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supercharged86 · Member

Just bought my first can of JSB .177 pellets, Diabolo Exacts. According to PyramydAir they weigh 8.4 grns. However, printed on the cover as well as on the JSB website, they have a different number listed, 0,547g. Just curious how the US retailers come up with a number of 8.4 grns? Is there a special conversion forumula? Thanks in advance. Steve

supercharged86 · Member

rsterne · Moderator

1 gram = 15.43 grains.... therefore 0.547g is 8.44 grains....

JSB round nose pellets nominal weights are:

.177 Exact RS 7.3 gr.
.177 Exact Express 7.8 gr.
.177 Exact 8.4 gr.
.177 Exact Heavy 10.2 gr.

.20 Exact .20 cal 13.5 gr.

.22 Exact Jumbo RS 13.4 gr.
.22 Exact Jumbp Express 14.3 gr.
.22 Exact Jumbo 15.8 gr.
.22 Exact Jumbo Heavy 18.1 gr.
.22 Exact Jumbo Monster 25.4 gr.

.25 Exact King 25.4 gr.

They have a huge selection of wadcutters and a few pointed pellets as well.... My experience is that the weight of individual batches varies about 0.1 gr. either way.... Wink

Bob

broommaster2000 · Moderator

One should, for reference, micro-weigh these.

Professional shooters weigh their pellets. When you're gonna shoot long range, it definately helps sorting them for weight and size.

packrat · Senior Member

I got my first Exact Jumbo Express pellets yesterday vis UPS..you can just look at those and tell that they are quality..quite different from the Crosmans I've been using !!Also got superdomes, hobbys and silver bears...nice how they all have the wieght printed in the tins Thumb Up!

supercharged86 · Member

Thanks guys, I hope the JSB's work out in my two rifles.

DeadEye · Member

rsterne · Moderator

When I weigh pellets to determine the lot weight, I count out 100 pellets and use a gram scale.... If you want to sort pellets to 0.1 grains, you are in for a LOT of work and unless you are a 10M target shooter, or shooting at over 50 yards, you will never see the difference.... Laughing

On an 8.4 grain pellet, 0.1 gr. is 1.2%.... at 700 fps, that is 8 fps, and that is assuming the pellets are exactly the same diameter and bore drag.... The difference in POI at 50 yards from that velocity difference with a JSB Exact pellet would be 0.066".... Even a 0.2 gr. difference in weight would only change the POI by 0.135".... less than the diameter of the pellet.... Rolling Eyes

High quality pellets (such as JSB) are often available sorted at the factory by diameter.... ie 4.50, 4.51, 4.52, and 4.53mm.... Bear in mind that the difference between 4.50 and 4.53 mm is just over 0.001".... and way less than 1% of the pellet diameter.... There can be a significant difference in not only the POI, but also the group size with just a 0.01 mm change in diameter.... I'd try all the different diameters available in the pellet of my choice instead of worrying about the weight tolerance from pellet to pellet.... Besides, what are you going to do?.... sight in for each different weight?.... Shocked

Bob

broommaster2000 · Moderator

Wasn't that's why we invented target dots, stripes, etc. And I simply ment sorting for match and for long range shooting. There are a lot of people who get reasonable groupings without sorting there pellets and wonder why it doesn't get tighter.

Sure, you'll be able to hit a can 9 out of 10 times, but for those ranges I'd go for a 10 out of 10. Mr. Green

Someone on the dutch forum has actually done this with JSB pellets or something. I'd post the results but dang it, I can't find it. Neutral