Ladder Tests In A Modern 7x57 Action

Discussion in 'Reloading Forum (All Calibers)' started by onelastshot, Aug 3, 2017.

  1. onelastshot

    onelastshot

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    I've been researching loads for modern actions for the 7x57. Most printed data is extremely conservative because of the older 98 actions, they like to keep PSI at 45,000. I've got a No. 1 in 7x57 and decided to try a ladder test using Reloader 17. Reloader 17 runs similar to IMR4350 and the maximum load printed by Speer using 175 grain bullet is 45 grains of IMR4350. I'm using the 168 AccuBond but there was no load data for the 168 grain bullet. One advantage is I was able to take advantage of the actions long throat. The published Maximum OAL is 3.065, I can use a maximum OAL of 3.280 which leaves additional room in the cartridge.

    Started the test off at 44 grains and gradually worked my way up. The difficult part was allowing extra time for the barrel to cool, I'm in Arizona and it's going to be over 100 again today. I started at 7:00am to take advantage of the cool morning. I was also sighting in three other rifles so I switched back and forth between them.

    Long story short I quit at 47.5 grains. This load is accurate in my rifle and I felt like I was reaching the safe maximum for my particular action. There were no signs of high or over pressure, the primer corners were still nicely rounded, not flat and the action opened and closed without incident. I just felt the 2 and a half grains over the printed maximum was enough. I'd brought a few cartridges loaded with 48 grains but something inside me said enough was enough. Later this week after I do some more reloading I'll take my new Magneto Speed Chronograph out and see what velocities I'm running at using 47.5 grains of reloader 17. Based upon review of other weight bullets and loads I should be somewhere between 2,750 and 2,850fps. Quite a difference from the 2,433fps, the stated velocity using 45 grains of IMR4350. Four hundred feet per second makes a considerable distance when calculating a maximum point of impact.
     
    Last edited: Aug 3, 2017
  2. centerlineseal

    centerlineseal

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    Let us know of your progress. I'm still working up a ladder for a 7mm-08, 168 gr Berger VLDs with IMR4350. Gave up on RL15 Maybe I should look at RL17

    So far, at 46.0 gr, no signs of pressure, but found a node at 45.4 I'm chasing.

    I also have a 7x57 in a Ruger 77
     
  3. ireload2

    ireload2

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    Your assumption about conservative data for this cartridge is not always a correct assumption.
    You may be correct if you only use the latest manuals but things have not always been that way.

    I have older Speer manuals that list about same data that you used for a maximum load.
    Take a look at Speer data in manuals 7, 8, 9, and 10.

    In #10 Speer listed a max load of IMR 4350 at 47 grains for the 175 grain bullet for a velocity of 2469 FPS.
    The rifle was a Ruger 77.

    The Ruger #1 is far safer than the run of the mill Mauser type bolt gun since there is almost no path for gas to get to your face. In addition the Ruger #1 receiver and breech block are the "locking lugs" for that action and they are massive compared to any bolt gun. For a long time the hottest factory loads for the .30-06 head size are the .270 Win, 6mm Rem. and .25-06 Rem. The Ruger #1 has been chambered for all of them plus the family of H&H magnum head size rounds.
    Apparently factory ammo for the .25-06 and the 6mm is really high pressure because I have found blown factory primers in once fired brass bought at indoor ranges.

    There was a magazine article in either the Rifle Magazine or Handloader Magazine about 35 or 40 years that talked about super velocities/loads in the Ruger 77 in 7X57. That rifle delivered very high velocities at very high charges.
    The author commented that he did a low temp cast of the bore and throat. The rifle had a long throat and it had a groove diameter of about .287. So you might check your groove diameter to see if it is close to nominal or if it is oversize. If you have a long throat and an oversize bore you may find that loading manual is no where close to the maximum your rifle will handle before primer pockets get loose. I would comment that in my own experience with Ruger rifles they have generous chambers. In some cases you cannot neck size a case fired in the Rugers in a Wilson bushing neck die because the chamber is so large at the case head.

    There is also considerable variability in the brass because there are so many companies that make it.
    Over the years I have picked up large batches of 7X57 brass and now find myself with the biggest collection of different brands of any cartridge that I load. They include Norma, WW, FC, RP, Cavim, PPU and Hornady Frontier.
    I found Norma to be a little soft and even found a blown primer in factory once fired brass from an indoor range. The primer pocket didn't just leak, it was at least .010 oversize after firing.

    WW brass may be the lightest and hardest of the brass that I have, so it may handle the hottest loads. RP, Hornady Frontier and FC brass behave like any normal factory brass. The Hornady brass looked a LOT like WW brass including the font used on the headstamp.
     
  4. Zero333

    Zero333

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    Quickload predicts 2,660 fps with at 3.250" coal and 2,700 fps at 3.150" coal. 47.5 gr IMR-4350, 168 Accubond, 24" bbl.
     
  5. onelastshot

    onelastshot

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    I've got an assortment of brass for the 7x57 as well. The thing I've got to do is make certain that I keep my Ruger separate from my Mauser loads; I've got three 98 7x57 Mausers as well.
     
  6. onelastshot

    onelastshot

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    I'll let you know what I get with my chronograph for the 47.5 load of Reloader 17. I'll give it a few days though to let my shoulder mend after firing over a 100 rounds of assorted cartridges today.
     
  7. Zero333

    Zero333

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    I messed up... had I brain block and ran the #'s for IMR-4350. I'll re-post with QL predictions for RL-17 and we'll see how close it is to your actual chrono velocity.

    47.5 gr RL-17, 3.250" coal, 24" bbl, 168 AB-LR, 2,734 fps
    3.150" coal = 2,772 fps.
     
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  8. KMart

    KMart Gold $$ Contributor

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    Your LARGE ring 98 Mausers should handle the higher pressure loads pretty well. A lot of good magnum rifles have been built on them.
    The reloading manuals generally stop their testing around 45,000psi, for the 7x57, because the small ring, mod 93 and 95 Mausers was rated for that pressure.
     
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  9. onelastshot

    onelastshot

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    I just wish that the manuals would explicitly exclude these firearms and provide accurate loads for the more modern actions.
     
  10. Barlow

    Barlow

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    Here is load data from Bob Hagel's book, "Game Loads & Practical Ballistics" for 7x57, Ruger 77 22" barrel.
    175gr Speer SP N205 52gr = 2695, H4831 53gr =2599, H450 53gr =2673, 4350 49gr =2572

    160gr Nosler Pt, N205 54gr =2832, 4350 52gr =2816, N204 52gr =2814

    150gr Nosler Pt, N205 55gr =2910, H450 55gr =2864, N204 54gr =2939, 4350 53gr =2880.

    139 Hornady, N205 57gr =3014, N204 55gr =2981, 4350 53gr = 2904.
    I used the 52gr 4350 and 160gr Hawk bullets to kill a big Montana bull in 1995, and it did get 2800+ MV. I was hard on brass but I never had any problems with the load. Just like any load work up carefully in your rifle, if you get high pressure signs, back off. It's not Ruger #1 data. Barlow
     
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  11. Barlow

    Barlow

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    These loads are maximum! Barlow
     
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  12. Laurie

    Laurie

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    Very interesting Barlow for Bob Hagel's data. I'm currently playing with a couple of Chilean Mausers, a DWM M1895 and Steyr M1912 ('98 type action) plus a mid 1950s BSA Hunter sporting rifle with a very nice Mauser '98 system action, not a copy rather BSA's own development of the Mauser 98 concept. The two military jobs are 29-inch barrel infantry rifles, the sporter a cut-down 21-inch.

    Freebore is massive on all three (as usual in 7X57) so most bullets cannot be put close to the lands within COALs determined by magazine box size with the exception of 168gn and above HPBT match type bullets in the BSA which needs single-loading for them.

    Not that I want to exceed (or even use) 45,000 psi in the M1895, but may go up to just short of 50,000 psi estimated in the M1912 and BSA using QuickLOAD allied to actual MVs. So far, actuals run at around 100 fps down on QL calculations in all three, no doubt due to freebore plus throat wear issues in this elderly trio. The South Americans started out with the old low pressure 173gn RNFMJ load (2,298 fps nominal from 29-inch barrel) in their later '98 action models, but later adopted a high-pressure 139gn FMJ load at around 2,900 fps in long rifles. My M1912 obviously used this one as the tangent rearsight bed has been remachined to a flatter profile and has to be set at 500 or 600 metres before the sight actually starts to rise.

    On manuals, Lyman quotes two sets of loads, but doesn't explicitly show which is which taking me a little while to figure this out. They use an M1895 military rifle with 29-inch barrel, no pressures shown in the tables; a universal receiver and 24-inch test barrel for the SAAMI 46,000 CUP Maximum with pressures shown - and mix them all up. From the M95 MVs, these loads also seem to be somewhere around SAAMI levels and exceed original military loadings. 7X57 is still quite popular in the UK with deerhunters (deerstalkers we call them), but looking at the loads quoted on our 'Stalking Directory' Forum, I suspect many are loading to barely above 40,000 psi in modern rifles - but they still kill deer very well it seems.

    I've always thought that 7X57 in AI form might make an interesting competition cartridge. I know one person who did shoot F-Class with the 7X57AI using RWS brass and he did well until the rifle needed rebarrelling, never doing as well again after that. 55,000 + psi loads, even maybe 60,000 psi, should be quite safe in such an outfit.
     
  13. Barlow

    Barlow

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    Laurie, If I were younger I would rebarrel my Ruger to 7x57AI, just for the hell of it. But I can honestly tell you it has killed everything I ever shot with it. Paul Mauser knew something about efficient cartridge design, because it has stood the ultimate test, the test of time. Barlow
     
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  14. Laurie

    Laurie

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    I've never used the cartridge on game, but it's always been one of my favourites going back to my early centrefire range shooting days when I shot Historic Military Rifle. I had a Boer War souvenir OVS (Orange Free State) M1895 long rifle made by DWM in Berlin and boy, it was a shooter!

    This current trio is an old age nostalgia kick - cheaper and safer than a motorcycle (which the wife wouldn't let me have anyway) even though I struggle to use the iron sights on the military pair. In 20 round comps, I start shooting misses after shot 15 or so when my eyes and arms get tired. Even the BSA sporter which has a 1960s Pecar 4-10X45 scope on it is hard work compared to a modern F-Class rifle and optics.

    I have a friend who owns one of the UK's largest gunshops (but small by US standards) and is a wealthy man with access to any rifle he might take a fancy to. He has used a 7X57 Ruger No.1 in all the time I've known him (around 30 years) and has taken all sorts of game with it including a large black bear in Canada.
     
    Last edited: Oct 23, 2017
  15. normmatzen

    normmatzen

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    I have a 7X57 hunting rifle I built around a VZ-24 action and a WWII 7X57 large ring barrel. I shoot both 162 gr A-MAX and 140 gr TTSX. Both shoot 1 MOA or less and the 162gr.
    I load by the European CIP limits which allows ~52,000 psi for the 7X57 case. I load the 140 gr TTSX TO 2880 FPS AND THE 162G a-max TO 2700 FPS. lOA IS 3.1 " AND 162 a-max IS 3.15'.
     
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  16. Barlow

    Barlow

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    I could never get my Ruger to shoot anything lighter than 154 gr Hornadys. It shoots the heavy bullets much better. I finally gave up as I had 6.5x55's to shoot 120 and 140's in, and that is another killer. Barlow
     
  17. ImBIllT

    ImBIllT

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    2.5gr more powder will probably not yeild a 400fps gain. Also, a 7-08 and 7x57 have almost identical water capacities. The 7x57 has significantly more body taper and a longer neck. I would suggest that starting with a 7-08 starting load, and working up to a 7-08 max load is probably the best way to get up to date data for "modern" actions.

    Going to an AI does give a boost in case capacity over the 7-08AI.
     
  18. Gerard

    Gerard

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    I found this thread because I did a search on Ruger #1 in 7x57. It is old but the information is still relevant.

    Many people lose from sight that the European 7 mm cartridges are different from the American ones. The differences are:

    7x57 and 7x64 Brenneke etc. = .285" groove and .275" bore.
    7mm Rem Mag, 7mm Weatherby, 7-08, 7.21 Firebird and all .280" and .284" cartridges etc. = .284" groove and .277" bore.

    When a .284" barrel is used to build a 7x57, the cartridge neck area is oversize compared to groove diameter. It is best to use a .285" barrel and bullets.
     
  19. DRB51

    DRB51

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    Older topic, but I wanted to chime in re the large ring 98 safety vs the small ring 95s, 93s, etc in 7x57. I'm not sure who in the States came up with the statement of "hold pressures to 45,000 PSI or below for Mauser rifles of 93 or 95 vintage as they're not as strong as the large ring 98s"; might have been SAAMI or a publisher of reloading data, or it might have been a well intended gun writer, but its wrong. As long as your 93 or 95 is an original in 7x57, and hasn't been damaged, it was originally designed for and intended to use standard pressure 7x57 military ammo as manufactured by DWM/Oberndorf or in-country arsenals. CIP standards rate the case for up to 56,564 PSI, and proof has to be 125% of that limit. CIP is much older than SAAMI, who wasn't around when the 7x57 as invented or adopted by Spain, then others. The original military loads for those "weak" 93s and 95s ran at 50,370 psi, which are quite a bit above the current SAAMI limits. I'm not aware of anyone official in Europe telling folks over there to load below those pressures for these older rifles.

    There is a lot of confusion about Mauser models and their relative strengths. Partially because they've been made all over the world by many different countries and arsenals, during peacetime and during wartime. Quality varies, but if originally chambered to 7x57 and not damaged, that 93 or 95 should be fine with ammo at the 50,370 PSI level. The strength of the 93 and 95 is generally considered less than that of the large ring 98 because the 98 is larger. Thicker means stronger, right? Nope - depends on alloys and heat treat. The real reason the 98 is considered "stronger" is the 3rd lug that was added to the bolt, known as the safety lug, and which was designed to keep the bolt in the action if the first two lugs (locking) fail. So the 98 is considered safer, but not necessarily stronger than the 93 and 95, which lack this additional lug. Many of Germany's infantry rifles in WW I were small ring - the 98a. It was chambered for the standard 7.92 S cartridge.

    Elmer Keith once noted that a lot of the bashing of German guns and Spanish guns in the firearms press got started after WWI for German guns, and after the Spanish-American War for the Spanish guns. A lot of that bashing and a lot of the well intended caution has gradually grown from opinion, to myth, to supposed fact.

    There is a lot of great info on Mausers on the internet, so do some searching before forming the opinion about someone else's rifle. A strongly held opinion is not always the same as a well informed opinion.

    There are so darn many Mausers of different action dimensions out there, it pays to be prudent and have a good gunsmith take a look at your 7x57 if you have any concerns about it. BTW, German Mausers were differentially hardened, only in the places it was needed, and a standard strength test to determine where it is on the Rockwell scale can't be done inside the locking lug recesses. Doing it on the actions front lug doesn't tell you squat about the actions safety, but does give you a Rockwell number for that front recoil lug.

    All the best - Dave
     
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  20. Laurie

    Laurie

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    Also, improved gas venting should things go bad and the 98 gaining a gas shield on the bolt shroud to protect the shooter's eyes in event of a catastrophic primer failure or lower case-body split. Remember, Paul Mauser himself lost an eye from this cause when testing an experimental rifle. I can't remember now which of the great post-war gun writers / handloading pioneers it was - George C Nonte Jr, Julian Hatcher etc, - but remember one saying that when you read the early 20th literature on rifle shooting, both military and hunting, it was stuffed full of references to case and primer failures causing frequently serious injury. This was much more common than rifle action failures.
     
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