7x57 & 175gr SBT Sierra GameKing

[Slamfire]

Developed a load for my 7x57 with the 175gr SBT GameKing using a near maximum charge of Re22. Top muzzle speed is achievable with this powder and bullet weight according to the Woodleigh loading manual and Speer No.12. Chronographed at about 2575 fps and groups about 1" off the bench at 100 meters. This rifle has a 20" 1:8.66" twist barrel.

Also off hand accuracy as shown which is the real test once the rifle is sighted in.

7x57 Zastava LKM70 Carbine with Bushnell Legend Ultra HD 1.75-5x32mm

 

[diananike]

Whoa.
Seems a little stiff for my Spanish Mauser as it's on a 93 action.
Too bad as it only likes the heavy bullets...

 

[Slamfire]

SAAMI specified maximum pressure is 46,000 cup in deference to the weaker Model 93 and 95 Mausers. The load I'm using in my modern 7x57 rifle safely exceeds that pressure level according to Speer No.12.

For comparison, muzzle speed for Federal Power Shok 7x57 175gr ammo is listed as 2390 fps, likely in a 22" or 24" barrel. 200 fps faster with a 20" barrel is a significant improvement.

https://www.federalpremium.com/ammunition/rifle/family/power-shok/power-shok-rifle/7a

 

[TangoKilo]

Awesome cartridge and a very nice load you have there.

Back when I shot a lot of 7x57 I used an almost identical load.
175gr Sierra with LOTS of RL-22

I'm wondering if the new RL-26 would buy you another 150fps in this cartridge, or if it lacks the capacity to get there.

 

[todbartell]

RL26 should work well with the 175gr class bullets in the 7x57. Looks like in a modern rifle, 60k psi pressure level, 2800 fps is possible from a 24" barrel. Now when you think about 7mm Mag factory ammo rated at 2860 fps MV, it puts that load into perspective! 20" barrel would still net 2700 fps, loaded down to 50k PSI you'd be in the 2500 fps 20" / 2625 fps 24" ballpark

 

[Slamfire]

The 7x57 seems to use powder rather efficiently. Barnes No.3 also lists Re22 for top muzzle speed with their 175gr bullet and 2nd highest muzzle speed using IMR 7828. Classic round.

 

[dgradinaru]

My Ruger #1 with a 22 inch barrel is running the 175 hornady interlock at 2575 fps with a stiff load of imr 4350 and mag primers. Looking forward on trying my cz 550 with the 23.6 inch barrel. Hoping for 2625 fps.

 

[Slamfire]

With a 175gr looks like 163 fps more muzzle speed using Re22 compared to IMR 4350 according to Speer No.12. Handloaded a No.1 7x57 should be capable of impressive muzzle speeds.