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Field Target Tech Channel Episode #5 TR Robb Pellet Sizer

January 6 2018 at 8:51 PM
Tom Holland   (Login xbowsniper)
YF12

In this episode of Field Target Tech Episode #5, I describe how to use the TR Robb pellet sizer properly and how to set it up as well.

https://youtu.be/iJo1assKEXE

Tom Holland
Sniperxbow60x@aol.com
Assistant Match Director
Eastern Suffolk Competitive Airgunners Association (ESCAA) escaaclub.com


    
This message has been edited by xbowsniper on Jan 6, 2018 9:02 PM


 
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Sam Sellitto
(Login sell0682)
YF12

Nice informative video! NT

January 7 2018, 8:28 AM 

NT

 
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Skip in WV
(Login SkipinWV)
YF12

Pellet sizing

January 7 2018, 9:27 AM 

Good info. Thanks. Perhaps I need to get a pellet gauge to determine which size it likes best. At this point I'm not sure with the way I shoot all the extra effort is worth the time.

The reason I asked is my Steyr prefers the JSB Monster 13.4 pellets and every one I've measures is between 4.45 and 4.49. All from several different tins.


    
This message has been edited by SkipinWV on Jan 7, 2018 9:57 AM


 
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Tom Holland
(Login xbowsniper)
YF12

Re: Pellet sizing

January 7 2018, 10:13 AM 

Skip,
That's a huge difference, and sometimes when you use regular calipers, whether it is digital or not, it's tough to get an accurate reading on. I've found that 8.44 grain Air Arms or JSB'S will vary between 4.50-4.55.... in the same tin. A Pelletgage is the way to go. It helps with the consistency of the pellets, so you can know your pellets are uniform to each other, and greatly reduce the flyers.

 
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nced
(Login SpringerEd)
YF12

Before I started sizing my CPLs using a home made sizer I found a few "practices".........

January 7 2018, 3:41 PM 

that help with getting a relatively consistent pellet head measurement. While I'm not convinced that a digital or dial caliper will give a "precisely accurate" "metric second decimal point", however I have found that a proper sort procedure will be accurate enough for a consistent fit in the lead of the barrel, unlike pellets loaded directly from the tin or box. I'm of the opinion that as long as the pellet head is large enough to be "swaged a bit" when loading into the breech, "that silly little 1/100th of a millimeter" variation doesn't make much of a difference (if any) in the poi. The issue where a couple 100th of a mm makes a difference is when using loose fitting pellets where some are too small to be swaged to "leade size" when loading.

When I'm measuring pellet heads I follow these steps......
1. Start with a digital caliper that has an advertised resolution and accuracy of at least 0.01mm/0.0005.
VQtFc1sl.jpg
6pWARhZl.jpg
aDmVexdl.jpg

2. Using a test bar from my micrometer I check out the accuracy of the caliper when measuring.
This pic shows my other IGaging brand of caliper......
GP6G6Grl.jpg

3. After verifying the accuracy of the caliper, a lot of the verifying is developing a "consistent feeling" when closing the jaws over the pellet head. Here is how I judge the caliper pressure on the pellet head........
JkExcWJl.jpg
Keep in mind that pellet heads are often oval instead of round, often by .02mm or more (due to slightly mismatched die halves?). I also do several measurements of the pellet heads at the same point to verify the pressure used on the caliper jaws (measuring pellets by caliper is very tedious). The tediousness of measuring pellet heads did prompt me to create my own pellet head sizers which cuts the sorting time down to about 5 seconds for each pellet, during which the pellet head is swaged down and pellet skirt is "expanded/rounded" in a uniform fashion. I also mark the caliper jaws so the pellet head is always measured at the same point on the jaws........
xDKoJrpl.jpg

Here are 9 tins of JSB Exacts straight from the tins labelled 4.52mm after they were measured and sorted......
udeSRarl.jpg
Notice that most pellets from tins of Exacts labelled 4.52mm were 4.49-4.51mm.

As mentioned previously, while I'm not saying my pellet head measurements are exactly what I marked due to the caliper doing the "rounding off" at the "second metric decimal", I can verify that the various sorted sizes do fit the leade consistently within their "sorted groups" and are more accurate at the target.
8SZm6IEl.jpg
v6Ug0yHl.jpg











 
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Skip in WV
(Login SkipinWV)
YF12

Pellet gauge

January 7 2018, 12:21 PM 

Looks like one in my future. Thanks.

Ok. I ordered one. But, with the way I shake when shooting it may not help.


    
This message has been edited by SkipinWV on Jan 7, 2018 1:09 PM


 
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nced
(Login SpringerEd)
YF12

LOL.....I'm betting that sorting your "outta tin pellets" into groups.........

January 7 2018, 3:46 PM 

will help with consistency at the target unless the pellets chosen are Loose fitters. At least shooting "sorted lots" of pellets will minimize one variable.

 
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Skip in WV
(Login SkipinWV)
YF12

Extra effort

January 7 2018, 4:21 PM 

Probably won't make a difference. Just another puzzle to figure out.

 
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Dutch
(Login Dutch.22)
AR&P

How About A Scope Knob Video??nt

January 9 2018, 7:18 PM 

v

 
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Dutch
(Login Dutch.22)
AR&P

How About A Scope Knob Video??nt

January 9 2018, 7:28 PM 

v

 
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Dutch
(Login Dutch.22)
AR&P

How About A Scope Knob Video??nt

January 9 2018, 7:28 PM 

v

 
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Tom Holland
(Login xbowsniper)
YF12

Re: How About A Scope Knob Video??nt

January 9 2018, 7:46 PM 

Dutch,

I'm not much into tech stuff, I don't own Scopeknob, nor how it works. I occasionally use Chairgun, if I'm pressed for time, and even at that, it's just to get a ballpark starting point. In general, I don't use, nor depend on them, all my marks on my turret, I actually shoot. I found that the data doing it real time, much more accurate than a lot of programs out there. I own Ray Apelles program, and many people swear by it, but I haven't really tinkered with it enough in order to be useful to me at the moment. Maybe that I'm snowed in here in the Northeast, I might get to it.
You might want to ask this question on a new headline thread, I'm pretty sure there are MUCH more qualified individuals than me that can steer you to, or create an instructional video on it. I'd watch it as well!!!

 
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