Yes they are a very heavy natural shaft being just a shade over 5/16" thickness.I shoot close to 700 grain shafts here many times[dogwoods,footed douglas fir,and believe it or not multi flora rose is over 700 grains too],but now they are all 11/32" to 23/64".These will be into the 700 to 800 region.Thinner,and around 30" long.I will keep you updated.