Reloading data for 7x57 in strong modern action?

[CO hunter]

I bought a new CZ 550 American chambered in 7x57mm last spring and am really pleased with its performance and all other aspects of the rifle. Using a variety of factory ammo (139, 140, & 175 gr) I consistently shoot moa or better off a bench out to 200 yds. The rifle doesn't seem finicky and shoots tight groups with all the factory ammo I've tried. I'd like to begin handloading for the rifle and while the mild factory loads are pleasant to shoot, the strong CZ Mauser action is capable of handling higher pressures than the old 1893 Spanish Mauser that I've had since I was a kid. So, I'm looking for advice on where to find information on developing safe loads that tap into the potential of the 7x57 shot in a strong modern bolt rifle.

 

[Jud96]

Check out Reloader's Nest - a reloaders resource they have loads for all of the bullet weights you mentioned that are developed by users of the website. Each load lists what components were used and what type of rifle the load was used in. Just searching through the 7x57 section quickly I found a couple high velocity loads that were developed and shot out of a modern rifle. I hope this information helps out. Good luck with your 7mm! This cartridge is one of my favorites and I plan on building a classic Mauser sporting rifle in the caliber this year.

 

[CO hunter]

Military Rifle Guy, This is just what I need. I've shot a full range of center fire calibers, since I bought a sporterized 1893 Mauser from a local gunsmith decades ago to use as my first "deer rifle". However, I keep coming back to that sweet 7x57 so I was really motivated when I ran across the new CZ 550 in the caliber last year. It will be fun to explore the potential of this old caliber in a well built modern rifle and your link is a key to doing that. Good luck with your Mauser sporting rifle project. Thanks!

 

[westcliffe01]

Like usual, you can go to the Hodgdon powder website http://data.hodgdon.com/main_menu.asp follow their recommendation and keep increasing the load in 0.5gr increments until you start seeing pressure signs. Try using powder that is not temperature sensitive or else you may have to re-check your load next summer (with caution). If the primer is the limitation, you might consider going with mil spec primers that are harder (made for semi auto rifles).

Also try to determine how far out you can seat your choice in bullets in the magazine and throat. I recently loaded my first 8x57 loads using the 196gr Hornady HPBT bullet and I was quite surprised that the throat severely limited the OAL of the cartridge. If I am going to stay with this bullet (one of the few that is available in 8mm) then I may need to re-cut the throat deeper by quite a bit so that the magazine becomes the limiting factor. That extra length will probably allow me a reasonable amount more powder in the case which I could use in the 26" barrel.

 

[Jud96]

I'm delighted to know that I have helped you out! The 7x57 cartridge is excellent and definitely one of the best rounds ever. The 7mm Mauser is a great shell to keep coming back to haha, especially in a modern rifle. It will surely exceed the 7mm-08 with the hotter loads out of your CZ. I also plan to purchase a Remington 700 Classic in 7x57 which will be a fantastic rifle as well in this caliber. Thank you for wishing me luck with my sporting rifle and I too wish you luck with you 7x57!

 

[benchracer]

Some of my favorite cartridges have issues with availability of good, modern loading data. I have a Ruger #1 in 7x57, so I feel your pain. One thing I have done is to compare my loads to 7mm-08 data. There are some limitations to this approach, but it can at least serve as a guide to tell you if you are in the ballpark.

Another step I am planning to take is to buy a copy of Quickload and a Chronograph. I expect that having those two tools in hand will go a long ways toward helping me get the most out of the cartridges I am loading for, while helping me to avoid going too far.

One thing I have discovered in my progression as a handloader, is how limited the data really is for all but a few of the more common cartridges. It may simply be that handloading has caused me to gravitate toward a different set of cartridges, but it seems like my favorites all have gaping holes in available data.

 

[Jud96]

Ya benchracer, a chronograph is a need in my opinion. Loads velocities are sometimes completely different when tested in your rifle compared to the book's.

 

[CO hunter]

Great advice. This gives me plenty to run with. Thanks guys!