I got a chance to test out two different types of ammo in my 457 Pro Varmint today. I have been shooting the SK Standard Plus through it with fairly pleasant results. From local rimfire BR matches (shooting factory class), to stretching it out to 240 yards on steel, it has been pretty consistent.
I am somewhere between 750-800 rounds down the pipe now, with no cleanings. It is still continuing to tighten up and I am more open to trying different/better ammo through it. I ordered several boxes of SK Rifle Match and SK Long Range Match. Both shot well at 50 yards. I shot 5, 5 shot groups and then shot the 25 BR targets.** Groups were shot from a bench with Atlas bipod and sandbag in the rear **
I am going to move them back to 100 yards to try and make a final call on which one to load up on. Both ammos, with my rifle, are capable of 250 scores. The few that left the 10 ring, I knew when the shot broke. I am still loving the rifle and I’m very happy with it!