed to have a 4.52mm head. After measuring 21 of them I had 20 that were head size 4.51mm and one that was size 4.50mm. None measured the 4.52mm that’s marked on the tin.

Falcon pellets sorted
Out of 21 Falcon pellets measured, only one had a head that was not 4.51mm. Below is a short video showing you how I measured the Falcons:

Clearly, premium pellets other than wadcutters have uniform heads, as well. So, I rethought the test. I still wanted to test 10-meter target rifles and pellets, and I thought of a way to do it. In fact, this was the ideal test to conduct.

Crosman Premier Super Match

Many youth shooting clubs use target pellets given to them by both Crosman and Daisy. Both companies are huge supporters of youth marksmanship programs. I had a fresh tin of Crosman Premier Super Match pellets on hand. These pellets sell for very little money (for target pellets), so I wondered how consistent their heads could be. And I had the perfect instrument to find out!

As it turned out, Super Match target pellets had heads that were sized either 4.50mm or 4.51mm, and the distribution of both sizes in the tin was about equal. That lead me to construct the first test. I sorted a total of 30 pellets and put them into 3 labeled containers. There were 10 4.50mm pellets in one container, 10 4.51mm pellets in another container and 5 of each head size in a third container.

Crosman Super Match distribution
Crosman Super Match pellets came in 2 head sizes and nothing else.

I would shoot three 10-shot groups at 10 meters to see what happens. First, we’ll see if the Challenger PCP has a preference for pellets with 4.50mm or 4.51mm heads. Second, we’ll see how a mix of both head sizes does. That will represent picking pellets from the container at random.

Ten meters is extremely close for any irregularities to show up. I know I’m shooting 10-shot groups, but to convince me that sorting head sizes is necessary, there will have to be a visible difference in the group sizes — one that can be attributed to something other than a measurement error.

A chance to check the pellet skirts

Before I packaged them for testing, I looked at each pellet skirt critically. As all the pellets were standing skirt-up, I took a tactical flashlight (a very bright light) and shined it at an oblique angle while I examined all the pellets. There were 32 pellets that had been measured, and one of them had a flat spot on its skirt. I disposed of that pellet and put the one extra pellet back in the tin after putting the 30 sorted pellets into 3 marked containers.

Test 1 — youth program pellets

Next, let’s shoot these 30 pellets and see what we get. The range is 10 meters, and I’m shooting off a sandbag rest. I don’t care where on the target the pellets go — just how close to each other they hit.

Crosman Premier Super Match Target 1
This first target shows where 10 Crosman Super Match pellets with 4.50mm heads landed at 10 meters. The group measures 0.485 inches between centers.

Crosman Premier Super Match Target 2
This second target was shot with 10 Super Match pellets that have 4.51mm heads. It measures 0.144 inches between centers.

Crosman Premier Super Match Target 3
This third target was shot with an equal mix of Super Match pellets having 4.50mm and 4.51mm heads. These 10 pellets went into 0.282 inches at 10 meters.

Discussion of the 3 targets

Clearly, there’s a big difference between the results of the 4.50mm heads and the 4.51mm heads. There’s also a significant difference between the 4.51mm heads and the target that was shot with an equal mix of 4.50mm and 4.51mm pellets. That target represents what will happen when the pellets are taken directly from the tin without regard for the head sizes. Right there, youth shooting program coaches can see point gains of 5 points per match per shooter! And I’m being extremely conservative with that estimate. Your best shooters will gain close to 10 points per 40-shot match by shooting pellets with the correct head size.

Now, for the tough question. Why is the group of 4.50mm pellets larger than the mixed group? I can’t tell from these few results. If I had to guess, I would say that while 4.50mm pellets are less accurate, some of them do go to the same place as the 4.51mm pellets. Just not all of them, which is illustrated by the first target. There were absolutely no called bad shots in this test. All shots broke with the bull centered in the front sight aperture.

These results are from one specific Crosman Challenger PCP target rifle. Other rifles, including other Challengers, may prefer the pellets that have 4.50mm heads. This is something that has to be tested to know for sure.

Coaches — pay attention!

Many of the 74,000 youth shooting programs in the United States are given free pellets by Crosman and Daisy. If they’re not completely free, they’re supplied at a very low price — so low the clubs cannot afford to ignore them. This test has just demonstrated how to take these bargain pellets and turn them into something that will make more points for your shooters. If I were involved with a youth shooting program of any kind that used these pellets, I would get a Pelletgage, post haste!

Test 2 — Can you test quality into a product?

Now we come to the big question — the one most of you have been pondering, myself included. Can non-premium pellets be sorted with the Pellegage into batches of superior pellets? I didn’t know, and after my experience measuring the very uniform Crosman Super Match pellet (it was far more consistent than I was expecting), I knew I had to go way down the quality scale to find a suitable pellet, i.e. one that has pellets with heads of multiple sizes in the same tin. I did find one.

This pellet is an Industry Brand pellet that is made in China to dubious quality standards. I keep this tin in my junk pellet drawer, thinking maybe a day will dawn when I need 500 split-shot sinkers for fishing. You get the picture. These aren’t pellets I ever shoot.

I started sorting these pellets and got some dramatic results — the results you were probably expecting from this test — I sure was. The head sizes were all over the place. They ranged from 4.51 to 4.56mm. After I got them grouped on a paper by size, I saw what was happening. It looks to me like the Chinese plant was using several dies to make these pellets. Some of the dies were new and others were old and wearing out. But they just dumped the entire output from all the dies into a single bin and then packaged all the pellets from that one bin. At least, that’s what it looks like.

Let’s see if we can sort these pellets into quality batches by head size. Most of the pellets had a 4.55mm head, so I kept sorting until there were 10 of that head size and 10 more with head sizes ranging from 4.51mm to 4.56mm (but no 4.55mm heads). That gives me 2 groups of pellets to test in the rifle — one with all their heads the same size and the other with heads of mixed sizes. I don’t care whether or not 4.55mm heads work well in the Challenger. I’m interested in seeing how pellets with mixed head sizes compare to the same pellets with a single size head. If head size matters, this test should bring it out. The group shot with mixed head sizes should be significantly larger than the group shot with identical head sizes.

Industry Brand distribution
I used most of the gage holes for these Industry Brand wadcutters. Though only nine 4.55mm pellets are shown, I gaged another one for the test.

Industry Brand Target 1
This target was shot with Industry Brand pellets having a consistent head size of 4.55mm. It measures 0.323 inches between centers.

Industry Brand Target 2
This target was shot with Industry Brand pellets of various sizes — from 4.51mm to 4.56mm. It measures 0.314 inches between centers.

Discussion

The results of this test surprised me. I expected the pellets with varying size heads to do worse than those that were consistent. My interpretation, which doesn’t have enough data to support it, is that 4.55mm heads are so wrong for this rifle that even variable sizes are not worse. I would have to shoot many more targets with Industry Brand pellets of consistent smaller sizes, and I would think the 4.51mm head size might do best. But that’s just conjecture, and I’m not going to test it, because there aren’t enough smaller-sized pellets in the tin. I do plan on testing uniformity versus variable-sized heads in a later test when conditions are more favorable.

Summary

Well, I certainly learned a few things today. First, I learned that many name brand pellets are more uniform than I thought. I expected the premium 10-meter pellets to be uniform, but not the other ones. As you read, I really had to search to find a pellet with variance. That tells me that sorting by head sizes isn’t necessary when you shoot premium target pellets. I don’t expect World-Cup 10-meter competitors to use the Pelletgage.

I didn’t know if 10 meters was far enough to discern differences between the consistent pellets and the pellets with mixed head sizes. But the first test proved that it not only was far enough — it actually makes a huge difference when you use the right pellet in a Sporter-Class target rifle like the Crosman Challenger PCP. I would expect to see similar results with the AirForce Edge and the Daisy Avanti 853, but neither of those rifles is available to me.

Next, I learned that my Challenger prefers pellets with 4.51mm heads. The Qiang Yuan pellets that it shot so well during that test have a 4.51mm head (all of them!), and the best target shot with the Crosman Super Match pellets was also with the 4.51mm heads. So, I think this rifle is telling me that it likes pellets with 4.51mm heads best.

Today’s report took me 2 days to complete. There was the measuring and sorting, the photography the shooting and of course the writing. I’m telling you this so you’ll understand why I have to space these reports out a bit. There just isn’t enough time to do them as fast as I would like.

I am done at 10 meters. The next test will be shot from 25 yards with a more powerful spring rifle.

I consider this the start of one of the most important test series I’ve ever done, because today’s results suggest the Pelletgage works very well. If things continue in this direction, this will be the most important invention airgunning has seen in a decade.


Testing the .177 Pelletgage: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

Pelletgage
The Pelletgage comes in .177 caliber at present. The holes are in a steel plate. A plastic plate above the gage plate helps guide the pellet head to the gage hole.

This report covers:

  • Introduction to the Pelletgage
  • How it works
  • How can the Pelletgage be used?
  • How accurate is the Pelletgage?
  • There is a technique to measuring
  • Is the Pelletgage necessary?
  • What comes next?
  • Where to get a Pelletgage

Introduction to the Pelletgage

The Pelletgage is a precision tool that lets you measure the pellet head sizes. The device is a metal plate with graduated holes that accept or reject pellet heads. If a hole accepts a head, the pellet falls through and will usually be caught on the skirt that’s wider than the head. The holes range in size from 4.47mm to 4.56mm.

The Pelletgage does not change the size of the pellet. That is not its function. It measures the pellet head size so you can be sure they’re consistent.

Pellet rejected
This pellet’s head is larger than 4.49mm. Photo provided by Pelletgage.

Pellet accepted
This pellet’s head (same pellet as above) is 4.50mm. Photo provided by Pelletgage.

How it works

You drop the pellet head-first into the hole you wish to use. The instrument has a plastic plate above the precision steel gage plate to help guide the pellet head. If the head drops through the hole in the steel gage plate, you know that the pellet head has got to be smaller than that hole. I start with a small hole and work up. For instance, if I’m measuring a pellet that’s supposed to have a 4.51mm head, I’ll start with the 4.50mm hole. If the head doesn’t drop through, I move up to larger holes until it does. The first hole it drops through is the head size.

If I don’t know the head size of my pellet, I start small and gradually increase until I find it. For example, I discovered that .177 RWS Superdome pellets have 4.51mm heads, according to my gauge. And I also found they’re very uniform. I measured 10 pellets for this report, and all 10 failed to pass through the 4.50mm hole but did pass through the 4.51mm hole.

You might think that will happen with every pellet, so I also tested H&N Baracuda Match pellets that are supposed to have 4.52mm heads. They were also very uniform, but the gage measured their heads at 4.54mm instead of 4.52mm. More on that in a moment.

Superdomes gaged
I gaged 10 RWS Superdome pellets and they all had 4.51mm heads. That’s uniformity.

I then measured 10 .177-caliber Beeman Devastator pellets. Three of them measured 4.51mm, four measured 4.53mm and the last three measured 4.54mm. None measured 4.52mm. From 4.51mm to 4.54mm is a wide variation! We need to give that that some thought. More on this in a bit.

Beeman Devastators
When I gaged 10 Beeman Devastator pellets, they had 3 different-sized heads. None of them had a 4.52mm head. This variation is much larger than I would have suspected before using the Pelletgage.

How can the Pelletgage be used?

1. Sorting pellets by head size. We know that pellet head sizes affect accuracy, so sort them with the Pelletgage to find pellets with the same size head. Yes, some tins say the pellets inside have heads that are all one size, but with the Pelletgage you’ll know for sure. Combine this with sorting each pellet by weight. Think this is going too far? I can tell you with certainty that this is exactly what the champions will do. Those who don’t do things like this are usually the also-rans.

2. Finding the head sizes of pellets whose sizes are not marked on their containers. I have already done this with RWS Superdomes mentioned above, and now know they have heads that measure 4.51mm — according to my gage. If you have an airgun that prefers pellets with certain-sized heads, the gage is a way to discover potental candidates without shooting every pellet in your inventory.

3. Verifying the head size that’s marked on the tin. I’ve already told you I have H&N Baracuda Match pellets whose heads are supposed to be 4.52mm. The gage says they’re 4.54mm. It also says their heads are very uniform. Okay, I know that my gage doesn’t agree with the head size measurements from H&N. That really doesn’t matter to me, but it’s nice to know. Is the gage off a bit? Maybe so, but is it off as much as 0.02mm? Probably not, as you’ll shortly discover. The equipment that was used to make the gage is far more precise than that. I will just tuck that piece of information in my head for now and see if it ever becomes important.

4. Comparing one tin of pellets to another tin of the same pellets. As pellets are made, the dies that swage them wear. Eventually, the die cavities open up and the dimensions of the pellets change. Do the pellets in the tin you just bought have the same size heads as the pellets you bought a year ago? The Pelletgage will tell you.

How accurate is the Pelletgage?

Accuracy in a precision measuring tool is always a concern. First of all, let me address those who believe they can measure pellet heads with a micrometer or a caliper. No, you can’t. Those tools do not have the ability to find the exact chord (the diameter of a circle — its widest point) of the small pellet head each and every time. The pellets can tip in their jaws and the jaws can also hit the rims of the pellet heads off the mark of the true chord by a few degrees, measuring something less than the full diameter.

These measuring instruments also close their jaws with some force that can too easily flatten thin diameters of soft lead pellet heads. I admit the latter is not a great concern for a machinist who measures things with precision all the time, but it’s a concern for the amateur who isn’t that familiar with measuring things.

The former — finding the exact chord of a small thin circle of soft lead — is hard no matter who you are or what you do for a living. The Pelletgage eliminates the need for finding the chord.

I can tell you that the Pelletgage is manufactured with a diode-pumped fiber laser using oxygen process gas to produce cuts that are very smooth. This laser cuts to an accuracy of better than 10 microns (one micron is one-millionth of a meter and one-thousandth of a millimeter) with repeatability. Still, the Pelletgage maker, Jerry Cupples, is concerned with the accuracy of the finished gages.

I’m not concerned with the Pelletgage’s accuracy. If I were a pellet manufacturer who was using a Pelletgage to put the head sizes on my tins of pellets, then I would be concerned if the gage measured exactly 4.51mm. But as a user of the gage, I’m more concerned with the consistency of the pellets I measure.

Now I’ll address those things I mentioned earlier, but postponed discussing. Am I concerned that my gage’s measurement of a 4.54mm head for the H&N Baracuda Match pellet disagrees with the H&N labeling of 4.52mm? Not to me, it isn’t. What would concern me is if I got pellets with 3 different head sizes from that tin. The fact that my gage doesn’t agree with H&N’s size labeling is of no concern to me.

So, my results with measuring the H&N Baracuda Match pellets doesn’t bother me. What bothers me is the fact that Beeman Devastator pellets came from one tin with 3 different head sizes that spanned 0.04 millimeters.

There is a technique to measuring

We’re talking about such small tolerances that the pellets do not automatically fall into the gage holes — even with the clear plastic guide holes. A technique has to be employed. I had to wobble the pellet around the gage hole lightly to get it to line up. I worried about wearing the edge of the pellets’ heads by doing this, but I used an extremely soft touch. I don’t know if I caused any wear, but I was able to take a pellet of a known size back to the gage repeatedly, and it never measured any smaller from wear to the edge of its head. So, I think I’m doing it right. Time will tell.

Is the Pelletgage necessary?

You’ve lived this long without one. How necessary is the Pelletgage? If you’re a plinker who’s content to reach into a tin of pellets and pull out the next one for your gun — kinda like me — then you don’t need a Pelletgage. If you’re a field target competitor who hopes to win a match, this might be something to consider. If you’re a 10-meter competitor who shoots in national competition like I used to, then you almost have to check out this instrument.

We’re just starting to know this tool, so its importance cannot be accurately estimated at this time. I can make a case for this being the most important advancement in airgunning in the past decade, and I can also make the case that this tool is not required. Until I have a chance to test it thoroughly and learn what its benefits are, I won’t know anything.

I can see vast potential for precision with this gage. I almost hope it doesn’t turn out that way, though, because it would muddle so much of the testing work I’ve done to this point in time. My guess is the Pelletgage will end up being somewhere in the middle. It will make a difference for some kinds of shooting, but not for all of them. There will be some folks who will swear by it and other folks who won’t give it a second thought. I plan to test the Pelltgage to find out who those folks should be.

What comes next?

I need to find ways of testing this gage. While that might sound straightforward, I assure you it isn’t. I’m working on a test plan at this time and welcome your thoughts and input.

Where to get a Pellegage

You can get a Pelletgage at Pelletgage.com. There will be a .22-caliber Pelletgage coming soon.