GTA
All Springer/NP/PCP Air Gun Discussion General => Air Gun Gate => Topic started by: Zoey on April 22, 2017, 09:58:20 PM
-
I haven't been a "serious" AG shooter for very long, but I've been around long enough to know that many of you are on what seems to be a never ending quest to find the perfect pellet for your gun. This post will be an ongoing process, and as I progress through this journey, I will add more information/results. I encourage the members at large to contribute to my expedition by making helpful suggestions and questioning my methodology.
I thought I would share with you my journey and my findings along the way.
First, a little background:
This will not be absolutely scientific. I did not take statistics in school, and my background is in emergency medicine. Therefore, please don't expect large math equations and graphs.
All shooting will be done with an AGT Vulcan Gen4 5,5 (.22cal) Bullpup sporting a Schmidt Bender PMII 6-24x56 scope. Shooting will be off of a bubble-leveled Bald Eagle front stand and a rice filled rear bag. Gun cant will be marginalized by a Flatline Ops bubble level. Testing will be completed in an indoor range at a distance of 23 meters, and verified by laser range finder. Confirmation of zero will be completed prior to each day's shooting. There will be only one shot per bullseye. Pellets will be JSB Exact Jumbo Heavy Diabolo 18,13gr.
Where I started
(http://i.imgur.com/WyCqR4e.jpg)
If I'm honest, I chose the JSB Pellets simply because the Vulcan shooters indicate that they, and the AA Diabolo Field's, were the most accurate in their guns. I ordered a tin of the AA's, and was somewhat disappointed with the results. In addition, the skirt is much more thin on the AA's when compared to the JSB's. Because of this, a lot of pellets arrived to me damaged.
I do realize that at the end of the day, the JSB may or may not be my gun's true love. However, without testing, I will never know.
The first step in the process was to wash and dry the ~1000 pellets. They were carefully placed in a plastic container with a small amount of Dawn wash up soap and hot water. They were gently swirled for a few minutes, and then thoroughly rinsed with hot water. The pellets were then put on a cloth towel and completely dried with a hairdryer.
(http://i.imgur.com/YhWiXRb.jpg)
Following a good washing, the pellets were divided by head size using a PelletGauge. Pyramid Air indicates that their JSB pellets have a head size of 5.52. However, here are the sizes I found to be within two tins:
5.50
5.51
5.52
5.53
5.54
5.55
After head measuring, all of the pellets were segregated by size for the next step:
*NOTE: I purposely did not lubricate the pellets prior to the next step. I found that the lubricant caused the pellets to stick to the glass, and not roll consistently.
The tabletop "device" in the photo above is what I am using to Yrrah roll the pellets. It's actually a glass framed photograph in which I have taped two rulers to. The red ruler is to insure that I always start the roll at the same place, and the bluish ruler is to determine where the pellet stops. Once I figure out what size and head-to-skirt ratio is the best, I will build an actual table with the exact same dimensions. *TIP: a glass top is great to write on with a dry-erase marker.
To further explain the Yrrah method, I place a pellet on the glass top with the skirt facing me. Each pellet is placed on the exact same ruler marking (red & white ruler), and both the head and skirt are touching the ruler before letting go of the pellet. Any pellet that rolls away from the ruler askew is re-rolled.
The pellet then rolls in an arc due to the difference in head-to-skirt size, and stops at the bluish colored ruler. Where the head lands in relation to the ruler markings determines its segregation.
The "Yrrah table" is set to a 1º angle. I chose this as it is just enough to get the pellet rolling (in most cases), yet not so steep that the pellet slides on the glass.
Each pellet was Yrrah rolled and subdivided by final roll length. Any that fell out of the low or high-end of measurement were rolled a minimum of three times until a consensus was obtained. In addition, defective pellets (e.g. bent skirt, oblong, excessive short/long roll, "odd" sounding roll) were removed from the bunch.
(http://i.imgur.com/03WBKTM.jpg)
After rolling, I ended up with 177 defective pellets (17.7%). By only a slight margin, damaged skirts were the most prevalent cause of elimination. The other major causation was head-to-skirt ratio being far too large or small.
(http://i.imgur.com/QQ7DDXj.jpg)
Here are the results of about 6 hours of "fun".
The final step before shooting was to lubricate the pellets.
(http://i.imgur.com/pwvDZbq.jpg)
I had intended to use Powerpel Pellet Lube, but obtaining it stateside (and at a reasonable price) proved to be problematic for me. As an alternative, I decided to try "White Lightning Clean Ride" (WL) bicycle chain wax lube. After shooting around 500 lubed pellets, I can report that my barrel does remain much cleaner than shooting out of the tin. It does seem to improve accuracy, but only slightly. Gone are the days of black-coated fingers, and my chronograph shows an increase of 16fps with JSB Exact Jumbo Diabolo 18,1gr pellets.
The WL was transferred into an eye glass cleaning solution bottle. This bottle produces a nice fine mist. The foam pads of an empty pellet tin were liberally sprayed with WL and a small portion of pellets were added to the tin along with the foam pads. After putting the pellets into the tin, they were sprayed with one pump of the WL. The tin was then gently rolled for approximately 1 minute. *Note: it's important to shake the WL bottle prior to each use as it will separate quickly.
The pellets were then transferred from the tin into labeled plastic bags. The bags were left open in order to allow the WL to off-gass for 30 minutes prior to closure.
In my next post I will be reporting on the results of shooting. Most likely, I will only get through one head size per update. I haven't decided how many pellets of each group I should shoot, and some of the groups have but a few pellets.
Cheers!
-
Nice work! Damaged skirts cannot be good for accuracy. One day when a hundred other things (and continually being renewed) are done, I would like to make a device to swage pellet skirts for accuracy.
-
I personally don't wash & lube JSBs & H&N Baracuda Match, because they're pretty much clean & dust free right out of the tin. Sorting out any damaged ones, yes.
Now Eun Jins are another subject when it comes to washing.
-
I was surprised to find that slightly obround skirt on a JSB pellet has no discernible effect on groups out to at least 50 yards.
For pellets with thick skirts and/or harder alloys, I do see a velocity loss when the skirt is deformed.
-
I applaud you effort and the meticulous nature of your experiment. However, I can'd find any reason for myself to sweat going through pellets- simply because I don't really shoot over 40 yards ever, and only rarely go over 30, and most of my plinking and pesting is under 25 yards!
Having said that, I still go through my pellets to find the most accurate upon purchase of the airgun, and I routinely "double-check" results. I try to find 3 pellets that shoot well, and use the most accurate for pesting and the others for plinking- mainly because I only take headshots. Sometimes what works most accurately at one range really opens up if I go much further. RWS Meisterkugelns WC are a good example. At 20 yards, they are The Pellet in my 760 pumper at 10 pumps (it has a rifled barrel), but at 30 yards, they open up more than 2 times the group size! Coal Fenix domes, JSB Exact Heavies, and JSB UltraShocks. The interesting part is the Coal Fenix domes shoot the same group at 20 and 30 yards. Obviously, some of that is me. :D
So what works at one range should be tested at other ranges for consistently, though I'm betting pellet velocity and ballistic coefficient also has a major role. The JSBs and Coal Fenix pelletsa have a much higher BC than the RWS Meisterkugeln WC, and I think my other-stock760 pumper just doesn't have enough "oomph" at longer ranges to keep groups tight!
The most consistent pellets I've shot the times I actually measured were Beeman Silver Arrows (for my PP700) and my .25 Polymags for my Model 95QE. No damaged skirts in the tins, minimal swarf, negligible weight variance, and clean Clean CLEAN!
And at the range I'm putting pellets on-target, the accuracy isn't affected at all. Now, if I was shooting in an FT match, I'd be spending some time sorting, cleaning, weighing, and going through the steps you're taking, because- to be competitive, I'm sure I would need every single advantage I can devote the time for...
but for the shorter range pesting and plinking I do, it would be a lot of effort for no gain at all, and I already don't have enough free time :( :-\
-
Damaged skirts cannot be good for accuracy
Hang around my friend. I will be shooting the "damaged" pellets to test accuracy. Time to find out if I've been tossing damaged pellets into the recycle bin for no reason.
I personally don't wash & lube JSBs & H&N Baracuda Match, because they're pretty much clean & dust free right out of the tin.
I'm not sure what JSB uses to lube their pellets, but I seem to get "graphite fingers" after a day of shooting. With the WL, I no longer have that issue. When washing the pellets, there is a bit of swarf in the bottom of the wash up container, but not a horrible amount.
I was surprised to find that slightly obround skirt on a JSB pellet has no discernible effect on groups out to at least 50 yards.
For pellets with thick skirts and/or harder alloys, I do see a velocity loss when the skirt is deformed.
Ooh! You just gave me an idea. Prior to shooting the damaged pellets on target, I should chronograph a few examples of each type of typical damage. Thanks!
@Anti-squirrel: You make a very valid point about a pellet being accurate at one distance, but not another. It's something I will need to examine in the very near future.
-
The JSBs do have a graphite coating.
-
I assumed that's what it was, but then again, it might be some super secret magic pellet coating. ;D