Weighing pellets for benchrest.

[Bardot]

Anybody taking the trouble to weight their benchrest pellets? If so to what degree of accuracy due you batch them and what level of difference do you think in makes.?

 

[Bowland Blades]

In true bench test accuracy changes like this should be tested and proved , still most of it is still likely not to matter - but your brain should never really be in on that fact!

 

[Mick_Green]

This is why you weight them, if I'm competition shooting, I only used weighed and sorted pellets. Can't blame the rifle if i miss.

I sorted some JSB Exact Diablo 8.44 grain pellets the other day the ranged from 8.36 to 8.68

You got to love AI.

At 30 yards with a UK sub-12 ft-lb air rifle, the difference in point of impact between an 8.44 grain and an 8.55 grain pellet is small but measurable—typically around 3 to 5 millimetres lower for the heavier pellet, assuming all other factors (shape, head size, wind, etc.) are identical.
Breakdown of the Impact Shift
• Velocity drop: The 8.55 grain pellet will exit the barrel slightly slower than the 8.44 grain one—roughly 5–10 fps difference depending on your rifle’s efficiency.
• Time of flight: The slower pellet spends more time in the air, allowing gravity to act longer, resulting in a slightly lower impact.
• Vertical drop: At 30 yards, this translates to a vertical shift of approximately 0.1 to 0.2 inches (≈2.5 to 5 mm).

 

[Bardot]

This is why you weight them, if I'm competition shooting, I only used weighed and sorted pellets. Can't blame the rifle if i miss.

I sorted some JSB Exact Diablo 8.44 grain pellets the other day the ranged from 8.36 to 8.68

You got to love AI.

At 30 yards with a UK sub-12 ft-lb air rifle, the difference in point of impact between an 8.44 grain and an 8.55 grain pellet is small but measurable—typically around 3 to 5 millimetres lower for the heavier pellet, assuming all other factors (shape, head size, wind, etc.) are identical.
Breakdown of the Impact Shift
• Velocity drop: The 8.55 grain pellet will exit the barrel slightly slower than the 8.44 grain one—roughly 5–10 fps difference depending on your rifle’s efficiency.
• Time of flight: The slower pellet spends more time in the air, allowing gravity to act longer, resulting in a slightly lower impact.
• Vertical drop: At 30 yards, this translates to a vertical shift of approximately 0.1 to 0.2 inches (≈2.5 to 5 mm).

I fed some realistic values into google and the AI Bot spat this out.


For a pellet with an initial muzzle velocity of 750 feet per second, an 0.1 grain weight difference from the average 8.4-grain pellet can cause an impact shift of approximately 0.38 millimeters (0.015 inches) low at 25 meters. This calculation assumes the rifle's power output remains constant for both pellet weights.

 

[terry1001]

If I were shooting where consistency was essential I would certainly weigh the pellets. Even those made by top manufacturers can exhibit quite a lot of variation in weight. It akso gives you the chance to visually inspect each pellet so you can discard any which have visible defects. The variation in weight can be down to tiny differences in thickness but a heavier pellet may have a bit of swarf inside the tail which would result in a slight imbalance possibly causing the trajectory to be affected. Although skirt damage often seems to be corrected on firing I won't use a pellet showing any damage for anything other than the most casual plinking.

 

[Frog]

Anybody taking the trouble to weight their benchrest pellets? If so to what degree of accuracy due you batch them and what level of difference do you think in makes.?

Yes I weigh sometimes and group pellets into 0.2 gr groups - e.g. 8.1-8.3, 8.31-8.5gr , 8.51 gr - 8.7 grain.

This can stop you shooting an out of the tin 8.1gr pellet followed by an 8.7 gr one - and it does make a difference when trying to obliterate a 2mm target at 25m.

 

[GridNorth]

I weighed 4 x tins of JSB Heavies but gave up as it seemed to be a waste of time. Every pellet was within a couple gr. Perhaps I just dropped on a good batch but I experienced a similar consistency with 2 or 3 tins of QYS. There is of course the possibility that my scales are faulty.

 

[P8X]

I personally don’t think it matters
Any errors when I shoot are mine not the kit
This is as card I shot the other day where I slipped on the top left target
Pellets straight out of the tin
If I hadn’t slipped on that last shot it would have been rather a good card

 

[ricardolamos]

I agree,shots that go awry I can normally attribute to my lack of concentration/movement rather than differences in the pellets.

Clearly if the pellet is damaged and/or there is substantial inter-pellet weight difference this is best avoided but if you take this out of the equation human error is I think the biggest factor.

 

[51Rider]

I weighed 4 x tins of JSB Heavies but gave up as it seemed to be a waste of time. Every pellet was within a couple gr. Perhaps I just dropped on a good batch but I experienced a similar consistency with 2 or 3 tins of QYS. There is of course the possibility that my scales are faulty.

Wow! You must be lucky with that batch.
I’ve weighed 3 tins of JSB heavies from the two sleeves of the die that my rifle seems to like and the weights vary from 10.30 to 10.52 grains. I’ve also filled a QYS tin with pellets that have damaged skirts and I do mean filled.
I was able to shoot a 10 shot string over a chronograph the other day with these sorted pellets and had a standard deviation of just 1.3 fps after we deleted an oddity that skewed the readings by 22fps. To me, it is very much worth the time taken to weigh and sort them although I might need to be a little more vigilant given the aforementioned flyer

 

[Turkish]

In my opinion an absolute waste of time. All pics from this mornings range at Yarners Durham. This was 10 shots at 25 yards - all through the same hole. Then a decent card shot again at 25 yds. Pellets straight from the tin
And this was the culprit

 

[OolonCaluphid]

I recall weighing batches of pellets in my dad's lab, on a calibrated scientific scale accurate to a milligram! More to judge the manufacturing consistency than to try and batch them as he wasn't a target shooter.

If I was shooting ten bulls again I think it would be an easy area to exclude outliers.

 

[Simona]

This is why you weight them, if I'm competition shooting, I only used weighed and sorted pellets. Can't blame the rifle if i miss.

I sorted some JSB Exact Diablo 8.44 grain pellets the other day the ranged from 8.36 to 8.68

You got to love AI.

At 30 yards with a UK sub-12 ft-lb air rifle, the difference in point of impact between an 8.44 grain and an 8.55 grain pellet is small but measurable—typically around 3 to 5 millimetres lower for the heavier pellet, assuming all other factors (shape, head size, wind, etc.) are identical.
Breakdown of the Impact Shift
• Velocity drop: The 8.55 grain pellet will exit the barrel slightly slower than the 8.44 grain one—roughly 5–10 fps difference depending on your rifle’s efficiency.
• Time of flight: The slower pellet spends more time in the air, allowing gravity to act longer, resulting in a slightly lower impact.
• Vertical drop: At 30 yards, this translates to a vertical shift of approximately 0.1 to 0.2 inches (≈2.5 to 5 mm).

I don't go along with some of these assumptions. With JSBs the lighter pellets tend to generate lower power than heavier ones, narrowing the velocity and drop difference. The heavier ones will likely have a better BC too leading to further convergence of drop.

The really tricky thing to assess is barrel position at pellet exit. If the faster and slower pellets are exiting at a position each side of a node that compensates for their velocity differences then you could have a really accurate gun, regardless of velocity differences.

I used to shoot a lot indoors at 50 yards with my Walther LG300, that I still own. The most accurate batch of JSBs I ever had, in 2011, looked awful and were among the very worst that I'd ever had in terms of weight spread. They were super over the chrono- the velocity was so consistent, it was the power that varied. They went through the same hole at 50 yards. I had 20 tins of them so I got to know them pretty well.

There's no clear proxy for pellet accuracy. Aside from discarding damaged ones, accuracy is something that has to be tested for.

 

[Simona]

I don't ever weigh pellets anymore but I do test different batches. But I do shoot FT not BR. It's difficult to know how much inaccuracy I personally introduce but I am looking for very good accuracy, at 30 yards I looking to put 5 through a 6 or 7mm hole when I'm shooting nicely.

 

[Frog]

I don't ever weigh pellets anymore but I do test different batches. But I do shoot FT not BR. It's difficult to know how much inaccuracy I personally introduce but I am looking for very good accuracy, at 30 yards I looking to put 5 through a 6 or 7mm hole when I'm shooting nicely.

I agree for FT or HFT I don't bother either but the targets are around 3MOA vs. 0.5MOA for BR....