7x57 AI

[frnkeore]

I have a nice custom Mauser in 7x57 AI. I have Ackey's load data for it but, does anyone have any accurate modern powder loads for it? I have 110, 140 and 160 bullets. I'm going to pick up some Speer 130's also. It's a under rated cartridge and very hard to find loads for. Can anyone help me out?

Frank

 

[Joe O]

As with all Ackley Improved,they shoot a parent factory round,and fireform to the improved chamber.The variable would be a tight neck,ie,chamber neck is smaller or same as factory loaded round,which would require turning the necks before fireforming.If a 7x57 chambers easily,take measurement of the unfired neck.After fireing(measurement will be .001 smaller than the neck chamber).That info will give you the bushing size for desired neck tension.As for loads,PO Ackley always recommended a stout load to fireform for his chambers,so I use close to the max load listed in the loading manual for the parent case.I would then increase one grain to start in the fireformed cases,and gradualy (in that case)go .3 gr at a time,watching for pressure signs.I do use a crono and stop when I achieve the accuracy,not max velocity,although,they are sometimes at the same load level.Need to vary seating depth as well.

 

[bheadboy]

on all my AI chambers, i take a fireformed case and measure the water volume vs the std case capacity. the % increase in volume is then used to slowly increase the max standard case loads up to the % water volume increase,

this has given me a good result every time. watch the presure signs as you go up and i stop when the case pressure ring expands by .001'

Bob

 

[1000yardstare]

P.O. Ackley said the 7x57AI is one of the better improved cartridges. For anyone interested, PT&G will e-mail you a reamer print, Kiff print #20639. Looks like a no-turn neck with a neck resize diameter of 0.307 but you would have to verify this with Kiff.

For some loads with modern powders check out the AmmoGuide web site http://ammoguide.com

 

[tiny68]

load tables

Contact Sierra tech support and request a pdf of their 7x57 AI load table. I know they have one, I have seen a hardcopy of it. They sent me one for the 6 Ackley as a pdf. I think the 7x57 and all its off springs are great cartridges. I have a couple of 6mm Rem and 6mm Rem Ackley. My only issue is that work best with a long action if you want to use heavy bullets and fully utilize case capacity. Luck, Tim

 

[oldroper]

I have a nice custom Mauser in 7x57 AI. I have Ackey's load data for it but, does anyone have any accurate modern powder loads for it? I have 110, 140 and 160 bullets. I'm going to pick up some Speer 130's also. It's a under rated cartridge and very hard to find loads for. Can anyone help me out?

Frank

My first wildcat was a 7x57AI and I got my data from an old Speer wildcat manual #4. If you look at the loads from Ackley manual those are max and best to start 10% below. There also was a comment about the pressure in Speer manual the loads they had was around 60K psi vs SAAMI @ 51K psi so something to watch on older actions.

If you got a good action I start about 1/2gr under max loads from Nolser # 6 manual and chronograph those loads and see how they compare to the data velocity also measure CHE. Well good luck

 

[frnkeore]

Thank you to all that answered my request.

Ammo Guild is a great site, one that I didn't have. I've been a Ackey fan since at least 1970 and have 3 of his books. His loads are the ones that Speer that Speer has in the Wild Cat manual (probaly he barrowed the info from Speer).

I'll contact Sierra tomorrow for there info. My gun is a 98 Mauser so, it's perfect for OAL. The % on increase over std data is a good one, too.

PTG only 5 mi's from me and i just had a neck and throat reamer made in Laupa/Palma configeration to do redo a 300 Savage to 308 lenght and try it on two '06's a 721 and a Mod 54 Win. The 300 is a 722, all with 24" barrels. I know the OAL will be to long for the 06 mags but, I only shot targets.

Again, that you all for your input. This is a great site. I'm new to it, also,

Frank