30 Cal JSB Weighed and sorted ”Accuracy Test” today

[DLFant]

I thought I would share a comparison test I done today . I usually do all my practice with unsorted unweighed pellets. However I do sort and weigh if I am in a contest. I do a bit of centerfire reloading and have a very good set of digital electronic scales. I also have a head size gauge. Today I sorted by weight 5 tins of JSB 30 cal 44 grainers. They varied from 44.2 to 45.6 however out of all of them there was only 3 of the lightest (44.2) and 2 of the heavest (45.6). Most fell in between 44.7 and 45. We had very light wind today. It was a good time for a test. I have tried this several times with simular results using 22 cal 16,18 grain and 30 cal 44 grain JSB's .
Here is the test:
I took the 3 lightest (44.2) and the 2 the heavest (45.6) which had a head size 2 sizes larger than the light ones and shot a 5 shot group at 75 yards.
Here is the result Note:
I picked a blank spot on the target I was practicing on, the yellow dot is not part of the group. The group was actually smaller but the last light one (44.2) fell lower than the other 4. 


I will still sort and weigh because of the thought of it but its probably not really necessary espically with the heavier pellets. Hope this is helpful.

 

[Bwalton]

I shoot out the tin, never had the patience to weigh pellets.I think that is it gives peace of mind and takes out a variable do it. that wa y it will not be at the back of your mind. I think that if I was to compete then I would weigh the pellets.

 

[Astroman]

I did a sort by weight on a tin of 44.75 JSBs as well and pretty much see a similar distribution that DL described. However I also ran each pellet through a pellet gage and despite the weight spread, I found that every single pellet in this tin came in at 7.64 mm -- amazing consistency in head size!



I plan to shoot a few 75 yard groups this weekend early in the morning before the winds come up to see if group size is relatively insensitive to weight variation as DL found. Will report back what I learn. I also took the liberty of "reworking" some of the heavier pellets down to 44.8 gr by removing some material from inside the skirt -- to see if they perform the same as non-reworked pellets of the same weight.

 

[Bruce]

I always shot out of the tin. The only thing I do is look for damaged skirts. Good enough for targets and back yard pest.

 

[linsfreak]

wow! interesting, looks like something I would do.

 

[LDD]

It has always been my opinion that weight sorting is only beneficial in the .177 cal or in light .22 cal, and that happens to be the caliber that is too small and too cheap for me to worry about doing it to. At 45gr a 1gr variation only represents 1/45th of its weight, whereas 1/45th of a 7.8gr .177 is .173gr. The lighter the pellet the faster weight variations add up as a percentage of the overall weight of the projectile. Therefore a 7.8gr .177 that varies by .5gr has a variance of 1/16 of it's total weight. The 45gr pellet would have to vary by almost 3gr to be that bad. It is my opinion that variations in the head size play a larger part in accuracy issues than do small variations in weight.

 

[Bwalton]

The ES will have more of an effect then pellet weight from a tin, Head size is a little more important then the weight variance in .30cal, As head variance can cause spiraling of a pellet.