Hydenseek : I went thru the same thing as you , but it was about 30 years ago . I have taken Pdog Trips almost every year after that . For up to 500 Yards ( mostly 150 to 450 Yards ) , I settled on a Reworked Rem 700 in 223 . I shot various Bullet weights from 40 to 55 Gr. and various Powders . I finally settled on using a 1:14 Hart Barrel and 40 Gr. Vmaxes with either H322 or AA2015 BR Powder ( toss up for Accuracy ) with CCI BR Primers . V133 Powder was also great , but I had plenty of the other two Powders on hand . The Brand of Brass never made much difference in Accuracy with this Rifle and included Win , Rem , IMI , Guatemalen 223 , PMC , and others I can't remember right now . The 12 Pound Rifle is Muzzle Heavy with about 0.94 inches Diam. at 26 Inches , but is exactly what I wanted for a home-made stand-up ( or sit down ) Tripod . I walked around carrying the Heavy Rifle , Tripod , Water , Ammo , Binocs , Rangefinder , and even a fold-up lawn chair for many years . Shots out to about 400 Yards ( or a tad more ) were easy . When I got tired walking , I used a 3 Legged super sturdy Bench built by a guy called Dogbuster ( if I remember correctly ) . Even though I have all sorts of Scopes , I favored a 16X Leupold . I have helped Friends install Bases on a lot of Rem 700s and 2 Piece Bases were always way out of Alignment ( using Brownell Pointers ) . We all went with I pc. Bases . I used all sorts of other Calibers ( Swift , Roberts , 6mm , 243 , 222 , etc. and have a 6.5-06 Ackley for Long Range which I have never used . I was hoping to take one last Trip out for Pdogs , but don't know if I will ever have the opportunity and energy anymore to go out and find good places to shoot . I know my Hart Barrel has over 10.000 Rounds thru it ..... all in the Pdog Fields . I kept very loose records but my Average shooting was about 200 or 250 Rounds per Day , but have heard shooting is down quite a bit lately . If I were going to stretch out the Range to 600 or 700 Yards , I would go with the 53 Vmax in a 223 AI , one of the Hotrod 20 calibers with heavy Bullets , or one of the 6 BR variants . Good Luck !