At the op , iv had a std 223 & 223Ackley , have had a 20p for some years and honestly for varmints its the dogs . I prefer it to the std 223 & 223Ackley . The ackley was 8 twist shooting 75 Amax . But i replaced that with 6br so have a 400 yard 20p and 6br does alot futher . Id like a small 17 for 200 yard quiet gun but haven't done much about it yet a few years on . The 20s are less likely to ricochet than a 75 Amax too so in that respect , similar to say 17 rem - seem safer. 20s are devastating on crows etc