7x57 AI load data

[rflshtr]

Just joined this forum and am looking for advice on developing loads for a 7x57 AI using a Win Classic Model 70 LA and a re-chambered 7mm-08 22" barrel. I have several AI cartridges but am new to this one and not finding much published load data. My barrel was throated long to handle the 160-175 grain bullets and has been very accurate in fire-forming cases so far. Guidance appreciated.

 

[alientrainwreck]

For my AI Guns I start loadind at the max listed in my loading manual then go up. 7×57AI is one of the best calibers to akleyImprove. I whould add 10% to the max listed in a manaul should give you a good load,with a little room to grow. If I remember correct you will gain 14% over max when akley Improving the 7×57 cartridge. Im not near my Reloading stuff now but I may can find some data that im pretty sure I have cause im a AI fan too I'll post them soon.

 

[rflshtr]

Thanks. I have been starting at max loads for 7x57 and working up and have gotten to between 8% and 10% above with no pressure signs so far. Was hoping for some shortcut ideas but will just keep on doing on what I have been doing until pressure signs show up or an accuracy node is reached.

As a generalization, if a powder works well in the parent, will it likely work in the AI case?

 

[Don McDowell]

You'll want the slowest powders for the parent to make the AI work the best. Watch the chronograph, when you hit 150-250 fps above parent, you're maxed out.
Without pressure testing equipment you have no real idea what pressures you're operating at.
Usually 2% more powder over max is the stopping point.

 

[41 Mag]

You'll want the slowest powders for the parent to make the AI work the best. Watch the chronograph, when you hit 150-250 fps above parent, you're maxed out.

Without pressure testing equipment you have no real idea what pressures you're operating at.

Usually 2% more powder over max is the stopping point.

I agree for the most part with the above posted by Mr. McDowell.

As for the powder though I might not go to the slowest, but I would sure go slower. Like if your already using H4350, you might drop down to something like H4831, but maybe not H1000.

The second part about pressure I wholeheartedly agree with. With the AI cases the straightened out sides will hold the cases in place and not give you as accurate a reading as you might get from one which still had the tapered body, and moves some. The best route to go is like mentioned to watch your velocity and give yourself 150-200fps above what your getting with standard ammo.

That said barrel length will also play into this as well, where as your 22" barrel would be a bit faster if it were say 26, and in that case you might also benefit FROM using something like H1000 verses H4831. But being you have what you have, I would stick to the above paragraph and go with the velocity and call it good.

I built my 25-06 AI using a 28" barrel. I did so to wring out about all I could from the case capacity and using the slowest powder that would give me decent velocity and good groups. I built it expressly to shoot heavy for caliber standard and custom made bullets in the 120 and 130gr range, which it does very nicely. With the standard loads I use in my regular 25-06 I am getting around 3200fps with the 115gr Partition. With the 120's in the AI version I am getting 3250 with what I am calling my MAX load. While this might not seem like much of an improvement over what I had, in the standard version I NEVER broke 3000fps with 120's without ironing out primers, and the 130's never got above 2875 before seeing the same thing. With the longer barrel I can run both the 120 and the 130's up into the 3200fps range and still get quarter sized groups at 300yds. This was my goal, and anything I might be able to go above and beyond is simply not important to me.

 

[ironworkerwill]

A guy I shoot with has experimented with H1000, was never happy with it in 7x57AI. Had moderate success with it in 6.5 Swede. However, I don't think be ever shot anything above 170gr rn.

Personally I'd go with one of the 4350's or RL19 and maybe slow down from there.

Stay away from RL17 unless you already have plenty on hand.

 

[rflshtr]

Thanks for the replies and ideas. Using the latest Nosler manual as a guide, 200 fps over standard 7x57 would put the velocity at or above .280 Rem and about 100 fps less than .280 AI. Is that realistic to expect for a long throated 7x57 AI? I will chronograph but just trying to get some idea of realistic expectations.

 

[Don McDowell]

150-200 fps has been the realistic expectation of the AI's for the last half century or so. Sometimes a cartridge will make that, other times not so much.

 

[alientrainwreck]

I now not many people like Hodgdons Superformance but it brought my 30-06AI to life.