Brand new caliber: .296 bore 290 USA XP-100 (USA=Ultimate Short Action) built by Mac's Gunworks. Using a Matrix 198 grain VLD .296 (Estimated BC somewhere between .680-690). I haven't chronoed the load yet, but with a grain more of H-1000 it ran 2660 with 17.5" barrel. Settled on 65.0 grains of H-1000 and Fed match primer. 65.5 grains would give a slight swipe when we used a sharpie on the head of the brass. Once I have chrono #'s, I will plug everything in and then confirm my drops. Both chrono #'s and BC #'s are starting point. LR drop confirmation will give me a working solution, and I will tweak the numbers to make it match my actual drops. I do this with all my rigs. It would be nice to do this a couple of times before my SP shoot, but that won't happen this time 300 SAUM (Norma brand) brass necked down. Nitrided XP-100 action and barrel (bolt is not nitrided), action is trued, Dell trigger, Mac's new slotted design brake, reinforced H-S stock, 20 MOA pic rail, NF rings, and a Holland level. Pictured with a Vortex HS Viper (XLR reticle-MOA reticle) in FFP. I am 90% plus sure the scope went down. This caused a lot of frustration and time. Looking back I should have changed out the scope sooner, but it gave me about 80 rounds with me on on it using two different bi-pod's (Atlas & Harris) and a couple of different field bags. It has been replaced with a Leupold 6.5-20 Mark 4 FFP with ART reticle. Thinking it will chrono at 2600 fps. Doing that today and will be confirming some drops out to at least 800 yards. If this is the real MV, combined with the BC (still to be ultimately determines), it outruns my 7 SAUM, 7WSM, and 7 Rem Mag Imp SP's with 18" barrels with the WSM and Mag Imp having more capacity. I did the load development on these other rigs (the WSM was built by a friend out of state and 7RM Imp is a MOA Maximum) the same way as we have done with the USA. First 5-shot group after scope change yielded a 5/8" inch horizontal spread @ 100 yards, with only .104 vertical. Really impressed with the lack of vertical! Had some gusty cross winds, and there is a horizontal issue with the aluminum feet on the bi-pod I am using on the wood bench. Chuck shot this group after I left on Monday afternoon. I am enjoying this, and am looking forward to getting the USA's legs stretched out late this week and early next week. Why a .296 bore? Something new. Sort of a gap between .284 and .308. Throat life should be longer as well. How much? I don't know. It was designed for LR shooting and LR matches, possibly F-Open, and LR hunting. This is a work in process. This is not my idea or creation. I am honored to have the first .296 SP! Thanks Chuck for building a great Specialty Pistol! Using the SAUM as the base case is perfect for the XP platform IMO.