300+ Yards? What is your target an abandoned barn? Expect 10-20moa groups and huge scope elevation erector assembly. It can be done, and has but its not anything like a PB. You will need expensive equipment, ammo, compressor, etc. A Gauntlet 30Cal isnt going to get you where you want lol. But yes, a Texan or a full built Impact are decent options. 35Cal is also a good option, assuming you can hit the max stable speeds of ~1070fps. But you are realistically looking at several thousand clams to ring steel at 300yds with any consistency. For reference my fully built MK2 Impact slugger in 25Cal is maybe a 200yd max target setup. For hunting my max range is much closer, and my rifle has been a reliable sub moa puncher. Not normal to get a pcp under moa, especially further than 100yds. Most airguns will shoot tiny groups up to about 50yds, and the challenge gets frustrating at longer ranges for most people.