257 Roberts Ackley Improved

gunner72

gunner72

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hello, I'm new to this forum and I hope someone might be able to give me some info on said caliber. I got a bit of info and some recipes that i am going to start with but would love some sugestions on powder, bullet types and weight that maybe some of you guys that are more familiar with this cartrige can offer. Hope someone can give me a hand.
Thanks
 
I'm looking forward to seeing what comes about on this post as I have a barrel ordered in the same caliber and there doesn't seem to be too many people who shoot this round. On paper it looks impressive, but it sure isn't popular.
 
Nosler has some info on 100gr's witch is what i plan on shooting and the best reloading data book that i have for the 257 AI is the new seirra book. They have loads for 75gr HP? I emailed berger and never got any info on 100s but they did have some on 115gr. The Barns book #3 has a load for 75's in a solid point. I've just been snooping around on the net and emailing who ever i can. I feel your pain man. lol. I guess picking a cal like this I knew there would be alot of trial and hopefully not too much error.
 
The Hornady Handbook 3rd Edition has several pages of load data for the .257 Roberts Improved but their's is the RCBS version (28 degree shoulder rather than 40 degree shoulder).

100 gr Spire Point - 38.2 grs IMR 3031, 40.7 grs H4895, 41.1 grs IMR 4064, 41.9 grs IMR 4320, 42.7 grs H380, 45.3 grs IMR 4350, 50.5 grs N204, 51.1 grs W 760, 50.0 grs H4831.
These are all MAX loads.

The N204 and W760 are the fastest = 3200 fps.

Do you need other bullet weights?

The Handloader's Manual of Cartridge Conversions has the Ackley version but only gives 1 load - 50.5 grs N204 for 3200 fps.
 
chopices

Reloder 19 and 22 can be real good in an AI. I am shooting 110gr Accubonds that group very well. My rifle is a Win XTR Featherweight in a laminate stock. FS
 
Kevan said:
I'll have to check my load book, but I think my 75gr. V-max load uses about 50 gr. W760. Not certain of velocity, but it really wacks coyotes...
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Sweet.:D I know this is a hard question but, what kind of effective range can you get with this? Sometimes those coyotes hang up quite a ways away.
 
KDX said:
Sweet.:D I know this is a hard question but, what kind of effective range can you get with this? Sometimes those coyotes hang up quite a ways away.
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I like to keep my shots within 300 yds. because I'm getting old and feeble.
My current 257 AI is sighted in about +2" @ 100 yds and wears a 2 3/4 X 10 Weatherby scope with a fine crosshair.
That sight-in takes the guesswork out of making a 300 yd. shot and a 100 gr. Speer stays on the same vertical line and lands about 1/4" lower @ 100 yds.
My third and current 257 AI is on a custom '03-A3 Springfield acquired in a swap with a fellow CGNer.
Its a bit heavy for field carry but at the same time makes a really stable platform and really reaches out.
 
Thanks for the info Kevan. What is your particular bullet/powder combo for deer? I won't be using anything heavier than a 100gr bullet with the barrel I have ordered (as per their recommendation).
 
KDX said:
Thanks for the info Kevan. What is your particular bullet/powder combo for deer? I won't be using anything heavier than a 100gr bullet with the barrel I have ordered (as per their recommendation).
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My current 257 AI came into my hands after deer season, but in a previous rifle my deer load was a 115 NP over 53.0 RL19.
Never chronographed it but it grouped about an inch, was fast, and took several deer. As I recall case life was very good with that load, but work up to it all the same.
 
I was just at the Consort gun show and I found a box of 257 Roberts 117 hornady ammo. Should a guy be worried at all about shooting them in my AI. I got bs'in with one of the guys that had a table set up there about fire forming brass and he told me to be careful with the full load of powder. I have done a fair bit of reading on fire forming but I've never done it myself.
 
I have only had experience with rimmed improved cases (.218 Bee, .30-30. .303). With a rimless case like the .257 you might have a headspace problem if you fire factory loads in an improved chamber and may experience a case separation.
It would probably be safer to pull the bullets, dump the powder and go through the process of fireforming with a light charge of pistol/shotgun powder.
 
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Just an update. Finally got my dies and brass and I found a box of Hornady loaded ammo at the Consort gun show. I decided to use 32gr IMR 4895 and some advice i got from an old gunsmith I know. I put a 117gr round nose on top of it and seated them right to the lands. I could tell by sharpness of the shoulders with the factory ammo that there was a bit more preasure in the factoy loads. The primers were also sticking out a little! I don't know if this is from over preasure or just headspacing with the wrong shoulders? It seems to shoot the reloads that I am forming very strait. I shot them all threw the chrony and the reloads were around 2250 and the book says 2400. Must be loosing that in the brass exspantion? The factory Hornady's were between 2620 and 2551. Also 117gr. The 257 AI rounds that I loaded are 100gr Sierra SBT with 43.5gr of IMR 4895. Suppose to be around 3200fps witch would be great. That would put them at the same speed as my .243, .270, and .300wm at the muzzle.I also reloaded a handfull of 87gr bugers that are suppose to do 3400fps and some 100gr Nosler BTBT that are suppose to be around that 3200 mark. Now that i have these brass formed should i still be useing the full length die? Let me know if you have any ideas. This image has been resized. Click this bar to view the full image. The original image is sized 764x1023 and weights 167KB.
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Well i dug out P. O. Ackley`s books for the original data. He only lists one powder load with each bullet. 100gr bullet .44gr.-4064=3088fps. 43gr.-3031=3165. 46gr.-4064=3165. 50gr.-4350=3257. 47gr.-4320=3322. 42gr.-H380=2862. 117gr bullet 49gr.-4350=3120.40gr.-H380=2570. Like most of hie loads no mention of rifle, and this data is very out of date. He considered this a very good cartridge.
 
Most loading manuals have recipes for the improved version of the 257. I use the Sierra 117 gr boattails for deer and antelope and the old Speer 87 gr hollowpoints for all varmints using the loads in the Sierra and Speer manuals and get great performance from my 257 AI. Some of the earlier editions of loading manuals have different recipes and those manuals can usually be had at a reasonable price at any decent sized gun show.
 
257 ai

Stick with the slower powders in this cartridge configuration. Pressures tend to spike very quickly. I use H4831 as the fastest powder in mine.

One other thing to take into consideration, there are lots of different ideas on what makes a 257AI. I'm sure you probably know your case and chamber so all should be well.

I know of 5 other 257AI chambered rifles, besides my own and all of the chambers are slightly to grossly different. Mine is to PO Ackley's specs. A lot of smiths made up their own versions and called them 257AI.

A very nice cartridge but don't expect any screaming performances over the parent case.

Most 257AI rifles today are built on modern actions and can be loaded to higher pressures than Ackley's originals. Still be careful, it doesn't take much of a powder or bullet change to put pressures in an uncomfortable range.
 
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