22/243 is a 900 round barrel, maybe 900 if you don't abuse it, carbon fouling rascal to keep up with, great on range with slippery v ld bullets, not a gopher rifle. 243 Middlestead is a great improvement over the 22/243 in that you just run the brass through the die and it is formed. 75's at 3600 in the Middlestead is ho hum with R#17, again, not easy on barrels.
22 Creed is easy peasy.
Swift on ground squirrels, 15-16g of Blue Dot with 40g v max is hell on wheels at 3200 depending on your barrel length, with indefinite barrel life, clean every 600 rounds...work up to this load....weigh every charge or back way the hell off due to powder bridging in the powder measure with large flake powder.
Powder bridging = one light load, with the next a heavy load. 18g of Blue Dot in your Swift will probably lock your bolt up with brass flowing and completely blown primer pocket...hope you are shooting a Rem 700 or Winchester if this happens to you where the bolt heads are Rated at 150,000 PSI.
I have always wanted to go to Alaska and shoot some of those hoary marmonts(largest species of Rock Chuck) that weight up to 45 lbs! A friend went up to Alaska and shot the large Rock Chucks, they saw Grizzley bears slinging boulders digging them up that weighed over 100 lbs. He killed some that were as big as beavers around here.
