I have a Thompson Encore, with 3 barrel.
I love this rifle, BUT !!!
With the 22-250 barrel top with the 4200 6-24x40mm
Once i acheived a 0.25 inch group...ONCE!
Most of the time it played around 1 inch to 1.25 for 3 shot at 100Meter
Really, it did'nt satisfied me.
AND, I've tryed some different ammo, Win-Fed-Rem.
And everytime you change of brand youre Vertical Plays a LOT...
From the 50gr Rem to the 50 gr Win, the Winchester shoot 6 inch higher at 100meter, just as example.
So i bought a Bolt-rifle, i've try the same things: shoot different ammo brand..AND now it goes almost at the same spot whatever i shoot !.
But if you always shooting the same ammo, not a problem, you shoud be able to do 1 inch group average.
The blackpowder barrel Shoot great.
And the 7MM shoot the same: Average 1.0-1.25 inch. But again, the vertical story with the different ammo brand.