If you're in Mars, we're 2 hours away at Tusco Rifle Club immediately east of Midvale OH. We have a monthly steel shoot April through November which is open to the public and we always have lots of Class 3 stuff show up. The rest of the time the range is members only but there are no restrictions on full-auto and very few on the firearms permitted on some of the ranges. .50 BMG is restricted to 2 ranges and anything bigger to only one. https://www.tuscorifle.org/
If you cannot find anything in the greater PGH area you might consider driving over. And yes Form 20s are a PITA but you can file one for the year.