20 gauge is just fine for taking deer. If it works for you keep using it.

I used a 20 ga 870 wingmaster with a fixed modified choke when i was younger, now i use a benelli sbe 12ga, one of the reasons i bought the benelli was it felt a lot more like a 20 ga, weight, mass etc; just felt good in my hands, however it doesn't kill deer any better than my old 870, now turkeysare a different story and i prefer the 12 for pheasants.

I just looked the muzzle velocity for a 20 ga slug compared to a 12 ga slug. The 20 ga is faster, which means it shoots flatter, which means you could take longer shots. The 12 has more weight, but how big af a bullet do you need to kill a deer? If it drops deer I wouldn't change.

Nicely Said...