Hi everyone, -Background- I put together a bunch of parts over the years for a "big boy" hunting rifle built off a $50 Pawnshop Savage. While the 28" Proof 7mm Rem Mag barrel was a lot of fun, it was wholly impractical for 99% of the hunting I do. Earlier this year, I celebrated a new job, new baby, and new house by sending the rifle to my gunsmith to be rebarreled in 30-06 using a Rock Creek blank. Rocks have always shot well for me, usually are pretty speedy and require very little care. Since I exclusively hunt with silencers (this one wears a TBAC Ultra 7) and I like a handy(ish) mag fed bolt gun, I elected to have the barrel finished at 18" to match my other handy hunting rifle - a Ruger M77 MK II in 243 Win finished at 18 inches. I've found this length with a can to be reasonably handy in and out of trucks/UTVs and walking around the woods. Why 30-06? Why not? Easy to source components. Easy to reload. Easy to find factory ammo anywhere and everywhere. Capable of killing darn near everything in North America. I reload for every rifle I own, but my chances of finding wildcats in a backcountry Wally World are pretty much zero. This is a tool and as such, it needs to work all the time, everywhere. -"Don't go that short. It'll be worthless" My gunsmith, friends, and strangers tried to talk me out of it. Told me I was crazy. Look at all that velocity I'd be giving up. I took book values which were based on 22" or 24" barrels, cut 25 fps/inch, and plugged those numbers into my ballistic calculator. I figured if I could get 2500 fps or better out of 180 class projectiles, I could sleep well. That'd give me a quarter mile of effective range (1800+fps at impact) pretty much anywhere. 2769 fps was Nosler's book max for a 24" barrel shooting 180's using H4350. 2769 - (24-18)*25 = 2619. I felt confident. -Component Selection- I elected to go with the 180 gr. Nosler BT. The BT's have always been strong killers for me, they can be found almost anywhere, and load data is plentiful. The 180's buck the wind better than the 150 class and I'm a terrible wind reader. For powders, I wanted to try H4350 and RL16. Both have proven to be very temp stable. RL 16 is more temp stable and usually produces higher velocity, but seat of the pants, H4350 has always shot better. My local reloading shop had Winchester brass on the shelf so that's what I'm using. I might go with something stouter if I don't see good life out of these, but for roughing in loads, it serves me well. CCI primers are all that I can get my hands on so I'm using the standard LR primers. -Throating and OAL- Even though I'm using generously large magazines with this rifle, I didn't want to throat it super long so I stayed with a "standard" throat. Loading the 180 Nosler BT to the book OAL value of 3.330, I measured jump at a shade under 0.040" - I loaded them .020" off the lands and called it good. -Testing Procedure- I like to do my first round of testing to narrow in on what I loosely define as the "boundaries" of what's possible. I load up maybe 15 or 20 rounds at incrementally different charges, strap on the magnetospeed, and blast into a berm or backstop until I start seeing flattened primers. This does 3 things. First, it helps me establish an upper limit on where I'll see pressure signs. Second, it allows me to get a realistic look at the kinds of velocity I'll be able to see from a powder/projectile combo. Last, I can look for bands of "flat velocity" where incremental powder charges don't seem to affect velocity much. Phase 2 is to load up 14 rounds at potential sweet spot loads. This lets me pull 5 rounds for velocity so I can look at average velocity, SD, and ES. That leaves me enough rounds for 3 groups of 3 for accuracy. I've completed Phase 1 and hope to have Phase 2 completed in the next few weeks. *****Please keep in mind that the data here is for my rifle and my rifle alone. Do not replicate in your rifle. You could be seriously injured or even killed***** Below is graphical and table data from my Phase 1 experiment. None of my loads showed pressure signs at the primer. You can see from my highlighted areas that somewhere between 2600-2650 fps seems to be a nice little sweet spot. I've now loaded up 56.0 gr of RL 16 and 56.7 gr of H4350. I anticipate that velocity will likely be 2620 and 2605 respectively. Keep in mind that Noslers book lists 2769 fps as max velocity using H4350 with the 180's. I'll update this post once Phase 2 is complete.