If anyone wants to chime in with velocity numbers on 250 grain ATIPs or 212 ELDXs, I am very curious. I looked long and hard at a .300 PRC, but running numbers in Quickload and looking at published data, I couldn't justify moving on from a .300 WSM even in a ground up rifle build (which I already have quite a bit invested into, so I was biased).
The .300 WSM will push 225 AMAX bullets at 2800 from a 29" barrel at short action AICS mag length (2.950" with the thinnest stainless magazines you can get). That requires that a lot of the shank be inside the case, which means that trimming the neck/shoulder junction is required. I actually use .300 PRC length (3.8") MDT magazines for my long action .300 WSM which is built around 250 ATIPs, but I do not have velocity numbers for that yet as I am 1) working too much and 2) bulk fireforming cases first. Predicted is between 2700-2750, thought Quickload is more of a safety tool than a velocity predictor. When I have actual chrono data for my the long action length 250s (IIRC 3.3" OAL to keep the start of the boattail JUST above the neck/shoulder junction) I can post it here for any who are interested.
I have no interest in starting a cartridge war as I am of the opinion that NEARLY ALL cartridges that area available today are pretty darn good, but we have an embarrassment of riches in .300 magnums these days. While I was very excited that the .300 PRC got rid of the .300 WM belt, I was genuinely frustrated at the OAL. Specifically, the whole idea with the 6.5 CM was to build a .260 Remington that would fit long bullets in a standard short action. A .300 PRC built to allow a 250 ATIP to be seated with the shank above the neck/shoulder junction with a 3.34' or 3.6" OAL still would've had a TON going for it over the .300 WM. NO belt, a fair increase in case capacity given the blown out case, slightly longer body and sharper shoulder, and a more efficient short/fat design which really does reduce recoil. But more than that, it would've allowed standard long action or magnum length rifles to become competitive again in the same way that the 6.5 CM resurrected the short action. It is possible that dropping the bullet diameter to 7mm might've been necessary to fit a 3.34" max OAL, but .308 probably would've been fine in a 3.6" max OAL.
I guess my critique is that if you are clean sheet designing something, and you decide that the only way to meet your targets is to exceed a dimension that has been a standard for over a century, then you need to GET a lot of concrete benefit in return for breaking compatibility. If you built a laptop with no USB ports in favor of a new cable standard that is faster, it needs to be more than 110% as fast. People with .300 WMs criticized the .300 WSM for the same thing 23 years ago: It is insufficiently better to justify a new case, BUT the .300 WSM had the benefit of fitting into a bog standard short action with only a blown out bolt face. A lot of my .300 WSM magazines are .308 magazines that were converted using a aerospace grade tools wielded by a skilled artisan (actually me using a pair of pliers and 3 dummy rounds in about 10 minutes per magazine). The point being, the .300 WSM uses a magnum bolt face in a short action, but doesn't break any big standard dimensions.
The point of my comparison is twofold: 1) a direct velocity comparison helps folks to decide what is best for them and 2) to vent about Hornady's decision to deliberately break action length compatibility standards with the .300 PRC. Rather than calling Hornady names (I have family that works there and I use almost exclusively Hornady components and tools), the more mature criticism/learning experience is a simple comparison of performance numbers. Thus my initial request for .300 PRC velocity numbers so that we can compare them with real world .300 WSM numbers. I think that objective comparison would allow folks to make their own subjective decision "Was this gain worth creating an entirely new category of rifle action length?".
