This is gonna be a very unusual post, in some ways it is still about technology even if it is not about the usual IT stuff I write of.
I have a Weihrauch HW 77 K spring air rifle I mostly use to shoot in my backyard or terrace.
When it comes to air guns I always have troubles finding proper reviews and comparisons online, so I figure it might be worth sharing my findings here.

weihrauch-hw77k

I usually shoot at paper targets at 10 meters or at beer bottles and cans at 50+ meters.
While this isn't a competition C10 air gun I find paper targets and hand held shooting at 10 meters the best way of improving my abilities and shooting campabilities; another thing I like about it is the ability to shoot in my terrace or garage even if the weather conditions are bad.
I rounded up a few pellets I had (flat head for 10 meters paper targets and domed for long range shooting) and chronographed them:

|:-------------------------:|:------:|:----------------:|:-------:|:---------:|:-----:|  
| PELLET                    | TYPE   | CALIBER          | WEIGHT  | SPEED     | JOULE |  
|:-------------------------:|:------:|:----------------:|:-------:|:---------:|:-----:|  
| JSB EXACT EXPRESS DIABOLO | domed  | 4.5 mm / .177 in | 0.510 g | 181.2 m/s | 8.375 |  
| JSB EXACT DIABOLO         | domed  | 4.5 mm / .177 in | 0.547 g | 171.7 m/s | 8.114 |  
| JSB TARGET                | flat    | 4.5 mm / .177 in | 0.520 g | 172.2 m/s | 7.715 |  
| RWS CLUB SPORT LINE       | flat    | 4.5 mm / .177 in | 0.450 g | 183.8 m/s | 7.606 |  
| RWS MEISTERKUGELN         | flat    | 4.5 mm / .177 in | 0.450 g | 193.2 m/s | 8.398 |  
| RWS SUPER-H-POINT         | hollow | 4.5 mm / .177 in | 0.450 g | 177.4 m/s | 7.080 |  
| JSB MATCH LIGHT WEIGHT    | flat    | 4.5 mm / .177 in | 0.500 g | 180.2 m/s | 8.123 |  
| JSB MATCH S100            | flat    | 4.5 mm / .177 in | 0.535 g | 172.3 m/s | 7.870 |  
|:-------------------------:|:------:|:----------------:|:-------:|:---------:|:-----:|  

From this table it is clear how, at least from a pure speed/energy point of view, JSB EXACT EXPRESS DIABOLO are the best domed pellets and RWS MEISTERKUGELN are the best performing flat head pellets.