Earlier today, I received the slugs that I ordered a few days ago. I tested them earlier tonight.
31.8 meters, 5 shot groups
JSB Knockouts 0.217" diameter - This was the worst of the ones I tested tonight. 1" CTC groups. The spec says it's supposed to be 0.217" but they measure 0.2181" for most of them. Certainly not even close to 0.217"
Zan 20gr 0.217 - These were a little better than the JSB Knockouts but still unacceptable. 0.73" CTC.
Zan 23gr 0.217 - I didn't test these yet based on what I saw with the 20gr version.
H&N 21gr 0.217 - These shot ok but nothing spectacular. 0.48" CTC group that includes 2 flyers.
FX Hybrids - These actually had the same 0.48" CTC as the H&N 21gr but I feel it's more accurate. I felt that I pulled 2 of the shots. I will continue testing this one. 32 FPE with my gun.
H&N 23gr 0.217 - This is by far the most accurate in my gun. 0.155" CTC group averaging 801 FPS (32.78 FPE) in my gun. I'm very surprised that my gun likes the H&N slugs at all as I've never had any luck with their pellets in my TX200 nor my Taipan Veteran. I'm glad though because these are relatively easy to get and much cheaper than the FX Hybrids. Now, I don't know yet how these will perform at longer distances, but as I said previously, I'm really only planning on shooting up to 75 meters. If these remain sub-MOA at that distances, I will be very happy.
Interesting to note that the H&N 23gr is also the closest in diameter to the most accurate NSA 17.5gr slug. The NSA slug that was most accurate with my gun has a diameter of 0.2167". The H&N 23gr is 0.2168". Incidentally, the less accurate H&N 21gr were measuring below 0.2165" with some closer to 0.216".
In my testings tonight, I noticed that slugs seem to be far more sensitive to the way I pull the trigger than pellets. I'm not sure if it's because my gun has a 550mm barrel and the lock time between a 950 FPS Hades and an 801 FPS H&N 23gr slugs makes that huge a difference but I can't think of anything else. I have set up my Taipan's trigger weight to what I feel comfortable for a hunting rifle; not too heavy and not too light. I set it up completely by feel so I don't have any idea of its weight. If I had to guess though, probably around 15 oz. All I can say is that it's still heavy enough that sometimes I feel that I want to slightly jerk the trigger rather than letting it break smoothly. For the distances I'm shooting at, I've never really had too much issues doing that with pellets.
With the slugs however, I find that it's super sensitive to that bad habit. I really have to concentrate on applying a constant pressure until the sear breaks for the slugs to hit their targets.
Case in point, the H&N 23gr practically did a 1 ragged hole at 31.8 meters on the first group I shot with it. I did a few more shots with the other projectiles in between and I came back to the H&N again with a totally different mindset. I don't know if I was getting tired but I noticed that I was slightly jerking the trigger and the group really opened up. I didn't measure it but it looks to be 0.75" CTC. I concentrated again on the proper trigger pull and the accuracy of that particular slug came back.
Also, this is why I said above that I feel that the FX Hybrids can be a bit more accurate. It's because that was the first group I shot so I wasn't fully aware yet of how I was pulling the trigger and just how sensitive the slugs are to improper trigger pull.
