I'll throw in my 2 cents worth here. You did the right thing by cleaning out the barrel. Let's talk about some other factors. Knowing the way I shoot, 2" groups with open sights at 100 yards would be a good accomplishment for me, but if you think that's not tight enough, that's your perogative. Keep in mind, that this is a deer gun, not target rifle. As for your testing while the scope was on-did you cover all the basics then? Were all the screws tight? Did you check the scope for parallax? Sometimes old scopes just won't hold point of impact real well. You said the first scope was a 3x. That's not a whole lot of magnification, even at 100 yards. It wouldn't be hard to see how the groups could have been a little on the big side. I shoot factory ammo out of my 99s, and I've tried a lot of different ammo to arrive at consistent accuracy. My 300 that I usually carry likes standard Remington 180 gr. loads better than all others. Keep working till you find one that satisfies you. As for the bedding job, I wouldn't have done it, but that's just me. The only thing that touches my dad's 300 is oil, and Hoppe's.
