I've been thinking about some loads. For what it's worth: these are being shot out of a Remington 700 AAC-SD (16.5" barrel with 5R rifling) I want interchangeability for my other .308 caliber rifle (300 Savage) for bullets. Since the .300 Sav uses anything up to and under 150gr bullet's I should be doing just fine. My preferred round for the .300 Sav is a 150gr Sierra Pro-Hunter. I'll start with those. So I'm looking up specifics for that loading plan and Sierra shows 2.105" OAL with their bullet. (see: https://sierrabullets.files.wordpress.com/2013/07/300-aac-blackout.pdf). Their range of powders show H4227. Now I use IMR4227 which for all purposes is similar (not identical mind you). Hodgdon Says: that with my IMR 4227 I'll be using 16.5 to 17.8gr with a 150gr bullet (jacketed). Very similar in loadings (16-17.5) with the H4227. Now their OAL doesn't match Sierra's obviously because it's not the InterBond Hornady. So I'll use the Sierra length posted. My intent is to start at the 16.5gr and work up in .2 or .3 grain increments until I find that sweet spot for that load. Document it and then mass produce it like I've done with every other rifle. Adventually I wouldn't mind going to a 125gr for the final supersonic, but right now I'm keeping everything supersonic because of bullets that are on hand. Subsonic shouldn't be too hard after that. Now, here are some questions: Since this isn't the first rifle I've reloaded for.. is there any benefit to (since it's in a bolt rifle) to only neck sizing the .300AAC?