JSB Jumbo Express 14.35 Grain .22 Caliber Pellet Test Review


Testers: Doug Wall, Stephen Archer

Caliber: .22

Test Date: Oct 12, 2021

Source of Supply: Supplied by Predator International

Condition: New

We Like

Consistent head diameters
Very clean
Good price

We Don't Like

Poor weight consistency in this tin
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



These JSB Jumbo Express 14.35 grain pellets so nearly earned a HAM Gold Award! Just a fraction more consistency in pellet weight or length would have made all the difference…

Overall, these are great mid-weight .22 caliber pellets with an excellent reputation from the Czech manufacturer. The price is very fair, the pellets are clean and packaging good with screw-top tin and foam slip.

HAM has long used these pellets for general testing purposes and we’ve always been happy with their performance.

If you’re looking for domed pellets for a low to medium power .22 caliber air rifle, these definitely fit the bill. They’re likely to be somewhat too light for the latest generation of super-powerful PCPs. However, that’s why JSB manufactures heavier pellets too!


We tested these pellets in a 250-count tin. At 4.4 Cents each, JSB Jumbo Express 14.35 grain pellets are very well priced for good quality pellets having an excellent reputation.

However they are also available in 500-count tins. In this case the price per pellet drops to 4.2 Cents each. That’s a worthwhile saving and extremely close to the Median price for lead pellets in this caliber. Buy the big tins!

Owners of the latest generation of super-powerful .22 caliber air rifles will know that the weight of these domed pellets is too low for their guns. These 14.35-Grainers are ideally suited for use in spring/piston air rifles, however, as this weight will not overpower most springers’ powerplants.

They are also likely to work well with PCPs having a maximum power of up to about 30 Ft/Lbs in .22 caliber, as the Muzzle Velocity will not be too high for best accuracy.

JSB Jumbo Express 14.35 Grain .22 Caliber Pellet Test Review

JSB Diabolo Exact Jumbo Express .22 Cal, 14.3 Grains, Domed, 500ct 0.22



Price per Pellet4.39 cents
Most Common Weight14.27 Grains
Pellets at That Common Weight10%
Variation in Pellet Weight (Smallest to Largest)3.82%
Most Common Head Diameter5.53 mm
Pellets at That Common Diameter72%
Variation in Diameter (Smallest to Largest)0.36%
Most Common Length6.83 mm
Pellets at That Common Length28%
Variation in Length (Smallest to Largest)1.47%



The manufacturer makes a small number of claims for the JSB Jumbo Express 14.35 grain pellets.

One is that there is 250 pellets in the tin. Check! The second is that the pellet weight is 14.35 Grains. Although the weight of the sample pellets tested in this HAM review was somewhat ragged, the average was EXACTLY 14.35 Grains. Check again!

JSB realistically claims that these pellets will give a higher FPS than the regular 18.13 Grain Jumbo Heavies. They also claim that they’re not too light to be affected by wind. HAM can’t test that in a structured manner. However the relatively high Ballistic Coefficient of 0.025 that HAM has measured for this pellet gives support to the claim.



Firstly we need to report that all 250 pellets in the tin tested by HAM were in perfect condition. None showed any signs of malformation in manufacturing or damage in transit.

The JSB Jumbo Express 14.35 grain pellets tested by HAM displayed well above average consistency of head diameter. In fact, no less than 72% of the pellets tested had the same head diameter of 5.53mm.

This is a good result and it’s worth noting that the “outliers” varied by only 0.01 mm diameter from the average – that’s a difference of just 4 Thou or less!

JSB Jumbo Express 14.35 Grain .22 Caliber

Unfortunately the consistency of weight among the JSB Jumbo Express 14.35 grain pellets tested by HAM was rather less good.

As always, all pellets were weighed using HAM’s incredibly-precise, laboratory-grade, milligram balance. This gives precise, accurate and consistent measurements.

The most common weight of the tested pellets was 14.27 Grains. Ten percent of the tested pellets had this weight. The range of weights varied between a minimum of 14.12 Grains and the maximum 14.66 Grains. Interestingly, only one pellet actually weighed the specified 14.35 Grains.

This result was less good than the HAM Team was expecting. However – as reported above – the average weight of the tested pellets was exactly 14.35 Grains. It’s unusual for the average weight to exactly match the specified weight, so this was good.

JSB Jumbo Express 14.35 Grain .22 Caliber

Length measurements showed much better consistency again. Well, all except for one pesky outlier, as you can see from the graph below. The most common length was 6.83 mm. 28% of the tested pellets had this length. This is good.

JSB Jumbo Express 14.35 Grain .22 Caliber

Without that one long exception, the length consistency score for these JSB Jumbo Express 14.35 grain pellets would have jumped from 60% to 90% in the HAM scoring system. That would have resulted in a Gold Award-winning total score.

Sorry JSB. We have to be firm but fair with our reviews!

Finally, it’s worth noticing that the Standard Deviation recorded when using our standard Beeman 1074 test rifle was just 3.65 FPS across 10 shots. This is a very low figure and demonstrates the strong consistency attainable with these pellets in practical use.



In any pellet-manufacturing process, a certain amount of dirt, dust and junk inevitably finds its way into the tin. However, the JSB Jumbo Express 14.35 grain pellets tested by HAM were very clean.

The photograph below shows the results of carefully washing the pellets. There’s very little residue there at all and what there is is mainly dust, rather than the lead shavings we often see. In fact, it’s just 3.086 Grains of dirt for the entire tin of 250 pellets. Very good!


In HAM’s standardized, comparable pellet Ballistic Coefficient testing, we found that.22 caliber JSB Jumbo Express 14.35 grain pellets have a BC of 0.025. This is a good value for a domed pellet of this weight. The result is seen in the downrange performance that’s calculated using the Chairgun software package.

JSB Jumbo Express 14.35 Grain .22 Caliber Pellet Test Review

Using our standard Beeman 1074 air rifle, Jumbo Express pellets provide an effectively “flat” trajectory from around 8 Yards out to 35 Yards. Combined with the energy retention data calculated by Chairgun, this would be the best range for hunting with an average breakbarrel of this type.

In fact, Chairgun shows that 79.1% of the Muzzle Energy is retained at 25 Yards downrange. However this falls to about 62.8% out at 50 Yards.



JSB Jumbo Express 14.35 grain pellets are not designed specifically for hunting. They’re general purpose pellets. However they could provide effective on the right quarry – small game at short-to medium ranges.

Penetration into the HAM standard soap block was 47mm, which is typical for domed lead pellets of around this weight. The wound channel entry hole in the soap block was 8mm diameter – again typical for pellets of this type and weight.

JSB Jumbo Express 14.35 Grain .22 Caliber Pellet Test Review

This pellet shrank on impact from 6.86 mm long to 6.66 mm – a slight reduction of about 3%. The diameter increased from 5.53 mm to about 5.61 mm – irregular.



JSB Jumbo Express 14.35 grain pellets are widely available online from all of the usual suspects – Pyramyd Air, Airgun Depot, Airguns of Arizona and others.

The screw-top tins now being used by JSB are a big improvement on the old friction-fit (push on) lids. They are much less likely to result in unexpected accidents when opening. How do we know? You can guess…

The foam pad under the cap also protects the pellets from shipping damage.


JSB Jumbo Express 14.35 Grain .22 Caliber Pellet Test Review

JSB Jumbo Express 14.35 Grain .22 Caliber Pellet Test Review

For 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 Diabolo Exact Jumbo Express .22 Cal, 14.3 Grains, Domed, 500ct 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.