JSB Jumbo Monster Light .22 Caliber 20.83 Grain Pellets Test Review


Testers: Doug Wall, Stephen Archer

Caliber: 0.22

Test Date: June 28, 2024

Source of Supply: Supplied by Predator International

Condition: New

We Like

Consistent head sizes

Good Ballistic Coefficient


We Don't Like


Variable weights

Nothing else


  • Comparison to Makers Claims:
  • Most Common Head Diameter
  • Variation in Head Diameter
  • Most Common Weight
  • Variation in Weight
  • Most Common Length
  • Variation in Length
  • Dirtiness



JSB Jumbo Monster Light .22 Caliber 20.83 Grain pellets bridge the gap from the 18.13 Grain JSB Jumbo Heavy pellets to the 25.39 Grain Jumbo Monsters that are familiar to so many PCP air rifle shooters

This makes them useful for those with powerful .22 caliber PCP air rifles who are looking for that perfect balance of Muzzle Velocity and power. At 0.034, the Ballistic Coefficient is excellent for downrange performance. Plus the head sizes are very consistent. In HAM’s BC testing, they shot very well.

So why only a HAM Bronze Award? Well, they are quite expensive – largely due to being packed in small, 200-count tins. Also pellet-to-pellet weight consistency is rather less than we would like to see.

If you are OK with the price, these Monster Lights are likely to perform very well in a wide variety of PCP air rifles.


It has to be said that JSB Jumbo Monster Light .22 Caliber 20.83 Grain pellets are relatively expensive. At the time of writing this review, the “headline” price at Pyramyd – that is before the “pay for three get four” program – is 7.5 Cents each.

However this is partially due to the fact that they are sold in small, 200-count tins. The pellet count per tin does matter. For example, 18.13 Grain JSB Jumbo Heavy pellets have a headline price of 6.0 Cents each in 250-count tins at Pyramyd. That falls to 4.6 Cents each in 500-count tins.

Yes, the Monster Light price falls to 5.6 Cents each if you order four tins from Pyramyd. However HAM Awards are “value” awards that are based on a relationship between price and performance. So they take a hit from being packed in small tins.

JSB Exact Jumbo Monster Light .22 Cal, 20.83 Grains, Domed, 200ct 0.22

JSB Jumbo Monster Light Pellets Now Shipping



Price per Pellet7.50 cents
Most Common Weight20.93 Grains
Pellets at That Common Weight12%
Variation in Pellet Weight (Smallest to Largest)3.79%
Most Common Head Diameter5.56 mm
Pellets at That Common Diameter54%
Variation in Diameter (Smallest to Largest)0.18%
Most Common Length8.26 and 8.27 mm
Pellets at That Common Length16%
Variation in Length (Smallest to Largest)1.72%



The JSB Jumbo Monster Light .22 Caliber 20.83 Grain pellets tested by HAM had an average weight of 20.87 Grains. That’s less than 2% away from the claim and excellent performance, even though only 4% of the tested pellets actually weighed-in at precisely the 20.83 Grain specification.

JSB Jumbo Monster Light Pellets Now Shipping

JSB claims that there are 200 pellets in the tin. We counted 202 in the review tin.

The manufacturer makes no specific Ballistic Coefficient claims for these pellets. However independent testing to our standard HAM protocols results in a BC of 0.034. That’s a good result that’s in line with other heavy .22 caliber JSB pellets.



Manufacturing consistency is critically important for downrange accuracy. That’s why HAM Tester Doug Wall spends so much time weighing and measuring each individual pellet!

We need to be explicit that good manufacturing consistency does NOT guarantee that a particular barrel will “like” a certain pellet. However, it does mean that – if compatible with the barrel – the shot-to-shot accuracy on target will be better with consistently-manufactured pellets than those with less consistency.

A key component of airgun pellet manufacturing consistency is head diameter. Here the Jumbo Monster Light pellets gave excellent results!

54% of the tested pellets had a head size of 5.56mm. The remaining 46% were all 5.57mm. That means that the larger pellets had a head diameter of just about one third of one thousandth of an inch smaller than the others.

This is very good consistency, however the actual head diameters are well above the nominal 5.52 mm bore diameter for .22 caliber airguns.

JSB Jumbo Monster Light .22 Caliber 20.83 Grain Pellets Test Review

As usual, weight was somewhat more variable. The most common weight per pellet was 20.93 Grains, with 12% of the pellets tested having that weight.

The variation between the lightest and heaviest Jumbo Monster Light pellets tested was 3.79%. This is rather worse than average, based on HAM’s highly standardized, precise test protocol.

As always, all weights are measured using on Hard Air Magazine’s incredibly-precise, laboratory-grade milligram balance. This is so sensitive that it even registers a person’s breath! That’s where HAM tester Doug Wall’s many years of research laboratory experience is vital for achieving such accurate measurements…

Normally in HAM testing, we find that pellet lengths are the least consistent. However, the JSB Jumbo Monster Light .22 Caliber 20.83 Grain pellets showed good length consistency. As many as 32% of the tested pellets had a length of 8.26 or 8.27 mm.

The difference between the shortest and longest pellets tested by HAM was 1.72%. Again, this was a better than average result.

Four pellets in the tin of Jumbo Monster Lights showed the effects of slight skirt damage, probably caused in transit.



The JSB Jumbo Monster Light pellets tested by HAM had a total of 0.260 Grains of dirt per 100 pellets. Again, this is a good (low) figure.

Some residual dirt and dust is an inevitable part of manufacturing any lead pellets and a certain amount of it inevitably finds its way into the tin. The photograph below shows the amount of this “junk” which resulted from carefully washing these pellets.

JSB Jumbo Monster Light Pellets Now Shipping



During HAM Ballistic Coefficient testing, JSB Jumbo Monster Light .22 Caliber 20.83 Grain pellets achieved a BC of 0.034.

As the Chairgun graph below shows, Muzzle Energy holds-up to 50% even out at around around 83 Yards downrange (50% KE).

Flatter shooting and increased hitting power downrange are the benefits of the strong Ballistic Coefficient!

JSB Jumbo Monster Light .22 Caliber 20.83 Grain Pellets



Penetration into our standard ballistic soap block was a long 52 mm using the standard Beeman 1074 test air rifle. The diameter of the entry hole was 8.0 mm.

The photograph below shows the fired pellet after extraction from the soap – right. As we can see compared to an unfired pellet, the head diameter increased from 5.56 mm to 5.61 mm. At the same time, the length shortened from 8.28 mm before firing to 8.21 mm.



Jumbo Monster Light pellets are readily available online from from Airguns of Arizona, Airgun Depot, Pyramyd Air and more.

They are supplied in the new JSB screw top tin with a foam disk under the lid to minimize damage in transit.



JSB Jumbo Monster Light .22 Caliber 20.83 Grain Pellets Test Review

JSB Jumbo Monster Light .22 Caliber 20.83 Grain Pellets Test ReviewFor background details on HAM’s Pellet Test Review methodology, check out this link.

Chairgun is a product of Hawke Sports Optics LLC and is used with permission. Check out http://www.hawkeoptics.com

JSB Exact Jumbo Monster Light .22 Cal, 20.83 Grains, Domed, 200ct 0.22

Understanding HAM Pellet Awards

HAM Pellet Awards come from the most rigorous, professional and comprehensive pellet testing by any independent publication. They are the result of much precise measurement and analysis using high precision measuring devices and highly-experienced testers.

Note that accuracy is a product of the complete “system” of airgun, scope, atmospheric conditions and shooter ability – not the pellet alone.

This means that no pellet test review can predict the accuracy of a particular pellet with YOUR individual air rifle. That’s why we do not measure accuracy in these pellet tests.

What HAM Pellet Awards do recognize is manufacturing consistency. Inconsistent pellets definitely will be inaccurate, consistent pellets are much more likely to be accurate.

HAM Awards also recognize value. There’s considerable variation in the price of airgun pellets. This means that an 8 cent pellet needs to score higher than a 2 cent pellet to achieve an award.

For full details of the HAM Pellet Award scoring methodology, please check out our Pellet Testing page.

For a full listing of HAM-tested Ballistic Coefficients, please see our Ballistic Coefficients page.

This entire article including scoring, data etc is Copyright Hard Air Magazine and may NOT in part or in whole be reproduced in any electronic or printed medium without prior permission from the publisher.