Load data for 7 x 57 Improved?

Doug

Doug

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OK, so I had extrapolated some 7 x 57 data for my Ruger 77 in the 7 x 57 Improved (40 degree shoulder). I am clearly not a ballistician, since I ended up with a bunch of split necks.

I have quite a range of powders and quite a range of jacketed bullets, so any TESTED recipes would be welcome. If you are willing to provide them but don't wish to publish them here, please send me a pm.

Many thanks!

Doug
 
You may not have over pressure loads, or they may be too hot, but the necks won't tell you either way. Split necks are because your brass is work hardened, not a high pressure load. Anneal the necks and splits will go away.
I used to have a 7x57R improved, but do not have the data any more. MY loads were developed by using regular data and carefully working up about 5% higher powder wt than regular "book max". A chronograph is very useful tool when in doubt.
 
Doug, you've been in this game long enough to know that most people will not give you a load if they don't know what rifle you are loading for. Is this rifle a Remington/Ruger/Winchester/Mauser 98/Tikka etc???? Hopefully it isn't one of the older M93/95 actions.

I have a Remington 700 that started life as a 7x57. It had some damage to the chamber on the shoulder so after doing a chamber cast it was pretty obvious the it could be cleaned by opening it up to the Improved with a 40 degree shoulder and a 2 degree taper to the case. The shoulder was also pushed out so the neck was on one caliber long. This really souped up the cartridge. Base to start of shoulder measured out to 1.785 in. Shoulder diameter is .460 in OD and OAL case length turned out to be 2.235in after fire forming.

After doing some volumetric testing we found it to be very close to the 284 Win. So that is where we started. Velocities were best using IMR 4350 and out of a 22in bbl that rifle will give an honest 2900fps with 140 grn bullets without pressure signs.

We used that same reamer in a Ruger No 1 because the fellow that tried my Rem 700 was impressed by its better velocities as well as accuracy. The new chamber didn't make the rifle any more accurate but it definitely increased his velocities.

By the way, we started playing with H4831 and increased the velocities even more. RL19 was about the same and RL22 was to slow. H4831 actually did better in the longer bbl on the Ruger #1. The extra two inches gave another 50fps.

Even though the H4831 gave higher velocities pressure seemed to be lower from the look of the primers.

I don't know if this helps you at all but if that were my rifle, I would start with 284Win start loads and work up from there.
 
Doug - you discovered that there is just nothing out there that's seems trustworthy on Ackleys (same applies for the 30-30 AI so I did my own post). For the record, I have never owned a 7X57 AI, but I have a 7X57 I've shot a lot. Still, I think I have some points to consider that should help, but it starts with some questions:

1. What brass are you using? Their capacities can vary quite a bit. http://www.canadiangunnutz.com/forum/showthread.php/1120440-Some-7X57-Case-Capacities? I use Prvi as it has high capacity and unlike recent Winchester, comes out of the box with tight primer pockets. I couldn't find Prvi 7X57, so I resized some 8X57 I have.

2. How is your gun throated? I can seat the 175 gr Hornady RN out to 3.250". That provides quite a bit extra powder space.

3. Which "Ackley" do you have?


image004.jpg


4. Finally for the finale, what is your usable case capacity in grs of water for fire-formed, but neck-sized brass? Your absolute best case scenario (high capacity brass, "Improved" to the max, and long throated) is going to add about 10% case capacity (6.0 grs) over a "standard" 7X57. You're using a strong action, so you can employ pressures like are published for the 7mm-08 and 280 Rem (Many 7X57 pressures are below 50K psi).

Any way you cut it, as a sanity check, you still (probably) do not have a case capacity equal to the 280 or 284, so you cannot use 280 or 284 loads (although 280 or 284 starting loads could be an upper level sanity check), and you should not expect more than 50-75 fps over an "unimproved" 7X57 in the same conditions (same brass, throat and action).

That's the "official" line, now here's what some experienced guys have done:

bearhunter said:
... I don't know if this helps you at all but if that were my rifle, I would start with 284Win start loads and work up from there.
Click to expand...

Of course what many guys do with their AI, is add powder until they get loose primer pockets in 3-4 firings - that's an option too. That's what I've done with my long-throated 7X57 in a M98 action with high capacity brass, and my max load for the 175 gr Hornady RN is 52.0 grs of H4831, which is a 284 Win starting load, and my chamber is not improved.

In other words, I'm not disagreeing with bearhunter, in fact depending on your usable powder capacity, I'm pretty close to saying: "X2".
 
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bearhunter said:
Doug, you've been in this game long enough to know that most people will not give you a load if they don't know what rifle you are loading for. Is this rifle a Remington/Ruger/Winchester/Mauser 98/Tikka etc???? Hopefully it isn't one of the older M93/95 actions.

I have a Remington 700 that started life as a 7x57. It had some damage to the chamber on the shoulder so after doing a chamber cast it was pretty obvious the it could be cleaned by opening it up to the Improved with a 40 degree shoulder and a 2 degree taper to the case. The shoulder was also pushed out so the neck was on one caliber long. This really souped up the cartridge. Base to start of shoulder measured out to 1.785 in. Shoulder diameter is .460 in OD and OAL case length turned out to be 2.235in after fire forming.

After doing some volumetric testing we found it to be very close to the 284 Win. So that is where we started. Velocities were best using IMR 4350 and out of a 22in bbl that rifle will give an honest 2900fps with 140 grn bullets without pressure signs.

We used that same reamer in a Ruger No 1 because the fellow that tried my Rem 700 was impressed by its better velocities as well as accuracy. The new chamber didn't make the rifle any more accurate but it definitely increased his velocities.

By the way, we started playing with H4831 and increased the velocities even more. RL19 was about the same and RL22 was to slow. H4831 actually did better in the longer bbl on the Ruger #1. The extra two inches gave another 50fps.

Even though the H4831 gave higher velocities pressure seemed to be lower from the look of the primers.

I don't know if this helps you at all but if that were my rifle, I would start with 284Win start loads and work up from there.
Click to expand...

As I stated in the first line, it is a Ruger 77. Thanks for your input.

Doug
 
Andy said:
Doug - you discovered that there is just nothing out there that's seems trustworthy on Ackleys (same applies for the 30-30 AI so I did my own post). For the record, I have never owned a 7X57 AI, but I have a 7X57 I've shot a lot. Still, I think I have some points to consider that should help, but it starts with some questions:

1. What brass are you using? Their capacities can vary quite a bit. http://www.canadiangunnutz.com/forum/showthread.php/1120440-Some-7X57-Case-Capacities? I use Prvi as it has high capacity and unlike recent Winchester, comes out of the box with tight primer pockets. I couldn't find Prvi 7X57, so I resized some 8X57 I have.

2. How is your gun throated? I can seat the 175 gr Hornady RN out to 3.250". That provides quite a bit extra powder space.

3. Which "Ackley" do you have?


image004.jpg


4. Finally for the finale, what is your usable case capacity in grs of water for fire-formed, but neck-sized brass? Your absolute best case scenario (high capacity brass, "Improved" to the max, and long throated) is going to add about 10% case capacity (6.0 grs) over a "standard" 7X57. You're using a strong action, so you can employ pressures like are published for the 7mm-08 and 280 Rem (Many 7X57 pressures are below 50K psi).

Any way you cut it, as a sanity check, you still (probably) do not have a case capacity equal to the 280 or 284, so you cannot use 280 or 284 loads (although 280 or 284 starting loads could be an upper level sanity check), and you should not expect more than 50-75 fps over an "unimproved" 7X57 in the same conditions (same brass, throat and action).

That's the "official" line, now here's what some experienced guys have done:



Of course what many guys do with their AI, is add powder until they get loose primer pockets in 3-4 firings - that's an option too. That's what I've done with my long-throated 7X57 in a M98 action with high capacity brass, and my max load for the 175 gr Hornady RN is 52.0 grs of H4831, which is a 284 Win starting load, and my chamber is not improved.

In other words, I'm not disagreeing with bearhunter, in fact depending on your usable powder capacity, I'm pretty close to saying: "X2".
Click to expand...

Thanks Andy.

Mine is the 40 degree shoulder, as I stated in the first post.

Yes I knew about case capacity, having been warned that Remington brass in particular had diminished case capacity. I was using WW brass. I have not played with OAL yet, but the 160s I had loaded were noticeably "long" and did not touch the lands.

I am not shooting the rifle to make it a hotter 7 mm, for that I have a 7 RUM. I am just trying out another new-to-me cartridge.

Doug
 
Doug said:
Thanks Andy.

Mine is the 40 degree shoulder, as I stated in the first post.

Yes I knew about case capacity, having been warned that Remington brass in particular had diminished case capacity. I was using WW brass. I have not played with OAL yet, but the 160s I had loaded were noticeably "long" and did not touch the lands.

I am not shooting the rifle to make it a hotter 7 mm, for that I have a 7 RUM. I am just trying out another new-to-me cartridge.

Doug
Click to expand...

Doug - it's a 40 degree shoulder, but what's the length of the neck - #2 or #5 above, or just a one diameter (0.284") long neck? It all comes down to usable case capacity and the chamber, brass and throat all play into it.

If you just want to shoot it, there's nothing wrong with standard 7X57 loads, or you could work up to starting 284 loads.
 
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There's data on Reloader's Nest listed as 7 x 57 Ackley. Not a great deal of loads though.
More here from a 10 second net search. Add the W's. .accuratereloading.com/757ackley.html
 
sunray said:
There's data on Reloader's Nest listed as 7 x 57 Ackley. Not a great deal of loads though.
More here from a 10 second net search. Add the W's. .accuratereloading.com/757ackley.html
Click to expand...


Yes I have read all of them, and more thank you. I am looking for persons here who have actual experience with their own loads.

Doug
 
Doug... I had a Ruger No.1-A 7X57 AI 40 degree that was short necked... I throated the gun to take 160 Partitions seated out. I settled on 51.0 grains of N160... but 49.7 grains of RL-19 was a good load also. Neither 760 or RL-22 netted satisfactory results.
 
I see this thread is about a year old. I got intrigued by this calibre last year after burning out a 7RM. I started with a Tikka T3 in a 7-08 and had it rechambered to a 7x57AI, also changing out the bolt stop and mag for the long version. I believe my throat is on the short end. My max COAL doesn't much exceed 3.2" depending on the bullet. I may consider getting the throat reamed to the longer dimension depending on what the gunsmith says. Just thought I'd throw in some of my work. I use Lee Collet dies for all my loading and a crimp die if bullet depth doesn't give good neck tension. So far, my core loads are:

52.0 gr IMR 4350, Fed 210, Dominion Brass, 140 Matrix bullet at about 2900 fps

54.0 gr H4831, Fed 210, Dominion Brass, 160 Speer DeepCore, at about 2800 fps

51.0 gr IMR4350, Fed 210, 139 SST, Dominion Brass, at about 3015 fps (some bolt stiffness on this one - but very accurate, clover leafs!)

Working on:

140 TTSX - looks like 50.0 gr RL17, Fed 210, Dominion Brass, crimped, gives 2900 fps and good groups - need to do more testing to confirm

139 GMX - using RL 19 to work up to 57 gr. Dominion Brass. This is a long bullet and am experiencing compression at 55 gr. Just doing MV and pressure testing at the moment

 
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I am indeed in the Great White North now and aay from my shootin' irons.......

But back to Andy, that rifle went to a new home in one of the recent raids on the gun room.

Doug
 
Ltbull01 said:
I see this thread is about a year old. I got intrigued by this calibre last year after burning out a 7RM. I started with a Tikka T3 in a 7-08 and had it rechambered to a 7x57AI, also changing out the bolt stop and mag for the long version. I believe my throat is on the short end. My max COAL doesn't much exceed 3.2" depending on the bullet. I may consider getting the throat reamed to the longer dimension depending on what the gunsmith says. Just thought I'd throw in some of my work. I use Lee Collet dies for all my loading and a crimp die if bullet depth doesn't give good neck tension. So far, my core loads are:

52.0 gr IMR 4350, Fed 210, Dominion Brass, 140 Matrix bullet at about 2900 fps

54.0 gr H4831, Fed 210, Dominion Brass, 160 Speer DeepCore, at about 2800 fps

51.0 gr IMR4350, Fed 210, 139 SST, Dominion Brass, at about 3015 fps (some bolt stiffness on this one - but very accurate, clover leafs!)

Working on:

140 TTSX - looks like 50.0 gr RL17, Fed 210, Dominion Brass, crimped, gives 2900 fps and good groups - need to do more testing to confirm

139 GMX - using RL 19 to work up to 57 gr. Dominion Brass. This is a long bullet and am experiencing compression at 55 gr. Just doing MV and pressure testing at the moment
Click to expand...


I see you are using Dominion brass. It is pretty soft and you may find you do not get that many firings.....
 
YukonWolf said:
I see you are using Dominion brass. It is pretty soft and you may find you do not get that many firings.....
Click to expand...

I agree, it does appear soft to me. The plus is that I'm only neck sizing and have hardly had to do any trimming at all. That should make it last for a while. I have some Win brass but need more. What brass are you using?
 
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