Disclaimer: I'm fully aware that with NO published load, this is a crapshoot starting out on a blind load. I'm fully aware of the inherent dangers of reloading in this manner, in any aspect of reloading ammunition. Now with that out of the way. I'm thinking of doing some development on an unpublished load. As the title says I'm considering looking at the .300 Blackout and Titegroup. Why Titegroup? I'm looking for a lower cost powder drop. Trailboss currently is the lowest charge powder, but also has absolute crap results. Rifle Specs Make: Remington Model: 700 AAC-SD Rifling: 5R Barrel Length: 16.5 Now that we have established that I don't have to worry about back pressure to cycle an AR bolt and this is in a bolt gun.... the world is my oyster and this load is my pearl.. right? I'm considering working up some 110gr plinkers, maybe even some 150gr ones as well at some time soon. Here are a few things I have considered to try and start my "educated guess" on where to start with such a blind load. 1: Case capacity. The idea is to find a case that's close to the same as the .300AAC and has a known and published load with a similar bullet weight (110-220) 2: Pressure: Verify the pressures of that load that's similar in capacity, with similar weighted projectile. 3: Barrel Length: While this may not be as much of an issue, using a longer barrel will mean that most pistol calibers are using less barrel to propel that projectile out of 3-6" of rifling with X velocity. 4: Starting Point: I am finding that there are those using 4-6.5gr's for 220gr subs out of 7x62x39, PUBLISHED LOADS: .308 specs show 8.0 in 220's at subsonic, .223: 3.1 in a 55gr, .44 Magnum: 5.3gr in a 165gr load. Yes case volume has a LOT to do with pressures, hence the .357 and .38spcl setup. Same powder, same charge, same bullet and one goes bang while the other goes bang. 5: Detonation: Myth or fact? If this is true it's something I want to be aware of and alert to it. Magnum primers or not... While powder manufacturers say it cannot/does not happen, the idea of it still floats around. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ With that said and all disclaimers aside. I was planning on doing the numbers, finding the case with similar capacity, similar bullet weight, then loading DOWN from there not 10%, not even 20%, but probably more like 25-40% as a starting point. Currently the .300 AAC on 110gr loads that I'm going with using IMR4227 have a published 46,700 PSI. If I undertake this, any advice or is there something major that I'm overlooking? Get bullet out of barrel, check pressure signs, slowly work up (I'm thinking .1gr or .2gr at a time while checking to ensure the bullet has left the barrel after every shot in the lowest loads). Crazy? Nah. A tinkerer? Yes. Remember I'm considering, this doesn't mean I'm going to jump in today, this afternoon or tomorrow and quickly in haste make up loads for this. I've been looking into this for a while now so I wanted some technical views from fellow NW'ners. Constructive criticism is valued.