RonS: I'm a very active varminter (Beldings Ground Squirrels/Rock Chucks), own five .20 cal varmint rifles (and ooodles of .17's & .224's). The 20VT is far and away my favorite these days for work out to 500 yards. All the previous comments are spot-on regarding the merits of the 20VT. Think of it as a small version of a PPC.
As stated, the 20VT is based on the 221FB case, but blown out to a 30* shoulder from the parent case 23* angle, so it gives slightly more powder capacity, maybe better burning characteristics, but the accuracy is stellar in every rifle so chambered I'm aware of.
Here's a comparison of the 204 Ruger and the 20VT, both loaded with 32gr SBK's:
I've been shooting 650 pcs of reformed and annealed R-P 221FB brass, some have been shot six times (neck-sized only now), and they're still going strong with tight primer pockets. Adam Bently here produces the very finest 20VT brass, reformed from LC 5.56 cases, and his brass should last virtually forever in a 20VT with any sane load.
As for accuracy, my Cooper M38 Varmint will shoot the 32gr SBK into .25" most days, and the 32gr NBT into the .3's with my usual load of 18.5gr/RL-7 @ 3,725 fps.....what's not to like? A typical target shot in the field:
And as we all love gun-porn, here's a field shot of my 20VT doing what she does best......make life difficult for the local rock chucks, and put a smile on my face, all at the same time.
See all your hits/misses, miserly on powder, very mild blast (almost could be called 'quiet'), zero felt recoil and
wicked accurate. Don't confuse the 20VTT with this one.....BIG difference; Advantage: 20 VarTarg.