Pellet testing

Well just sorted through the first ever tin of cometa exact jumbo. .22, 1.030grams(15.90 grains)
Pretty happy with first tin.
3 shot.
4 rejected on skirt damage.
4@1.06grams
19@1.05grams
15@1.01grams
So that leaves 200 approx, either .01gram above or below stated weight.
Roughly 60 odd each in 1.02/1.03 grams
80ish in 1.04 grams.
Thats probly the most even weight distribution around the pellet weight I've had.
Be interesting to see next tin and head size.
Tidy well cast pellets as well.



Edited by kruzaroad - 07 Apr 2024 at 5:37am

Well I'm totally impressed.
Those are the 2 most constant weight and head size I've ever seen in tins.
Working off 1.03grms as stated pellet weight.
Approx 100 of 500 fell into the 1.01grm and 1.05/1.06grm weight, head size still unsorted.
Of the the 400 approx left,they all fell into 1.02-1.04grm.
Of that 40 odd fell into the 5.51 and 5.54mm head size.
Rest were 5.52mm and 5.53mm. The later having considerably more.
Clean tins half a dozen damaged.
If the gun likes these I'll be stocking up on this batch number if I can.

I'll get another 5 tins if he has the same run number. Waiting to hear.
I'd be quite happy to have a bigger stash of sorted hunting pellets.
400/500 be nice.

Weighed 1000,4 rejected for skirt damage.
As scales only do to .00 allowing .005 either side of weight.
95% approx fell into the 1.02,1.03,1.04 grms.
1.04 definitely having more than 1.03grms but not by much. 1.02grams less than that but all close, sort of 385,290,225
Of the 5% left 8 were 1.06grams
40% 1.01gram and 60% 1.05grams.

U sure have been busy!
I hope those little yellow plastic dividers are glued down to the bottom of that black container!

Maybe I should be looking at skirts as previous asked.
Found an artical while looking for head sizer.
Quote:
The pellet head need only lightly touch the lands, so that the pellet doesn’t tip back and forth on the way down the bore, but the pellet’s skirt must cut into the rifling to effect an air seal.

In springers, the skirt has a very important second function, as James has pointed out. It interacts with the chamfer at the breech end of the barrel. Together with the pellet's weight, this determines the point in the piston’s travel, at which the pellet begins to move. If the skirt is too small, the pellet takes off too soon; power is lost and there is a minor “slam fire” effect on the piston. If the skirt is too big, the pellet will linger too long and the piston will bounce, again wasting velocity and making more felt recoil.

There is a lot of variety out there both in pellet skirt size (I’ve measured anything from .180” on Crosman ammo to almost .190” on some traditional RWS designs), and the breech chamfer detail (many guns today have a short, sharp-edged angled cut, some have a more carefully designed longer taper, some are in between).

IMHO experimenting with different ammo to match up skirt size vs. breech fit, is a really important part of shooting springers. It can have a huge effect on accuracy, consistent velocity, and firing behavior. It’s long been curious to me that pellet weight and head size seem to get the lion’s share of discussion, while this aspect is rather ignored.