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What Ackley Improved to pick?

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25 January 2009, 01:46
Mohunt
What Ackley Improved to pick?
Looking to make an Ackley to make that will work in a 700 Short Action and give the best performance. Looking to stay at a 22" barrel or shorter, use for coyotes to deer, shoot up to 100 to 120 gr. bullets, so twist advise would be helpful as well. Help me out guys.
25 January 2009, 02:02
vapodog
quote:
work in a 700 Short Action

Make a .260 Remington....it's "AI" the way it stands in it's standard configuration.

Great cartridge for 'yotes and with 120s will kill deer like lightning!
1-9" twist will do fine


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25 January 2009, 02:59
ramrod340
The AIs I tried on a 308 based case was a waste of time and $$. Only real change an AI gives you is a slight change in shoulder the taper is basically the same. For about 1.5 grs of capacity gain just not worth it.

The 260 is a fine round as is the 243. Or be different and go with the 250(whatever it is called)The SA really limits you to a 243 lengtt case. There is always the 6.5-284.


As usual just my $.02
Paul K
25 January 2009, 03:04
<9.3x62>
If you really want an AI - go with the 250-3000 AI or 257 AI. You can have the latter throated to work out with the 2.8" OAL. I've always had extremely good results with Bob in a SA... and in my experience, a 10" twist has worked very well even with the 117-120 gr. bullets.

If it were me, however, I'd build a standard 260 with an 8.5" twist. Great round.

What barrel maker are you going to use?
25 January 2009, 04:31
merlinron
the .260 would be a fine choice. and as ramrod stated, the .308 case doesn't benifit from the ackley improvement as much as other cases. it's pretty close to the ackley idea to begin with.
if you want a true, classic "ackley" for the duty you described, the roberts would be the one, hands down, with maybe the sweede a close second. IIRC, in his writings, ackley claimed that the roberts showed the best overall utilization of his "improved" case design, with the sweede and the 7x57 right behind it. a few years ago, in talking to my gunsmith about the ackleys, of which he is also a fan, he also opined that the roberts showed the most benifit, overall.
just keep in mind that the ackley improvement isn't all about turning a std. cartridge into a magnum and that the design was done during a time when making brass more reuseable was as much or more the purpose of his work on them as getting more balistic performance because he was an accomplished shot that knew a well placed shot was more leathal than a hard hitting bullet.
25 January 2009, 04:44
Mohunt
9.3x62, I was looking to go with a Pacnor barrel. Will there be enough magazine capacity in a standard 700 SA to handle heavier bullets in 257 AI?
25 January 2009, 05:00
<9.3x62>
quote:
Originally posted by Mohunt:
9.3x62, I was looking to go with a Pacnor barrel. Will there be enough magazine capacity in a standard 700 SA to handle heavier bullets in 257 AI?


You'll have 2.8" plus perhaps a tiny bit more. The 115-120 will be seated deeply, but it works out fine. My current 257 (non AI) is a 23" pac-nor SS in the 700 "mountain rifle" contour with a 10" twist - on an early 722 action (the predecessor of the 700 SA). One of the best shooting hunting rifles that I own. If you have pac-nor do the work, know that they tend to run pretty tight chambers.

If you want something even more esoteric that runs close to the 257 AI, try a 25 Souper (aka 25-08). Easy case forming and less likely to give you any feeding trouble...

Just out of curiosity, why the fixation on an AI?
25 January 2009, 05:16
Mohunt
9.3x62, not a fixation just looking for some thing to make out of this SA I have lying around. Something different I can get dies for and without to much work making brass. What else can you tell me about the 25 souper?
25 January 2009, 05:35
<9.3x62>
Nothing more than a 243 neck to 257. Runs Bob+p numbers without too much trouble, but fits better into the 2.8" OAL action than Bob or Bob AI. Super easy case forming - just a tapered expander ball and you're ready to go. RCBS makes dies...

If you're looking for something different, it may be just the ticket.

The 260 is more practical, but I can appreciate the appeal of something more unique.
25 January 2009, 05:39
Mohunt
Other than longer case life or less trimming what kind of velocity gains are people getting out of a 260 AI over the 260
25 January 2009, 06:00
Buliwyf
The .25 Souper. .308 Winchester necked down to .257 caliber.
25 January 2009, 06:01
vapodog
quote:
Originally posted by Mohunt:
Other than longer case life or less trimming what kind of velocity gains are people getting out of a 260 AI over the 260
The gains may in fact be none at all....immesureable.

As to case life the reason "AI" s do so well is that the chambers are custom made for the round and if you go .260 the thing to do is buy the reloading dies first and then get a fired case from someone and full length resize it in YOUR dies and ask the gunsmith to use that case as a go gage in headspacing. In this manner you will achieve the same advantages of the "AI" cases.....and this is simply minimal working of the brass.....the taper and shoulder angle has nothing to do with "AI" brass life....it's custom chambering and minimal working of the brass....


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25 January 2009, 06:04
Mohunt
Buliwyf, what kind of accuracy and velocity can I expect compare to a 257 AI
25 January 2009, 06:24
Mohunt
Vapodog, You make a good point. Possibly a standard .260 should be considered.
25 January 2009, 06:47
plainsman456
the 250 SAV. AI is a good round, as well as the 257 Rob AI.i have both and iuse the 250 for pd shooting and the rob for pd,deer and pigs but i have not shot any bullet heavier than 100 grs. in both.if i need something heavier i just get Nosler parts. and go for it.you will like them.Good Luck
25 January 2009, 07:26
Mohunt
I would think the 250 AI would be a fairly good deer round as well.
25 January 2009, 07:35
<9.3x62>
quote:
Originally posted by Mohunt:
I would think the 250 AI would be a fairly good deer round as well.


Even the standard 250-3000 is a notorious deer slayer. I've had one in my deer hunting arsenal since I was a teenager. It's always delivered. One of my three favorite rounds.
25 January 2009, 07:56
vapodog
quote:
Originally posted by Mohunt:
I would think the 250 AI would be a fairly good deer round as well.

All of the cartridges based on the standard .473 case head in the Remington SA are superb deer rounds.....from the .243 to the .358 Winchester...

You can't hardly go wrong here.


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"Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery."
Winston Churchill
25 January 2009, 08:09
ramrod340
quote:
Other than longer case life or less trimming what kind of velocity gains are people getting out of a 260 AI over the 260

Can't speak to a 260 but in a 243 & 7-08 I saw no increase that I could really measure. These were the same barrels before and after. I even rechamber them without setback so the barrels would be the same length. In both cases I worked up loads to head expansion. After my testing I pulled the barrels and used the action for the next project.

Don't get me wrong I have AIs I have numerous full blown wildcats. In the 7x57 based cases you see more gain for two reasons. The taper allows you to get a greater capacity gain and mostly 257 & 7x57 factory ammo is loaded to lower pressure. I have spent a lot of time and $$ over the years and only thing I really proved was that at egual pressure a 1% velocity for 4% capacity gain in an 06 based case is a really close rule of thumb. In a 308 the gain is less in the 7x57 it is a little more. The majority of the gain seen and/or claimed from an AI is pressure related often very high pressures.

I've seen two barrels in a std chambering give 100-200FPS different velocity. So yes someone will have an AI with a huge gain over another rifle chambered in the parent. Is it the AI or a different barrel


As usual just my $.02
Paul K
25 January 2009, 09:53
PepeLp
I've had several AIs. The only one I think was worth the trouble is a .243. The Ackley conversions give slight velocity gains with the same pressures. The straight case does do a great job of masking pressure signs. I think a lot of people who get big velocity gains are running much higher pressures than they think. (Dangerously high pressures.) In my experience, the cartridges won't feed as well either. Overall, not worth the time or trouble, but fun to play with if you want a wildcat.


It's all in the reflexes.
25 January 2009, 17:34
Bobby Tomek
The cartridge offering the most from being AI'd is the old 250 Savage. Not only do you get a nice velocity gain, but what I feel is the main attribute is that case trimming is MUCH less frequent.

If you do go that route, Re-15 is a great place to begin, especially with 85-100 grain bullets.


Bobby
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25 January 2009, 17:49
DMB
quote:
Originally posted by Mohunt:
Looking to make an Ackley to make that will work in a 700 Short Action and give the best performance. Looking to stay at a 22" barrel or shorter, use for coyotes to deer, shoot up to 100 to 120 gr. bullets, so twist advise would be helpful as well. Help me out guys.


I have this thing about AI'ing cartridges. There are some cartridgets that should be AI'd, and some that no way should they get the AI treatment.
There are two cartridges that I have in the standard chambering, and the AI version. The one that I have that you should consider, is the 250 Savage AI. I personally think it's the very best of all the AI chamberings available. But, YMMV. You may like one of the others.
It shoots to the same velovity level as the standard 257 Roberts, and does so in a short action, with grace and dignity I might add.. Big Grin
The standard 257 Roberts works in a short action, and I have three rifles in 257 Bob so fitted, but the 257 Bob is not as dignified, nor as graceful.. Big Grin The 250 Savage in a short action is a match made in heaven. Mine is very accurate, shooting the 87, 90, and 100 grain bullet offerings into less than 1/2" groups for three shots at 100 yards. It's a Rem 700 CDL with a Shilen 1-10" twist barrel. I only shoot bullets up to 100 grains in mine, and bought the 1-10" twist barrel for that reason.
The other AI I have is a 223 AI. Same words go for it as far as accuracy goes.

Don




25 January 2009, 18:04
Mohunt
What kind of velocity gains can I reasonably expect in the 250AI
25 January 2009, 18:16
DMB
The 250AI velocities, for all intents and purposes, equal those of the 257 Roberts.




25 January 2009, 18:50
Mohunt
Ok all I have narrowed it down to a 250AI or 25 souper, convince me to make a decision between the two.
25 January 2009, 19:26
Buliwyf
Hello Mohunt,

I put a lot of importance on brass quality. I beleive brass preparartion is the cornerstone of accuracy. I have not researched 250 Savage brass availability or quality of brass source. The .308 Winchester brass is from outstanding quality sources and readily available. The Souper is superb with 85-87 varmint bullets reaching way out on windy days. With 115-120 gr the Souper has powder capacity to push these to 3000fps which I like in case of "longer" small big game shots. I think 1:10 twist would be the answer but you can call Krieger Barrels and talk with a technician.

I do not have a 25 Souper, my hunting partner has one and would not part with it. I have a 25 wssm -I have gotten addicted to the little buggars Big Grin The Souper, Bob AI, 25 wssm are perfectly balanced case capacity:bore volume cartridges. My buddy's Souper is extremley accurate. My 25 wssm is also MOA.

Good luck on whatever you decide.
25 January 2009, 19:38
Tyler Kemp
6mm Ackley with a 1-8" twist! Superior ballistics...


Love shooting precision and long range. Big bores too!

Recent college grad, started a company called MK Machining where I'm developing a bullpup rifle chassis system.

25 January 2009, 19:51
Mohunt
I just looked on the Pacnor website and they do not show a 25 souper or 25-08, was going to have them do the job since they have done well so far with others I have done.
25 January 2009, 20:10
<9.3x62>
quote:
Originally posted by Mohunt:
I just looked on the Pacnor website and they do not show a 25 souper or 25-08, was going to have them do the job since they have done well so far with others I have done.


Give them a call, they may well have it or can get it easily enough. Given your preference for a 22" barrel, I would think that the 250 AI or Souper would be ideal... 10" twist will work fine.
25 January 2009, 20:12
Buliwyf
I see that. Pacnor has some pretty Wild wildcats not to have the 25 Souper listed. It's worth a call to ask them about it.
25 January 2009, 20:40
Mohunt
One thing I need to know before I make a decision also is what kind of velocity and or accuracy gains do you all think I can get from a 25 souper over the 250AI.
25 January 2009, 20:47
Dr. Lou
quote:
Originally posted by plainsman456:
the 250 SAV. AI is a good round, as well as the 257 Rob AI.i have both and iuse the 250 for pd shooting and the rob for pd,deer and pigs but i have not shot any bullet heavier than 100 grs. in both.if i need something heavier i just get Nosler parts. and go for it.you will like them.Good Luck


Me too, especially the 250-3000 Savage. Lou


****************
NRA Life Benefactor Member
25 January 2009, 21:04
Buliwyf
Hard to comment on accuracy gains of the Souper over the 250AI. The .308 Winchester is considered an inherently accurate case design. I don't have experience with the 250-3000 Savage or the 250AI.

Velocity wise:
25 Souper 87 gr 26" bbl app 3450fps max
25 Souper 117 gr 26" bbl app 3000fps max
Re: A-Square Any Shot You Want Manual

250-3000 Savage 87 gr 24" bbl app 3100fps max
250-3000 Savage 117 gr 24" bbl app 2800fps max
Re: Hornady Sixth Edition Handbook

I would estimate 30fps gain/loss per inch of barrel. I would estimate an additional 100fps -150fps gain for the AI improvement over standard 250-3000 Savage.
25 January 2009, 21:25
Mohunt
Well I emailed pacnor if they can do a 25 Souper, will let you know.
26 January 2009, 00:21
Mohunt
Does anyone know anything about a 25 humdinger?
26 January 2009, 00:30
Buliwyf
That's a new one on me. Do you know what the parent case is? Short action case?
26 January 2009, 00:37
Mohunt
Best I can tell it must be close to a 25 souper but it has a 45 degree shoulder. It uses a 243 case.
26 January 2009, 01:00
Steve E.
Obvious choice given your parameters would be the 250 Savage Ackley Improved.
I have the,
280 Rem Ack Imp
257 Robt Ack Imp
250 Sav Ack Imp
an love them all.

Steve E......


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USAF Veteran
26 January 2009, 01:01
Alberta Canuck
I like AI cartridges, at least pretty much all of the ones which are straightened and get a sharper shoulder from the conversion, anyway.

Why do I like them? Brass life, maximizing the capacity of the brass I already have, and most of all, the feature which some don't like...the ability to "mask" high pressure signs.

Myself, I do not care how high the pressures actually are or aren't, so long as it doesn't show up in the performance (failure) of my brass. I prefer to view "masking" pressures as "handling high pressures better". Also, I don't consider any pressure levels unsafe unless they do destructive things to my brass or rifles.

So, if "Ackleyizing" my brass allows me to run higher pressures and get better results in terms of brass life and velocities (even slightly), I can live with that. Especially if I am ordering a new barrel anyway. Generally, the Ackley chamberings don't cost any more to buy than the standard ones.

YMMV, so I am just telling you why I like them. Am not suggesting anyone else should agree, and really don't care whether they do or not.

Best wishes in your new barrel decision. Have fun. That's what it's all about anyway until we HAVE to hunt for food like in the old days.

P.S., my choice would be:

1. 250-3000 AI, because it can still use factory .250 ammo, which the Souper cannot.

2. the .25 Souper because it IS a very good round.


My country gal's just a moonshiner's daughter, but I love her still.

26 January 2009, 01:05
DMB
quote:
Originally posted by Mohunt:
Well I emailed pacnor if they can do a 25 Souper, will let you know.


My next rifle, right after the new Model 70 I ordered arrives, will be a 25 Souper, sometime this spring I hope.
I've had money down on the M-70 Featherweight in 7-08 for about three months now.