DKSDonnie
Member
I recently got back into reloading and started reloading for my WSM's. First, I have a Browning ABolt in 7MM WSM with a 23" barrel. I have read just about every post I can find on pressure signs. Some reloaders swear on the "Just forward of the extraction groove on the web" measurement, some swear by primer sign, some swear by bolt lift, some say watch your chrono speeds, some say watch it all, others believe in a couple signs and forget the rest. I'm going to watch it all. I have measured some factory Winchester Supreme casings that were never fired and at the web they measured .5485. I also have once fired in the same casings which measured at .5525 at the web. Now, from what I've read, you should see no more than .0005 and .0007 expansion with short mags. Hodgdon says to only measure new brass compared to once fired brass because measuring once is not accurate due to case hardening. Due to SAAMI specs, factory ammo is made to fit all rifles and if you have a larger chamber, you will have more growth than that. So I'm at .0040. Either the factory Winchester Supreme ammo is way over max or I have a larger than normal chamber or this expansion is normal when firing casings for the first time. Is Hodgdon is full of it? Should I be concerned? I've read where Winchester Supreme ammo for the WSM's is pretty much at Max loads. Hence the flattened primers which could be also caused by headspace on new brass. Some insight is much appreciated.