8tw will be enough for probably all but the longest monos. You can get away with a slower twist rate if you can make up for it to certain extent with increased velocity.I am looking at 6.5 PRC as my next hunting cartridge. Seems all the makers except Browning are a 1:8 twist rate with them using a 1:7. How fast is too fast for 6.5PRC with 147ish grain rounds?
You’ll get more responses if you create your own thread.Not trying to hijack the thread, but building on @Nicaburns question... is anyone running more than 3000fps on the 147gr bullet in 6.5PRC? And here's the hijack part, would running a 3080fps velocity out of my short barrel 21" @1.8 twist (Seekins Element) be a bad idea?