Home Forums Reloading Big Game Rifles Powders for 7x57 Mauser

Flintlocke, I get your point. Problem is the military standard for accuracy from the average rifles isn't looking for sub-moa grouping, just minute of man type accuracy.
Paul B.

Well, miracles of miracle I actually made it to the range this morning. Left the house at 0615 and reached the range at 0645. Temp according the thermometer in my truck said 68*. Wind was forecast to be calm and was blowing about 6 to 12 MPH quartering the range from the southwest.

The rifle was the custom Mauser in 7x57 as mentioned earlier and the load was 45.5 gr. Re17, Remington brass, CCI 200 primer and the 150 gr. ABLR. I shot three shot groups. All powder charges hand weighed.

Load #1. two shots 15/16" No third shot. Dud primer failed to ignite the powder I've been getting quite a few misfired from those primers.

Load #2. 2 1/8" x 1" Best group of the test series.

Load #3. 2 3/8" x 1 3/8" Group was vertical in nature with the 2 3/8" the height.

Load #4. 2 1/16" x 1 3/8". Load #5 1 3/4" x 2 3/8". Not quite a perfect triangle.

This rifle is an enigma. Not only is accuracy eccentric, but loads will extract nice and easy one time that hard to open the action the next and this even with a known mild load. Here's where it gets even more weird. Case head expansion and pressure ring expanse are perfectly normal. Primer pocket after and average six loadings of hotter than normal loads from slightly over max to possibly close to absolute maximum for that particular rifle are still tight in that batch of brass. I've run those same loads in my M70 FWT and more reaching a very accurate load with the Nosler Partition and running 2900 FPS+. I also reached that 2900 FPS with the ABLR but with dismal or should I just say lousy accuracy. (with the ABLR)

I'm a bit on the stubborn side. I once bought a Ruger M77 RSI (The one with the Mannlicher style stock) on the cheap because it's original owner could not get it to shoot a group with anything he tried. It took me a little over two years to find a load that would give reasonably accuracy for hunting. I figured if I could get a consistent load that would do 1.5" at 100 yards then I'd call it good. Well it took a stiff charge of W760 and the Speer 165 gr. Hot Core. Velocity is only 2550 from the stubby 18.5" barrel but I've taken deer from 35 feet to 250 yards with it. Try any other 165 gr. bullet and forget about it. That's the only combo that will work in that rifle. My point being, I'll get that Mauser to shooting right. May not be tomorrow or next week but I'll figure it out hopefully before I turn toes up.
Paul B.

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

Just my opinion but I think Re19 just might be a bit too slow for a 140 gr. bullet in a 7x57. However I have gotten some interesting results using Re17 in that cartridge. One load with Re17 and the 150 gr. Nosler Partition does 2847 FPS. Primers look reasonable that the cases have been loaded 5 or 6 times and primer pockets are still reasonably tight. With that said though, I've dropped the load back enough for a velocity of 2710 FPS with only a slight loss in accuracy. Rifle is a Winchester M70 Featherweight. That top load also shot well in a Ruger #A in 7x57 but even the 2710 FPS load locks up the bolt on a custom Mauser I have. I have absolutely no idea why but it shows high pressures long before the other two rifles. Damn thing is driving me sane.
Right now I'm trying to get the Nosler ABLR 150 gr. bullet to give some modicum of accuracy but it hasn't worked in any of my 7x57s and not in my .280 Remington as well. Probably be a few days before I can get to the range. We've had a few heavy rain showers the past few days and the range is usually a mud hole.
I did a bit of work with the 160 gr. Speer Hot Core but it and Re17 apparently don't agree with each other. I'll probably run a series with H4350 when I get done with the ABLRs.
Paul B.

Tighter, shorter throat?

PJGunner, your comment about RL19 and 140g bullets is not something that had occurred to me before, but I think you are right on in your assessment that RL19 is too slow for optimal performance with 140g. bullets. I have never gotten desired velocities with RL19 and 140g bullets in any 7x57 Mauser or 7x57AI I've owned.

Note: I too have had difficulties obtaining MOA or better groups with Accubonds, in every caliber and every rifle I've fired them in. I've done so only with difficulty. Oddly, I've routinely shot far better groups with Partitions and Ballistic Tips, so that's what I use in Nosler bullets these days.

Regards,

Renaissance

No, it has the standard long throat common to the 7x57. One thing I have notices is it has the tightest chamber of any rifle I own. You know how when you look at a fired case how there is usually a slight bulge to one side near the hear of the case? Well the bulge from ammo shot in that rifle literally has no bulge. It's there but most of the time it takes a micrometer to find it. Only the really hot load show it enough to be easily visible.
Paul B.

I've found that in my rifle H4350 is as good as it gets. RL19 was too slow, and even with 4831sc and 50.6gn in the case behind a 160gn Protected Point Woodleigh bullet, it didn't shoot as well as H4350 did. at the moment I'm pretty happy with Norma Brass, CCI LR primers, 50gn H4350 and a 139gn Hornady SST doing 2,800 at the muzzle. 154gn Hornady Interlocks aren't too shabby either. It was mentioned somewhere here that you should try for a reasonable muzzle velocity, and work your load development around that, not a bad idea as long as accuracy is not compromised.

Paul I seem to recall that the Mauser custom rifle has a shorter throat than your other sevens, if that's correct, your problem may be due to the short throat not in agreement with those heavier bullets. How does it handle the 100grainers?

My Mauser custom has the standard long throat common to military barrels as this was one of my specifications when I had the rifle build done. Twist is also the standard as originally used in the 7x57 rifles. Lightest bullets I used in that rifle are the Barnes 140 gr. TSX which it definitely does not like. Federal 175 gr. factory shoot reasonably well and Winchester 145 gr. factory ammo are decently accurate but I'm looking for the potential the cartridge has, not the underloaded factory levels. I get great velocity and accuracy from a Ruger #1A with 22"barrel and even better velocity from a Winchester M70 XTR Featherweight with 22" barrel. The Mauser has a 23" barrel.
Paul B.

RL19 has worked very well for me in the 7X57.

The best powders for 3 of the 7x57s that I have had was always 4320 ,4895 , or 4064. I did not try to push them to max and tihs powder was always with 139, 140, 150, and 154 grain

bullets.

I have had good results with Woodleigh 160 grain pp bullets ahead of IMR 4451 or H4350 in my 2014 M70 featherweight. Cases and primers are both by Remington. I will not state what the powder charges were (as they are "over book"), but I followed MD's recommendations as published here on the "Fire and in his magazine articles. They work! A chronograph is a great help in load development. No over pressure signs noted.

My seven also likes the 160gn Woodleighs but not using H4831sc. I've found that H4350 works best on all bullet weights from 140 to 160 and that's about the only weights I shoot now. Although I did give the Hornady Interlock 154gn a run, and they did Ok. I only shoot 3 round groups in my hunting rifles, because A) the barrel gets too hot, and B) if you haven't killed it in 3 shots maybe hunting is not for you.

Powder temperature sensitivity better known as ( hunters excuse for missing) LOL

I currently have some Norma brass which I only use with the Hornady 139 and154 grin bullets. I also have some Selleir & Bellott brass, which is purely for the Woodleigh bullets. The S&B brass is 2 grains heavier than the Norma, so I've worked my loads up accordingly. As I've said before H4350 is the only powder I'll use. I'd like to try R17 but supply is a bit erratic down under, and I have heaps of H4350. I'm playing with the Woodleigh bullets mainly because their 140gn 7mm bullet is very well constructed and will give better penetration on larger deer like Reds and Sambah. For the most part I'll stick with the 139gn Hornady SST. I'm getting 2,800fps with them, and the deer and pigs I've hit with them have never complained.