The real advantage of an Ackley

[C.W. Richter]

let me know if you wish to improve the performance of your 25-06 handloads. IMR 4350 cannot be beat for accuracy in nearly ever iteration of 06 cases-necking up or down, but greater V can be achieved by switching powders/primers. ideally the 25s should have a 26" bbl to begin with. That alone will get you 100+ fps. the .257 AI will drop a deer like a bad habit out to 300 yds (just like a Wby.) After that, it'll take a few steps and fall over (out to 850.) Pressure causes Velocity. That's it! Off the top of my head, V killers in a 25-06 would be a 24" factory gun, with one of the last chambers reamed before the tool was thrown away. They are Not all the same...A custom one-off is perfect ev time.

 

[Bob Nelson 35Whelen]

WOW!! I've never gotten anything even close to that with 100 gr bullets in the 257AI. How long is the barrel?

@Ray B
Mate I get that out of my 25/303 Epps Newton improved and 58 grains of powder with 100 grainers.
A standard Roberts will give a 100 grainers that speed so I'm not surprised you are getting what you do.
By changing to Hogdon superformance I can SAFELY get 3,670fps out of my 25.
Bob

 

[Bob Nelson 35Whelen]

'makes perfect sense...there's much less efficiency w/ the 06 cartridge over the 7x57 (8x57) case, once improved. 'been down this road many times with people (i think it equals the 2506 AI or poss. superior.) The gun was manufactured by a well-known German gunsmith in PA (Paul Jaeger) who knew precisely what he was doing (with Ackley's improvement of a cartridge he knew so well.) Why I got it in the first place! I'll see if i can find some details (did you see the 757AI vs. 280 AI data shown above? it stands to reason the 757 AI clobbers the std 280) and the 257 AI shows even greater improvement. It's known as his best creation. I know the chronograph is ok, as i've used it on many, many different cartridges (and yes, superformance powder sorely disappointed me as it did not live up to the marketing claims on the label! for 22-250. LOL). The chrony doesn't always display what we wish to see...The 06 cartridge (1903?) is John Browning's copy of Paul Mauser's (1895) 57 design. One is LA and the other SA, but once improved, the SA clobbers the LA in .257-.284).

@C.W. Richter
Mate PM me about superformance in your Roberts AI it is very different to using it in your 22/250.
The case capacity of my 25 wildcat went from 47 grains to the top of the case with H4350 to 63 grains of the s as me powder.
Bob

 

[Ray B]

I dug out some records of some chrono's that I did about 20 years ago. The main powders at the time were H4350, 4831 & 870. Results would be different with the powders available today, but for what it's worth for comparison, All three were with 120 gr bullets:

257 Roberts 24" Winchester factory barrel 3013 fps
257 Ackley 22" Donnelly barrel 3120 fps
257 Weatherby 28" Donnelly barrel 3519 fps

The Wby barrel was made with such minimum measurements that loads must be about 10 grains less than factory due to the lack of freebore/blowby.

 

[C.W. Richter]

That seems about right! It also shows how bbl length influences velocities in sm bore calibers. IF 10 gr less than factory (60,) they're right at 257 AI charges (50.) My fav Wby load was 62 gr (w/ similar V in a 26".) As I recall, I was able to get 3,250 using the 120s in the same 26" bbl. Both of your above Roberts/AI data are just fine for deer. The Wby will tend to knock small craft out of the air but radio signal should be good.

 

[C.W. Richter]

@C.W. Richter
Mate PM me about superformance in your Roberts AI it is very different to using it in your 22/250.
The case capacity of my 25 wildcat went from 47 grains to the top of the case with H4350 to 63 grains of the s as me powder.
Bob

it def is a dense powder b/c one can fit 45ish grains in a 22-250 case, whereby others yield only 35ish. that said, it did NOT live up to the marketing claims, which bothered me even more than the "performance" of -200 fps from their literature. it shot just as accurately as other powders, just slower. Also, the supercharger didn't show itself at all during reloading or shooting.

 

[Bob Nelson 35Whelen]

it def is a dense powder b/c one can fit 45ish grains in a 22-250 case, whereby others yield only 35ish. that said, it did NOT live up to the marketing claims, which bothered me even more than the "performance" of -200 fps from their literature. it shot just as accurately as other powders, just slower. Also, the supercharger didn't show itself at all during reloading or shooting.

@C.W. Richter
In my 25 wildcat using H4831sc/AR2213sc my velocity for 100 grainers was 3,440 fps and 115/117grainers 3,270 fps.
Switching to Hogdon superformance the 100 grainers went to 3,670 fps and the larger sizes went to 3,370 fps. A worthwhile gain in both cases.
Bob

 

[Ray B]

With regard to the 257 Wby 120 gr bullet, Hodgdon manual #23 lists 76 gr H870 as max chg yield 3240 fps @53,200psi (maybe cpu). In mine w/28"barrel 75.5 gr 870 had 3687 fps with BRIGHT ejector mark. Five gr below max 71 gr 870 gets 3410 fps which is what I use as standard load for it. At that, I'm still well above the listed velocity and the case life is very good, indicating no high pressure. I don't miss the 100 fps that I'd get by adding the extra powder and neither do the animals.

 

[C.W. Richter]

i used to call my 257 Wbys-the Cannons! it was almost too predictable. Boom-down! lol But, the AI will do the same to about 300, then the animal will take a few steps after that. Still a beautiful thing. Never forget a fellow hunter asking me if i was bringing U. Roy along! LOL (I'm thinking he would bring hearing protection when out practicing on longer-range woodchucks.)