Why Ackley Improved?? Vs std choices

[FEENIX]

What is reasonable? I don't see 270AI in their charts. So, how much is their custom in your experience? ….thinking type S FL and Micro seater…

I got mine in 2012, and it is not a microseater. IIRC, I paid <$100 for it. Expect to pay $225 and up for a micro S match bushing 2 die set, but it is best to call them directly.

Actually, that is a good option. When I kick this off finally, I suspect there will be more rpm dies. Peterson is making brass. Are the dimensions good on the SAAMI reamers?

WBY now has them for $125/50 and Peterson via Graf for $115/50.

Call Manson, JGS, etc., to verify. Stay your course, and you'll be fine.

Good luck!

ADDED: I have an R700 in .30-06 and am thinking of re-barreling; I might have to revisit my previous goal of 6.5 WBY RPM.

 

[Alibiiv]

I love the look of Ackley shoulders with bullets sticking way out…..but I also like reasonably priced die sets!

So, that makes me think I should be looking at a 270 Win, 6 Creedmoor, 6.5 Creedmoor, 25-06AI, or ……for a next 473 bolt face barrel chambering. I'd like to go way below 300, run fast twist barrel and high bc bullets.

I'm thinking 6 or 25 cal honestly.

So, what can I get does for?

What real benefit am I getting choosing AI or Sherman calibers?

Great thread. First and foremost is the fact that if one goes Ackley Improved components are going to be available and not proprietary. I do not like being held ransom because some company wants to hold a particular customer base; capitalism dictating policy. Look at the Nosler 26, 28 and 30 cartridges. Usually the components are not available, or when they are the brass usually is $2-3 a piece. What I have found is that with the Ackley Improved cartridges the parent cartridges/components are usually quite available. Plus there usually are not any modifications needed in the feed rails or the bolt face. I am not too familiar with the Sherman cartridges, so I will stay away from them. Also with the Ackley Improved, especially in the calibers from .284 down one gets a pretty good increase in performance from straightening out the case body and putting a 40 degree shoulder on that case. Also I strongly that if you go with a build from the .284 caliber and down you go with nothing less than a 26 inch barrel to get all the horsepower that one can get from that extra powder capacity. I believe that there are some cartridges that will give one more bang for the buck than others. If I were to be looking to run a wildcat cartridge in 30-06, I believe that the Gibbs would be my choice over the Ackley Improved only because of the increase of powder capacity in the Gibbs. Please no insult to the 30-06AI folks here. Presently I have a .270 Ackley Improved rifles. I built these rifles (one for my son) for whitetail deer hunting. The rifles are Ruger 77s, 26 inch, 1:10 Lilja barrel. The round is giving me between 3100-3300fps with the 150gr ABLRs, and the round is extremely accurate. This performance puts the cartridge in the 7mm RemMag range, and with a lot less powder. I was strongly looking at the .280 Ackley Improved, however at the time of the build Nosler had me so confused between the actual Ackley Improved cartridge and their "proprietary" cartridge case that I did know what direction to go in. When I found that Nosler had made "their" SAAMI approved .280 AI cartridge-proprietary-I went with the .270AI. The dies are sort of incidental to me. Sort of like owning a boat. If a boat owner is concerned about gas then they probably shouldn't own a boat. I have posted a couple of attachments. The target I posted is a 300 yard target that was shot with a 26 inch, "sporter" barrel. I do not know why this cartridge has not shown the interest that it deserves. These attachments have been posted on this forum in the past, but...they are good examples of the .270AI. Good luck with your build.

 

[Mike Matteson]

Having difficulty sourcing a blank in 7" twist here. Importing barrels privately now is cost prohibitive due to import/export duties.

Cheers.
P.S. Nobody is willing to mark the postal box as "Tomato Stakes Only"

There seem to be a problem in getting 7 twist rate barrels blanks all over the place. I know I have my smith place orders with 3 different places in trying to a barrel for my 25 build. Reamers have been slow to come by. also. I had started a 25 cal over a year ago. Still waiting for a barrel. The makers of a barrel sent out a wrong twist barrel and then tried to came that what was order. We had the back and stop that shi*t.

 

[fruitnut]

I took my first elk with a 25-06 about 40 years ago. Back when the bullet selection stunk. Shot it with a 110 Hornady of some sort that was way too soft. So, I knew it had to be placed right.

Now days it seems to me that the 6.5 PRC and 7 PRC among others do everything any improved 06 case will do. No need to fire form or buy more expensive dies.

Some people AI and then shoot bullets with low BC for weight and all the advantage of the AI is piddled away past 300 yards.

That said I wish I had my 25-06 back as an AI with a fast twist barrel. It was a nice gun.

 

[Koda_]

I think it has to do with the fact that there are issues with such extremely fast twist barrels. Manufacturers want satisfied customers. Had a discussion with a premium barrel maker over a 7 tw 6mm. He wanted more details about what I was doing before proceeding. His concerns were bullet failure as the throat eroded. Not saying he would refuse to sell me what I asked for, but would do so with the full knowledge of what to expect and what he may warranty if said problems arose. FWIW, this was for a 6 Sherman Max build. Should push 112-115 gr to around 3400 fps.

Is this really a problem though with modern bullets?
The only caution ive heard of is spinning jackets off, but isnt that an issue of the old days? I havnt tried very light bullets in my 7twist 25-06ai yet, but did try some standard 120gn Nosler Partitions and those shot fine, even with the huge jump to the lands.

My guess is the 7 twist isnt popular because many people are just not aware of the advantages and many still feel jacket separation is a thing. My take is just dont use those bullets. Theres also the fact that the vast majority of standard twist rifles really do shoot just fine, so its going to take a while for people to accept the smaller incremental steps in rifle improvements. Similar to the PRC factory calibers... The benifits are there, but the "need" isnt that great.

 

[Mike Matteson]

Is this really a problem though with modern bullets?
The only caution ive heard of is spinning jackets off, but isnt that an issue of the old days? I havnt tried very light bullets in my 7twist 25-06ai yet, but did try some standard 120gn Nosler Partitions and those shot fine, even with the huge jump to the lands.

My guess is the 7 twist isnt popular because many people are just not aware of the advantages and many still feel jacket separation is a thing. My take is just dont use those bullets. Theres also the fact that the vast majority of standard twist rifles really do shoot just fine, so its going to take a while for people to accept the smaller incremental steps in rifle improvements. Similar to the PRC factory calibers... The benifits are there, but the "need" isnt that great.

That's the way seem to be headed. All copper bullets and faster twist rates. Mexilfornia requires all copper bullets and no lead shot now. Far to many greeniee in this state. That's why I generally stay in Montana. I didn't bring any left wing idea with me either. The other problem is getting faster twist rate barrels. The cost of setting up a new barrel to handle the all copper bullets. I have make the determination that if need a different barrle I will have it built as a new rifle unless the barrel is gone anyway. When I do load development and get what I want or espected from the rifle, I stay with that. So I tend to not burn out barrels. I generally have a plan as to what I am going to use the rifle for and bullet weight I going to use. I work around that bullet weight and velocity, plua grouging in and under 1/2" @ 100yds. See how they do down ranges. I get my time on a rifle by shooting varmits. That tunes the eyes and trigger finger up and concentrate on shooting practices.

 

[Muddyboots]

I love the look of Ackley shoulders with bullets sticking way out…..but I also like reasonably priced die sets!

So, that makes me think I should be looking at a 270 Win, 6 Creedmoor, 6.5 Creedmoor, 25-06AI, or ……for a next 473 bolt face barrel chambering. I'd like to go way below 300, run fast twist barrel and high bc bullets.

I'm thinking 6 or 25 cal honestly.

So, what can I get does for?

What real benefit am I getting choosing AI or Sherman calibers?

Best way to maximize traditional cartridges is to chamber in longest maximum magazine capacity action for the specific cartridge. I built a .270 Win on 700 LA with 0.290 freebore so I could seat longer heavier higher BC bullets out matching magazine to jump. Huge difference in overall performance from "standard" chambering. Essentially you are building a cartridge same way the 6.5 Creedmoor was done to take advantage of longer higher BC bullets. Cartridge Efficiency is easier this way.

 

[Hugnot]

Another worthy consideration is the tiny .223 AI. It does better than expected in a 7.5 twist with 75 ELDM's or 75 VLD's at 2800 fps. A real good rodent shooter & other small stuff with a 10 or 12 twist & 53 grain H VMax bullets at close to 3,500 fps.

A good brass choice would be 250 piece bags of LC 5.56X45's. Fireform with any cheap .224 bullet suitable for twist rate.

A huge variety of powders will work. Dies are easily found & cheap. A huge variety of cheap .223 brass is easy to buy.

Lotz of shots without trimming & more speed. Get a nice chamber requiring a slight crush fit for 1 time fire form then buy lots of brass. If cheap .223 brass is 1X fired use a small base die on first F/L size.

 

[Coyote Shadow Tracker]

I love the look of Ackley shoulders with bullets sticking way out…..but I also like reasonably priced die sets!

So, that makes me think I should be looking at a 270 Win, 6 Creedmoor, 6.5 Creedmoor, 25-06AI, or ……for a next 473 bolt face barrel chambering. I'd like to go way below 300, run fast twist barrel and high bc bullets.

I'm thinking 6 or 25 cal honestly.

So, what can I get does for?

What real benefit am I getting choosing AI or Sherman calibers?

We have not read all the Posts here and there are many more on other Posts asking you question about the AI.
Bullets sticking out of the case is determined by the design & weight of the bullet. Then you have to worry about if the cartridge will fit your MAGIZINE or go with a single shot.
Personally, we have changed some cartridges to AI and I WOULD NOT EVER DO IT AGAIN. If I want to get 1-200 more fps velocity I would just go to another Cartridge.
We built a CUSTOM .338LMAILS and it cost a small fortune for the Custom JGS REAMER, then Custom Whidden Bushing Dies, and not forget that you need to Fireform the Brass. We bought a Hydro Form Die from Whidden $$$$S. Then need a LA Action and Mags to hold the long cartridges or Single Shot like we did.
Now we could have thought about just keeping the .338LM or I should have gone to a .338NM.
If you have the funds to go AI and that is what you want GO FOR IT!
We have nothing against making an AI, BUT WE WON'T MAKE ANY MORE, IF WE NEED MORE fps VELOICITY WE WILL JUST GET THE NEXT BIGGER CARTRIDGE!
We made this .338LAMAILS specifically for shooting 3K and not having to go to a 375 CT.

If you are just hunting with a .260Rem, .270 Win. 30.06 just stick with them and factory without going to Custom. Do you really want to spend extra $$$ and time to make an AI Case for just a few extra feet in fps Velocity??? I choose accuracy over FPS every time. If you have a good hunting rifle, cartridge scope just use it for it's capabilities to cleanly kill and harvest the animal you intend to use it on.
Just an example if you have a .270 Win and want more fps get a .270WSM same with a .300 like a 30.06 to a .300WSM. As far as your 6.5mm the .260REM is a fantastic cartridge. We have had six of them. If you want something faster go with a 6.5PRC.

Good Luck in your quest for a Cartridge(s) that you want to build and shoot!
Len & Jill

 

[Tiny Tim]

Tim that looks like a VERY conservative velocity.?
Is that where you intend to run them, or a top speed?

Suspected. Won't know for sure til it's up and running.

 

[Tiny Tim]

Is this really a problem though with modern bullets?
The only caution ive heard of is spinning jackets off, but isnt that an issue of the old days? I havnt tried very light bullets in my 7twist 25-06ai yet, but did try some standard 120gn Nosler Partitions and those shot fine, even with the huge jump to the lands.

My guess is the 7 twist isnt popular because many people are just not aware of the advantages and many still feel jacket separation is a thing. My take is just dont use those bullets. Theres also the fact that the vast majority of standard twist rifles really do shoot just fine, so its going to take a while for people to accept the smaller incremental steps in rifle improvements. Similar to the PRC factory calibers... The benifits are there, but the "need" isnt that great.

It's likely an issue of what people know or don't know in their expectations. Just sharing my experience with a premium barrel manufacturer. When I told him my plans, he was comfortable. I assume some people are trying to run hyper speed (4000fps+) and when they fail, they try to blame someone else.

 

[MagnumManiac]

I do not see an issue alone with twist rate, my issue with those .224" blanks were a combination of the number of grooves (3) and the twist rate combined with using thin jacketed bullets.
Although I have heard and seen similar issues with certain brands in 25 and 6.5, the issue there is again the use of thin jacketed bullets.
I blew the heck out of Speer 125g TNT bullets in both my 300WM & 300 Weatherby because I didn't read the warning about max velocity…spectacular blue coloured 'puff' at about 25 yards from the muzzle. No bullet or fragment even hit the 50 yard target.
I know for a fact that a certain target bullet brand in .224" does not like my 3 groove 7" twist 32" long barrel in any weight, the rifling is just too sharp and wide for it, yet if I run the 4 groove barrel I have no issue…
Really liking the RDF in .22" cal these days.

Cheers.

 

[Hugnot]

The Miller Sg calculator is used by many bullet makers including Berger. According to Miller & others Sg values run from 1.5 to 2.0 for best accuracy.

The Miller Sg calculation method appears to have problems when the center of bullet mass & center of bullet pressure are separated more than that of conventional cup & core bullets. Sg values for bullets derived by using bullet length, like the Hornady ELDVT, indicate marginal adequate Sg values of about 1.4 but stability is inadequate as shown by inability to group. Going to a faster twist fixes the problem.

I kind of like 5 L&G R type rifling meaning the junction of land & groove is sloped vs. right angle or 90 degree. I think this is kinder to bullet jackets.

I would not expect fyne accuracy with a subby bullet intending for slow twist BR shooting having a Sg value over 4.0 that did not show signs of bullet break up. I got real fyne accuracy from the stubby 125, .308 TNT from my 12 twist .308W just under 2650 fps (like put less 4895 in load). I used the 125 for 100 yard NMC on reduced size targets (reduced 600 yard target X ring about the size of a nickel) with great results - low recoil great for rapid fire at 100 yard 200 & 300 reduced size targets. The 12 twist did great with 168 match bullets at about the same velocity at actual 600 yard.



The .308 Win is sort of an improved cartridge in that it has very little body taper and a moderate shoulder angle. .308 Win much better match cartridge than .30-06 as indicated by its replacement of the 06 for NMC.

 

[lancetkenyon]

It's likely an issue of what people know or don't know in their expectations. Just sharing my experience with a premium barrel manufacturer. When I told him my plans, he was comfortable. I assume some people are trying to run hyper speed (4000fps+) and when they fail, they try to blame someone else.

Depends on the bullet too.

A 6mm 85 VMax in a 1:7" will vaporize @ about 3650fps...