I have been shooting long range (1,200 yards) for over 30 years and have became very proficient out to that distance.
I am in no way handicapping myself by using a handgun, especially with the gun and cartridge that I shoot. 2" groups or less at 300 yards from a bench are the norm, and if I cannot get a good solid rest out in the field, under no circumstance will I pull the trigger!
I'm not the best shooter out there and don't claim to be. I just take great pride in my shooting ability, as well as time taken at the loading bench.