https://www.ballisticstudies.com/Kno...Practical.html
I have just finished load development for a 7mm Practical with the latest version of the Manson reamer, also using dies from Manson Reamers. The first thing I will point out is that the 7 Practical is not just a 300-7mm. The reamer was designed to produce a 30 degree shoulder and a longer neck, allowing the cases to grow through firing. Although not mentioned in the article above, a longer neck will protect the throat area from additional erosion by redirecting the gasses longer before they make contact with the throat.
The cartridge design is extremely thoughtful and this leads to a very accurate and effective cartridge that does everything better than all the other big 7's. Just like many precision shooters gravitate to the more accurate cartridges such as the 6.5X47 over the larger, faster cartridges like the 6.5CM, the 7 Practical provides long range hunters with a cartridge that is more efficient and more accurate than its rivals.
My platform is a long action Savage with a 28" Krieger Heavy Varmint barrel. I am pushing 180 ELD-Ms at 3190 and these rounds are producing 1" groups at 300yds. During initial load development I fired 6 rounds at .5 grain intervals into 1.5" group for my initial ladder test. The brass I used for this ladder was not even fired form yet. This further illustrates the inherit accuracy of this cartridge.
Although the 180 grain bullets don't carry the same weight of the big 30's out there, the ballistics between the two are no comparison....at least until you get to the 300 Norma and up. The 7mm is just an amazing projectile that seems overlooked all too often.
I will continue to work with this cartridge and if I have any additional information I will share it. Feel free to hit me up with any questions.