Author Topic: Pellet head sizes - sharing my spreadsheet (Read 7639 times))

nervoustrigger · « **on:** February 07, 2013, 12:31:59 AM »

Updated Aug 14, 2013: .22 caliber updates:

CPHP
H&N FTT 5.53mm
JSB 13.4gr
JSB 15.9gr
Predator Polymag
RWS SHP

These new entries are highlighted in yellow so they're easy to spot.

As with their .177 counterparts, it looks like JSB and H&N have the more consistent head sizes in the group.

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Updated Aug 12, 2013: new copy attached with several pellets added, mostly in .177 caliber. For new entries, now including the standard deviation which, along with the extreme spread, gives a good sense of how consistent the pellets are from a given tin.

As before, standouts are highlighted green for good and red for bad.

If you are interested in compiling your own data, there's a calculator below the main table where you can enter in up to 20 measurements and it will summarize the average, extreme spread, etc. which you can then add to the table.

Also has a simple fpe calculator and a couple of additional sheets, one for plotting a PCP shot string and another with my little table of Sun Optics adjustable scope rings.

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Old post:

Good evening guys.

I just wanted to share a copy of my pellet log. Some high points:

1. head sizes: typical, min, and max head sizes
2. calibers represented: mostly 22 cal and a few 177 cal
3. rifles tested in: accuracy comments for each one...I only have 4 rifles but I know some of you guys have the same models
4. vendor info: vendor and purchase date to give you a sense of how fresh the data is, and thus whether you can reasonably expect to get something similar if you were to buy a tin today.

If you have a rifle that is picky about head size, I am hoping you may find it useful. Comments and criticism welcome.

thekid · « **Reply #1 on:** February 07, 2013, 01:05:16 AM »

Thanks for taking the time to contribute this info.
Hopefully it helps some one out, when looking for a pellet for a certain gun.
Very cool of you.

limbwalker · « **Reply #2 on:** February 07, 2013, 09:45:32 AM »

Thanks!

Sinner · « **Reply #3 on:** February 07, 2013, 11:00:02 AM »

Downloaded! Thank you very much for this awesome, helpful info. It's nice to have resources like this on hand for quick reference.

drewciferpike · « **Reply #4 on:** February 07, 2013, 04:00:01 PM »

NICE! This information is great.

Did you save yards-to-target and group size information? I'm just wondering what "crazy accurate" is, haha.

I'll be doing some testing with my XS25, once I get access to a chrony, so I'll use this same spreadsheet layout.

JMJ in NC · « **Reply #5 on:** February 07, 2013, 04:20:04 PM »

Good info.

It would be interesting to see the bore size of each of the guns as compared to the head size of the pellets. For instance, my Crosman 1377 carbine has a slightly larger barrel than my Walther Force 1000 break-barrel. My Crosman loves JSB Exacts, Hevies, and Monsters. The Walther prefers Beeman Crow Magnums.

The bore size can be measured with gauge pins (carefully) or by pushing a lead pellet through the bore and measuring the smallest diameter with calipers.

Did you measure the pellets with a caliper or a micrometer?

JMJ

BenjiHunter · « **Reply #6 on:** February 07, 2013, 04:42:30 PM »

Great info!!

nervoustrigger · « **Reply #7 on:** February 07, 2013, 04:47:52 PM »

I have the muzzle diameters for my rifles so I'll see about analyzing that tonight. Thanks for the suggestion. As for measurement method, please see the notes below the table.

JMJ in NC · « **Reply #8 on:** February 07, 2013, 05:01:17 PM »

Quote from: nervoustrigger on February 07, 2013, 04:47:52 PM

As for measurement method, please see the notes below the table.

Sorry - missed that. Thanks - JMJ

nervoustrigger · « **Reply #9 on:** February 07, 2013, 08:11:46 PM »

Quote from: drewciferpike on February 07, 2013, 04:00:01 PM

I'm just wondering what "crazy accurate" is, haha.

Yeah, not exactly an SI unit of measure, is it?

Crazy accurate I consider to be 3/8" CTC 5-shot group at 25 yards with the B51 and Predator Polymags. And no fliers that I can attribute to anything but me.

And I'm no marksman, I don't care what it says over there under my handle.

nervoustrigger · « **Reply #10 on:** February 07, 2013, 08:20:13 PM »

And a 3/4" 7-shot group with the B51 and JSB 15.9 at 45 yards. To me, that's crazy because I could never dream of such while shooting springers and gas rams...even once on a good day. Those who can have my utmost admiration and respect. Oh, and jealousy. This I can shoot any time, in fact this one was after 4 hours of hard yard work when my muscles were tired and twitchy.

drewciferpike · « **Reply #11 on:** February 07, 2013, 08:30:17 PM »

That's awesome. I'll be honest: I want to learn to shoot my springer well, but the siren-call of PCPs is steadily growing stronger...

nervoustrigger · « **Reply #12 on:** February 07, 2013, 11:57:05 PM »

Okay, here's a new copy that begins to explore the relationship between the pellet head size and muzzle diameter.

Firstly, note I'm distinguishing the muzzle here because I don't have the tools to reliably measure the bore diameter. My assumption is if there is a difference between them, the muzzle will be the smaller of the two. However, I tend to think there is little to no choke on any of my three (3) .22cal barrels based on the muzzles measuring 0.2155" to 0.2160". The Beeman RS2 is the only one that I can noninvasively access the breech and it measures the same on each end.

I was thinking the B51 was choked based on its stellar accuracy but I guess not.

My only .177 cal, the lowly Daisy 880, measures 0.178 or maybe even 0.179 (hard to tell) so that may explain why I've had such a hard time finding a pellet it likes. Until seeing this, I figured it was equal doses of several imperfections. After all, what can I expect from a $40 air rifle? But now I'm tempted to put some choke on it and see what happens. Anybody have some DIY pointers? I have a hammer and a mean streak

Anyway, on with the analysis...

So what's new?

Have a look at the red circled areas in the screenshot attached. Here's what's been added:

1. spread calculation - Difference in max and min head diameters in the tin. Those with a spread of >0.003" (0.076mm) or greater are highlighted red.
2. pellet to rifle correlation - this is a group of 3 new columns titled:
a. shoots well in / shoots poorly in [this rifle...]
b. whose muzzle is sized
c. for a difference of (with respect to the pellet)

How do I read it?

Since there are many pellets that are sort of ho-hum, mediocre, or inconclusive, what I did was focus on those at the extremes. The very good and the very bad.

The good combinations are highlighted bright green. The poor combinations are highlighted bright pink.

What does it mean?

Well, I humbly submit what I think it says. Snug-fitting pellets do not ensure good accuracy but undersized pellets pretty well guarantee poor accuracy. Kinda like the old saying about horse racing, the win doesn't always go to the swift. But that's the way to bet.

Lastly, the hall of shame

Check out the spread on the Gamo Match wadcutters. 9 thou. or 0.23mm! These were a gift from my sister-in-law. How could she know? How could anyone know they could be that bad? And yes, they are absolutely abysmal at grouping. Flyers the likes of which I have never seen before.

Hey, it's the thought that counts.

Briar Patch · « **Reply #13 on:** February 08, 2013, 08:58:46 AM »

Excellent! Significant amount of time invested there - I appreciate your efforts. FPE calculator at the bottom is a very nice touch!

It's a nice bonus that your work provides a great template for anyone else who wants to assemble the information for the guns and ammo they have.

Very well done Sir!

One Shot One Beer · « **Reply #14 on:** February 08, 2013, 03:04:39 PM »

Really appreciate this work! I think (and hope) that this and a few other recent pellet to gun comparison threads are going to get a larger ball rolling. Maybe there's a way to generate a top 5 pellet listing for various rifles, even if the data is coming from different sources. It's a whole extra layer of serious to wrap around this awesome hobby.

nervoustrigger · « **Reply #15 on:** February 08, 2013, 06:03:39 PM »

Thanks for the kind words, Briar. That's been the highlight of my day so far!

nervoustrigger · « **Reply #16 on:** August 13, 2013, 02:31:49 AM »

Hey guys, in case anyone is interested, I made a few updates to the spreadsheet and posted a new copy in the first post.

Take care,
Jason

BenjiHunter · « **Reply #17 on:** August 13, 2013, 05:29:03 AM »

Great job! Thanks for sharing.

daemon2525 · « **Reply #18 on:** August 13, 2013, 10:21:49 AM »

OK, Maybe it's just me. But through heresay and actual testing, I have an Idea which pellets are most accurate.

It seems that the ones that I would guess to be the most accurate are all either the correct size or larger.
The undersize ones are the least accurate.

In .22 I have seen that CPHP and JWS-Jumbo shoot well for me and RWS superdome does not.

My rifle like the larger pellet?

Chaffyn · « **Reply #19 on:** August 13, 2013, 12:45:53 PM »

Super duper wild and WOW, Jason. Many thanks!

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Pellet head sizes - sharing my spreadsheet

Author Topic: Pellet head sizes - sharing my spreadsheet (Read 7639 times))

limbwalker

One Shot One Beer