I guess if you don't own a chronograph this probably doesn't mean much to you but I recently attained the lowest SD I have ever had in any gun I load for... and I have reloaded a dozen different calibers over the last decade. Last year, I finally bought myself a 308. Specifically a Howa 1500 with 20" heavy barrel. Not being able to leave well enough alone, I started reloading for it as soon as I had about 60 once fired cases in hand. As it happens the rifle likes both PPU's Match line and Federal's 168gr/175gr SMK GMM factory offerings. Naturally I bought some 168 SMK bullets and scoured the net for info. I wound up working with RL 15 and worked up a few loads. All of them(42-44gr) were MOA loads if I did my part behind the trigger but a node around 42.5gr seemed to be the sweet spot for me. I started exploring this range when I put down a .501" 5 shot group at 103 yards last month. I decided to do a primer test just to see if I could reduce my spreads a little within that area. The winner was a load of 42.4gr of RL15 using a Fed210 primer and PPU once fired brass that achieved an average of 2449 fps an ES of 4 and an SD of 1 ! Now technically I think the SD is 1.7 and the sample size was only 5 shots but either way, I'll take it. I have put together many accurate and consistent loads over the years but this one takes the cake. I didn't sort bullets, cases, turn necks, use match primers, just found that magic powder bullet combo. Overall that group was just over an inch but I haven't settled on a COL just yet and luckily the howas box magazine will allow bullet length near 2.890" which will put me well into the lands with just about any bullet out there. For any of you long rifle types I'm sure you'll appreciate the relevant data. It may not mean much at 100 yards but at 600 yards a few fps makes a difference. Happy reloading gents !