Home Forums Reloading Big Game Rifles Powders for 7x57 Mauser

Howdy, All,

I started experimenting with the 7x57 Mauser (and from there the 7x57 Mauser Ackley Improved) about twelve years ago. My current 7x57 Mauser is a Model 70 Featherweight with a 22" barrel, a rifle which has received various tweaks and tinkerings over the years from a variety of gunsmiths. The rifle, still with its original stock, is glass- and pillar-bedded with a Timney trigger. With proper handloads, and if I do my job properly, this rifle is a sub-MOA shooter.

The 7x57 I had for several years before the Model 70 was built on a Mauser 98 action made in Czechoslovakia circa 1936 or so and fitted with a 24" Douglas barrel and Hogue stock. That rifle is now a 7x57 AI rifle with a new 24" Douglas barrel. It took several years (and two barrels, one in 280 Remington) before I managed to get the rifle to shoot straight. A friend of mine who is mechanically inclined deduced that the box-style magazine in the M98 is vunerable to lateral and frontal torsions if it is not fitted perfectly to a given stock. The torsions, which can be difficult to detect, were what caused the M98 to shoot everywhere except at a bullseye. Once we figured that out, we modified the Hogue stock and rebedded the action into the stock. With careful handload development, I have since shot some of the best groups I've ever produced with any high-powered centerfire rifle. It now routinely produces MOA or better groups with the right loads.

I also have two other 7x57 AI rifles, one built on a left-handed Remington 700 action with a 25" McGowen barrel and an HS-Precision stock, the other a Remington 700 right-handed action with a heavy (as in too heavy, which is my fault; it was my first custom rifle) Shilen 24" barrel, also in an HS-Precision stock. Both rifles are extremely accurate.

Loads that Work for My Model 70 Featherweight in 7x57 Mauser (all muzzle velocities are the average velocity of a five- or ten-shot group):

120 grain Barnes TTSX, 3.025" OAL, starting at 51g. of H-414 and chronographed 15' from the muzzle: 3041 FPS.

Slowly increased the load to 53g. of H-414 and 3144 FPS.

Note: I did incrementally increase the load to 54g of H-414 and 3218 FPS, but felt the pressures were becoming a concern, especially in the intense heat and sun of NE TX. H-414 powder is temperature sensitive. I discovered this with cartridges left out in the sun on a summer day.

120g. Nosler BT, 52g. RL 17, 3100 FPS.

120g. Nosler BT, 53.5g. H-4350, 3150 FPS.

120g. TTSX, 51.5g. RL17, 3100 FPS.

120g. TTSX, 54.5g. H-4350, 3165 FPS.

130g. Sierra Match King, 51g. H-414, 3030 FPS. Note: An accurate load.

139g. Hornady SST, 50.1g. H-4350, 2850 FPS.

139g. Hornady SST, 50.5g. H-4350, 2904 FPS. Note: This load, which is an MOA load, is as warm as I care to go. My field notes from eight years ago, which were usually derived the hard way, state: "Do not exceed 51g. of H-4350 with 139-140g. bullets."

140g. Nosler Partition, 50.2g., H-4350, 2845 FPS. This is an MOA or better load which appears to be safe in all temperature conditions. I did experiment with slightly increased powder loads--up to 51g. of H-4350 and 2920 FPS muzzle velocity--but observed primers beginning to look flat and the bolt developing slight resistance, so I backed the load down, incrementally, to 50.2g., which is accurate and has never given my rifle any problems.

Note: I have attempted load development with the both the 139g. Hornady SST and the 140g. Nosler Partition and RL 19 powder. I could not get satisfactory velocities (e.g., around 2850 FPS or higher) with either bullet without pouring so much powder in the case that it filled completely to the top of the neck. I compressed it, added more powder to the case, and compressed it again before finally seating a bullet. At this point, with up to 51.6g. of powder stuffed into the case, I developed a concern of future bad things at the shooting bench, so I discontinued using RL 19. (I am aware Nosler reloading manuals from the past decade list up to 51.5g of RL19 for 140g. Partitions or Accubonds, but at well over 100% compression rates. Why bother?) H-4350 is a fine powder for the 7x57 Mauser with appropriate bullet weights, as is H-414.

I have used all of the above loads (except the Sierra Match King) on wild hogs ranging from 75 lbs. to 300+ lbs, at distances of 25 yards to 250 yards or slightly farther. When I made a proper shot, I could not detect any difference in the stopping power of any of the loads. Wild hogs are incredibly tough. I have made numerous heart-lung shots at 25-50 yards with the TTSX and NBT loads, field-dressed the hogs and found nothing but mush where the heart-lungs used to be, yet the hogs always ran 30-50 yards anyway, which is impossible, but there it is. The only times I've seen instant kills on any of the hogs I've taken were with head shots, and I won't take a head shot unless I am 100% positive of my load, my rifle, the shot picture, the distance and myself on a given day. The vast majority of my shooting is done at the bench, with paper targets and often a chronograph at hand.

Regards,

Renaissance