It works better than any tool you can buy, marks and measurments only still get you close, but with a bit of fuel line it's easy to find the best spot and you can find leaks by putting a empty case in the chamber, and a finger over the end of barrel, then test air pressure again.Originally Posted By: 4seasons69That is a good idea. I will bring some vacuum hose from work home to test it. I fear if they aren't lined up good enough now I will either need a different gas block and or gas tube