7x57 at Modern Pressures

[Clint08]

I have a Husqvarna 1600 I had chambered in 7x57. The rifle will be used for competition as well as elk hunting. The intent is to use the Hornady 175gr ELD-X for both, so essentially the competition is serving as practice before hunting season. Rifle is a long action and PTG bottom metal was added so seating depth options are unlimited. My original intent was to use match 160s but the throat was cut longer than I was expecting during the rebarrel. I’m hoping someone can run some QL predictions to compare to my GRT predictions. Since the barrel is 1:9 twist my thinking is the velocity needs to be above 2600FPS at altitude to be above marginal stability. GRT prediction is 1 grain higher to reach 60,000 PSI and 2680FPS. Since this will be used for competition I don’t want temperature changes to push me over pressure during a match and would like to stay at milder pressures. 60,000 PSI loads or slightly under would seem to offer a little room. My next range outing I will be using 44.8 to 45.2 in .1gr increments to look at SDs. I’m inclined to disregard the primer protrusion referenced below because of the quality of the brass being used and knowing some primer pockets were loose during first loading. Case expanded .002 at the headspace datum line at 45.8gr but no expansion was observed below 45.6gr. Obviously these loads exceed book data by a considerable margin but the COAL also is well above referenced data and the action was designed modern pressure. Thanks

Bullet: Hornady 175gr ELD-X 2.577 CBTO, 3.300 OAL
Land Contact at 2.597 CBTO
Primer: CCI BR2
Brass: Winchester Case Capacity 60gr H2O
Powder: H4350
Barrel: 24in, 1:9
Temperature: 70F

43.0 2516
43.2 2512
43.4 2531
43.6 2559
43.8 2558
44.0 2547
44.2 2577
44.4 2600
44.6 2605
44.8 2632
45.0 2629
45.2 2646
45.4 2654
45.6 2683
45.8 2684 Primer protrusion .002

 

[nakneker]

Can’t help you on the information you’re asking about but I can compliment you on a great looking rifle. Those old Husky 1600s are neat actions, I’ve had a couple over the years. Nicely done.

What stock is that by the way?

 

[Clint08]

Can’t help you on the information you’re asking about but I can compliment you on a great looking rifle. Those old Husky 1600s are neat actions, I’ve had a couple over the years. Nicely done.

What stock is that by the way?

Bell and Carlson Mauser 98 stock. The tang on the Husky sits deeper and glass bedding fills in to compensate for the large to small ring receiver.

 

[std7mag]

You have the case capacity, and your using a heavier bullet.
Why not use a slower burning powder?

 

[SeabeeKen]

Very nice rifle. I have a Ruger M77 with Kreiger barrel chambered in 7x57ai that I love. Took a LOT of game with it. It shoots very well with the 8.5 twist. I also push mine to the 60,000 psi limit with PPU brass

 

[Murray Brook]

The 7x57 is a great cartridge. In a modern bolt action rifle there is nothing that the 7/08 Rem (which I love) can do that the 7x57 can't do or do better. That is a very nice looking rifle that you have. JMO

 

[ben-o]

Have you compared data for h4350 and that bullet in 7mm-08 and 280 rem? It seems like you should easily hit 7mm-08 velocity, and the max would be somewhat less than what the 280 rem can do.

 

[Clint08]

You have the case capacity, and your using a heavier bullet.
Why not use a slower burning powder?

I was considering that but just bought the 4350 for workup using the 150s and 160s. I’m completely satisfied with 2600-2650 range with 175s and I’ll only be shooting from 300-900 yards. I don’t want to push the limit too much and was curious what pressure prediction QL had for the combinations listed. Thanks for the reply and I will try some 4831 in the future. I’ve always used 4350 for medium weight and 4831 for heavier bullets in almost every cartridge I load for but I just started on this new lot of 4350 I bought a large batch of.

Have you compared data for h4350 and that bullet in 7mm-08 and 280 rem? It seems like you should easily hit 7mm-08 velocity, and the max would be somewhat less than what the 280 rem can do.

That is exactly what I did and how I determined powder charges for testing. I was just posting this to see if someone with QL could run the data and provide a prediction. I have GRT and velocities have generally always matched in the predictions. They matched this rifle previously with 150s and 162s but I just switched to a fresh lot of 4350 and this lot was giving 60-70 FPS more on the same loads.

 

[Zero333]

Quickload estimate...
=========================
Cartridge : 7 x 57 mm Mauser
Bullet : .284, 175, Hornady ELD-X 2841
Useable Case Capaci: 51.353 grain H2O = 3.334 cm³ ( 59.5 gr H2O total capacity )
Cartridge O.A.L. L6: 3.300 inch = 83.82 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Hodgdon H4350 *T

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 81 37.60 2133 1769 32124 7330 91.8 1.643
-18.0 83 38.54 2183 1852 34198 7547 92.8 1.599
-16.0 85 39.48 2233 1938 36402 7758 93.8 1.556
-14.0 87 40.42 2283 2025 38733 7961 94.7 1.512
-12.0 89 41.36 2332 2114 41187 8156 95.5 1.469
-10.0 91 42.30 2382 2205 43783 8343 96.3 1.428
-08.0 93 43.24 2431 2297 46541 8520 97.0 1.388
-06.0 95 44.18 2481 2391 49471 8688 97.6 1.350
-04.0 97 45.12 2530 2486 52585 8845 98.2 1.313 ! Near Maximum !
-02.0 99 46.06 2578 2583 55898 8990 98.7 1.277 ! Near Maximum !
+00.0 101 47.00 2627 2682 59424 9124 99.1 1.243 ! Near Maximum !
+02.0 104 47.94 2676 2782 63179 9246 99.4 1.210 !DANGEROUS LOAD-DO NOT USE!
+04.0 106 48.88 2724 2883 67181 9355 99.7 1.178 !DANGEROUS LOAD-DO NOT USE!
======================================

47 gr
101 % case fill
2,627 fps
2.682 lb-ft energy
59,424 PSI chamber pressure
99.1 % powder burned

 

[Zero333]

Forgot to mention,... Winchester brass can take high pressures like no other,... You would probably not notice any pressure signs until you're around 70,000 psi.

I don't see any issues with stability. Just aim and pull the trigger.

 

[Clint08]

Quickload estimate...
=========================
Cartridge : 7 x 57 mm Mauser
Bullet : .284, 175, Hornady ELD-X 2841
Useable Case Capaci: 51.353 grain H2O = 3.334 cm³ ( 59.5 gr H2O total capacity )
Cartridge O.A.L. L6: 3.300 inch = 83.82 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Hodgdon H4350 *T

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 81 37.60 2133 1769 32124 7330 91.8 1.643
-18.0 83 38.54 2183 1852 34198 7547 92.8 1.599
-16.0 85 39.48 2233 1938 36402 7758 93.8 1.556
-14.0 87 40.42 2283 2025 38733 7961 94.7 1.512
-12.0 89 41.36 2332 2114 41187 8156 95.5 1.469
-10.0 91 42.30 2382 2205 43783 8343 96.3 1.428
-08.0 93 43.24 2431 2297 46541 8520 97.0 1.388
-06.0 95 44.18 2481 2391 49471 8688 97.6 1.350
-04.0 97 45.12 2530 2486 52585 8845 98.2 1.313 ! Near Maximum !
-02.0 99 46.06 2578 2583 55898 8990 98.7 1.277 ! Near Maximum !
+00.0 101 47.00 2627 2682 59424 9124 99.1 1.243 ! Near Maximum !
+02.0 104 47.94 2676 2782 63179 9246 99.4 1.210 !DANGEROUS LOAD-DO NOT USE!
+04.0 106 48.88 2724 2883 67181 9355 99.7 1.178 !DANGEROUS LOAD-DO NOT USE!
======================================

47 gr
101 % case fill
2,627 fps
2.682 lb-ft energy
59,424 PSI chamber pressure
99.1 % powder burned

Outstanding! This group is awesome and I really appreciate the QL prediction. It fairly closely matches the GRT data and I settled on 44.8gr today after some more testing at .1gr increments. 2630FPS average at 44.8 and I believe it will be closer to 2650 after I get another 100 rounds through the new barrel. It seems both predict that velocity at around 59,000PSI and I just wanted to double check. Thanks again and good to know about the Winchester brass. I had searched for months for a large supply of new brass before deciding on this chambering and it was all I could source a decent supply of.