Ackley Improved

[SJB358]

I'd really love to have a crack at a 6.5 Swede Improved.

Anyone done that one before?

Bob, now your talking! Had a buddy at work take some NRA gun smithing class. They basically show up with an action, barrel and stock. An instructor teaches them the whole works and when my buddy asked me what he should chamber I said 6.5 Swede Ackley. I never owned one or even shot one, but he did it and it turned out great. He used Swede ammo to fireform cases and man, that is a cool cartridge. I think that sorta cartridge in a Featherweight or Mountain Rifle sorta trim would be hard to beat in the mountains.

Heck, just the plain old Swede is a performer with modern data....

 

[Dwh7271]

Guy,
If you mean velocity jumps, then I'd have to say the 22 KHornet(not exactly called an AI but is the same idea),22-250 AI, 250 AI, 257 AI, 260 AI, 7x57AI, 280 AI, 30-30 AI and I am certain I missed a few. The above show a couple hundred fps advantage over the parent. Mashburns in many cases were improved cartridges but with a 30 degree shoulder, I believe, rather than a 40 degree. Scotty would be better able to answer on those.
People have improved darn near all of them at one time or another but in some cases other than the need to trim less often, the gains were neglible.
IMO, the more sharply tapered cases seem to reap the greatest gain from improving.

 

[Ridgerunner665]

I think efw meant the 7mm Rem SUAM and the 280 Ackley have the same capacity...they do.

 

[Guy Miner]

DWH, Right, I was thinking in terms of actual velocity increases.

Haven't played around with the AI cartridges myself. Have read that some, like the .257 AI, demonstrate very good gains, while others show very little improvement.

Thanks, Guy

 

[Thebear_78]

Easily biggest velosity jump is the 300 h&h. The 250 savage, 22-250, and 257 bob are good ones too. The biggest velosity jump is heavily tapered parent cartridges


Sent from my iPhone using Tapatalk

 

[Guy Miner]

Easily biggest velosity jump is the 300 h&h. The 250 savage, 22-250, and 257 bob are good ones too. The biggest velosity jump is heavily tapered parent cartridges


Sent from my iPhone using Tapatalk

That makes a lot of sense, as the increase in volume would be the greatest. Come to think of it, a .300 Weatherby Mag is pretty much just a blown out .300 H&H.

Not an Ackley Improved, but very much improved.

Guy

 

[Thebear_78]

Thats what I was talking about, same concept and biggest increase


Sent from my iPhone using Tapatalk

 

[Ridgerunner665]

Guy,

Check this out...its a small PDF file, no huge download...comparing many of the AI's to their parents.

http://gunloads.com/castboolits/attachm ... 1295041970

I'll sure be glad to get mine (M48 280AI) no idea yet when that might be...almost 8 months in...shouldn't be long now.

 

[nvbroncrider]

It's all about case capacity I need to get a picture of the 7 Gibbs next to the 280 and the 280AI.

My 280AI really performs well with the 160's but drops off a ton with the 175's a lot more than I thought it would. 3160 with the 160's 2860 with 175's book max loads and they do show signs of pressure if I bump them anymore. QL with that rifle shows with the 28" barrel I should be pushing 3150 with 160's and 3000 with 175's

 

[efw]

I think efw meant the 7mm Rem SUAM and the 280 Ackley have the same capacity...they do.

Yeah thanks sorry my bad I 'misremembered' :twisted: .

 

[efw]

Easily biggest velosity jump is the 300 h&h. The 250 savage, 22-250, and 257 bob are good ones too. The biggest velosity jump is heavily tapered parent cartridges


Sent from my iPhone using Tapatalk

That makes a lot of sense, as the increase in volume would be the greatest. Come to think of it, a .300 Weatherby Mag is pretty much just a blown out .300 H&H.

Not an Ackley Improved, but very much improved.

Guy

Yep and in addition to taper don't forget the other thing those parent cartridges that benefit most from Improving have in common; relatively low SAAMI-approved operating pressures.

250-3000, 257 Rob, 280 Rem, and 300 H&H all have rather low max pressures mostly (280 is a mystery as to why) because of the rifles they were often chambered in early on.

You take a (relatively) modest gain in capacity and add a significant increase in pressure and get significant gains velocity-wise.

 

[Thebear_78]

280 was hamstrings by remington auto loaders, it came out in them and they had extraction problems with hot loads


Sent from my iPhone using Tapatalk

 

[preacher]

In a 22" bbl, or shorter, the most efficient/gain for me has been the 35 Whelen AI, 30-30AI, 6mm Bullberry ( a 6mm/30-30 Improved) 17 K Hornet. In 24" bbl it was my first, a .257 Roberts AI. and a .375 H&H reamed out to the .375 Weatherby ( an Ackley with a rounded shoulder is all). My biggest disappointmets were two 30-06 AIs, one in 22", one in 24"...not worth the trouble, and my first/only .280AI in a 22" bbl. The 30-30 had to be dialed back as its brass is too thin and the Mod 336 action too springy. A tight single shot 30-30AI with brass made from .375 Winchester brass would be a holy terror! On the other hand, for most deer hunting, a regular 30-30 at regular ranges is just about perfect as is, ha.

 

[muleman]

My cousin once had 7mmx30-30AI(7x30Waters?) in a 24'' Thompson Contender and it really scooted. I've got several AIs and like them very much. As others have said; the most dramatic differences are found when you compare older lower pressure rounds with sloped case walls reloaded in AI'd cases to higher pressures in modern guns. I've found that pressures being equal the AI'd case will yield approx. 100fps. more. My favorite thing about AI'd cases is the lack of trimming that needs to be done. My 22-250 cases needed to be trimmed after 3 firings. My 22-250AI has some cases that have been fired 8 times and are still good to go. The best cases for an AI conversion are the 22-250,220 Swift, 6mm, 257R, 7x57, 300HH, 375HH. The 280AI is a great one(I have one) but if you reload a .280 to the same pressure as a 280AI they are pretty close. The straighter cases like the .308 family and 30-06 family don't see much improvement in speed. If I ever do another 35 (or bigger :shock: ) Whelen I'll probably AI the case to get a more pronounced shoulder. One of the things you give up though is truly slick feeding and extraction. A lot of those older rounds have a military or dangerous game heritage and they were designed to feed and extract well every time in all conditions. All my AIs function very smoothly but I don't drag them through mud and sand or load with Cordite or hunt in 100+ degree weather.
I'd have to say my favorite is my 257Roberts, built on a Turkish Mauser with superb metal work. I'd like to stock it in nice Black Walnut and add a three position safety but every time I think about doing that the devil sitting on my other shoulder tells me to build a Win 70 in the same chambering instead :twisted: .

Scott

 

[Vince]

I did a little more research and didn't find the gains as worth considering for the 30-06.
Maybe I'm missing something but looking at the 165/168 and 180 grain bullets using IMR 4350 I'm not seeing much, if any, velocity gain to warrant the extra work of having an AI in the 30-06.
I've decided to stick with the 30-06, I'll have two of them, my .338 Win Mag, and 6.5x284 as my main big game battery. The Nosler Custom will be my main rifle with it's 26" barrel but I'll use a 22" barrel when the situation warrants.
I've never been a fan of the 30-06 and I have no reason for why I've suddenly jumped on the old traditional cartridge like I have. Maybe it is because I've shot the magnums and don't feel I have anything to prove with them as far as my ability to shoot them. The 6.5x284 is a good shooter, or was, but I started developing pressure issues with a previously proven load. I guess I just wanted something easy. Easy to load for, easy to shoot, and easy to find factory ammo for if needed.

Vince

Sent from my SGH-M919 using Tapatalk

 

[Ridgerunner665]

The 30-06 is great Vince...easy, reliable, and affordable.

The old saying...the 30-06 is never a mistake....is true.

 

[DrMike]

The 30-06 is great Vince...easy, reliable, and affordable.

The old saying...the 30-06 is never a mistake....is true.

True, dat. I own no AIs, not because they are bad cartridges, but because there is still only so many days in a week. The velocity gain isn't as much as some expect. The primary draw for me would be simply that the cartridge exists. On the other hand, the parent cartridge also exists, so that attraction isn't that great. Still, I've worked up loads for quite a few AIs of various sorts, and each was fun.

 

[SJB358]

My only cartridge that could be considered an AI would be the Mashburn, but it doesn't exactly fit as there isn't a parent cartridge..

My son does have a 300 Wby... I guess you could think of it as the 300 H&H AI... :lol:

 

[Charlie-NY]

I built a 6mmAI and a 22-243AI. Used them both extensively to shoot groundhogs. While I really enjoyed the AI experience, I ultimately returned to standard cartridges. I no longer have the time or inclination to blow out cases in my custom barrels.
Currently shooting a 6.5x284 and a 22-243 (plain) and am very happy with them both. Groundhogs can't tell the difference.

 

[IdahoCTD]

I think if I was going to do an improved 30-06 type case it would be a 30-280AI or a 300 Sherman for the additional capacity. All it would really be is a 300saum without fireforming. I've had and still have numerous improved cases. Presently I have a couple 243AI's, a 308 Baer (8mm Rem mag necked down and blown out or a 300 H&H Imp.), 30-8mm Rem Mag (I still use 300 and 375H&H brass to form these when I can get Winchester brass), 30-338 Norma Imp, 30-338 Lapua Imp, 30-378 Imp, 338 Baer's, 358STA, and 375-358STA.

As Scott mentioned, one of the nice things about improved cases is the lack of trimming required. The additional capacity is never a bad thing either. I think Ackley said the 250AI had the largest gain out of all of his wildcats. It's kind of funny how many calibers used now are based off of a improved 250 Savage case. Many of them are use in benchrest or other forms of competition.