I "googled" this but couldn't find an answer.

Some examples, but not a "list".

I know that cases W/a lot of taper & slight shoulder angle benefit the most.

I am fond of the 250sav ai and have seen a performance boost when plugging pds at long range 400+ yards.
I also have the 257rob ai and the 22-250ai.
I am liking the 257 when launching 100-120gr bullets.
Some folks will say that it isn't worth the trouble fooling with the brass and keeping the pressures at the factory levels.
The increase comes when you match the cartridge to your style of shooting and the rifle.

quote:

Originally posted by grizz007:
http://www.shootersforum.com/showthread.htm?t=5813

Great link.

The 6.5X55 A.I. was particularly interesting.

My 1st reloading experience other than my old 16ga Lee Loader in a box was W/an 8mm-06 A.I.

Truth be told, I'm getting within 125 fps of that 8mm Wildcat's performance W/an 8X57IS loaded up to the 60,000 psi pressure range.

But, those 8mm-06 A.I cases seldom needed trimming & never showed any sign of insipient case head seperation even when loaded full bore 8 times or more.

Invariable, the cases only "wore out" when the primer pockets became loose after being reloaded many times.

My 8X57IS cases need trimmed after 2 loadings.

Increased case life @ higher presure is a real life trait of the "Improved" cartridge.

Look @ all the new "fat" magnums. Straight case walls W/steeper shoulders.

P. O. Ackley's "Improvements" look like they really were valid to me.

quote:

Originally posted by wildcat junkie:
I "googled" this but couldn't find an answer.

Some examples, but not a "list".

I know that cases W/a lot of taper & slight shoulder angle benefit the most.

Well...I'd guess a 300 H&H would make a top ten of most % improved.

quote:

Originally posted by RaySendero:

quote:

Originally posted by wildcat junkie:
I "googled" this but couldn't find an answer.

Some examples, but not a "list".

I know that cases W/a lot of taper & slight shoulder angle benefit the most.

Well...I'd guess a 300 H&H would make a top ten of most % improved.

Yep, rated #7 according to the link posted above.

Before I look at the link, I'm going to guess 30-40 Krag, AI because it's really tapered and has a long neck that can be ironed out for more powder space.

Plus, I can't wait to build one.

quote:

Originally posted by skl1:
Before I look at the link, I'm going to guess 30-40 Krag, AI because it's really tapered and has a long neck that can be ironed out for more powder space.

Plus, I can't wait to build one.

You're close, the Krag is #2.

Build your own list. Start with a case normally loaded to a low pressure. Add extreme body taper. Blow it out add a 40deg shoulder and then stick it in a new manufacture rifle and then load it to 65,000+. Smaller calibers will give your the quickest gain. If you want to add in a long neck them make a Gibbs and move the shoulder forward.

Some of the Ackley cartridges are better then others. Some don't provide much of an improvement at all. All of the AI cartridges are loaded to the max. Many people have tried to duplicate Ackley's published velocities without success and many articles have been written that criticize Ackley for listing what modern equipment demonstrates were excessive loads.

Any comparison of standard cartridges to their AI counterparts is invalid unless one considers the pressures of the two cartridges. For example, a factory loaded 180gr 300H&H makes 2880fps at the SAAMI max pressure of 54,000cup. The AI cartridge produces 3200fps with the same bullet. The 300AI volume approximates the 300 Weatherby volume so it is no surprise that Weatherby lists 3220fps for their 180gr load. Since the Weatherby cartridges are loaded to SAAMI pressures of 65,000psi, and since the 300AI produces similar velocity using similar powder charges, then it follows that the 300AI must be loaded to about 65,000psi. Therefore, an accurate comparison of how much the AI has "improved" the 300H&H must compare the 300AI velocity with the velocity of a 300H&H when both are loaded to 65,000psi. When you do that you will find that velocity figures will be more like 3200fps for the AI and 3150fps for the H&H.

So let's pull out Ackley's own book, Handbook For Shooters & Reloaders - Volume I, and see what he says. For the 300H&H Ackley lists 180gr loads at velocities up to 3055fps. For the 300AI he simply states, "Loading data is the same as for the 300 Weatherby". Looking at the Weatherby data he lists 180gr loads up to 3015fps. But wait, what did he improve? The answer is in his description of the 300H&H where he criticizes the steep body taper and long shoulder because, he says, the cartridge is subject to case head separation when reloaded "a few times". He goes on to state that the 300AI and 300Weatherby eliminate this "trouble". So the "improvement" in this case is cartridge reloadability. Clearly, if loaded to similar pressures, the AI version offers little in the way of any velocity improvement.

Why is this important to know? Well, if you have a rifle that shouldn't be used at the pressures of a 300 Weatherby then you shouldn't be chambering it for the 300AI. If you are using a rifle that is made for the kind of pressures the 300 Weatherby produces then chambering it to 300AI will give you negligible velocity increase over similarly loaded 300H&H cartridges. Since the 300AI is a handloading affair anyway, then you might as well keep your rifle as a 300H&H and just reload for a little more velocity.

Doing a similar comparison between the 25-35 and the 25-35AI shows a velocity improvement from 2450fps to over 3100fps. That is a very substantial increase even if we assume Ackley loaded the AI version hot.

Ackley had some interesting things to say about the 250AI. He claimed that it was one of the best improved cartridges. He went on to state, "It shows a greater percentage of increase in velocity than almost any other."

What you get with increased powder capacity is a situation of diminishing returns. The smaller capacity cases like 22 Hornet, 25-35, 30-30, and 250 Savage show a large increase in velocity for each percentage of increased capacity. But very large cases, like the long magnums, get much smaller increases in velocity for each percentage of increased capacity.

when I plug QL in with a 180TTSX with cart. length of 3.55 and with a 26" bbl using 71 grns of N560 gives same velocities as you mentioned but at 55442 psi. Using RL 22 at same charge is 57074 psi but both charges in the HH AI loads are 101 and 102% case fill. It does not according to QL range in the same pressures as the Weatherby at 65 g's.

edit: the 2 calibers in question the HH AI and Weatherby are definately 2 seperate and distinct animals. The Weatherby can run up to 3200fps with the 180 from the info I have, but the AI cannot. Unless you can compress alot of powder into its case.

I had found a list and even printed it out, but can not find it or the website. I'll keep looking.

Mr Ackley told me in a conversation I had with him in the early 70s while in Hawai`i that, although credited mostly for his 257 Roberts AI, that he always considered the 250 Ackley [250/3000] and the 7x57 AI his best. Of course that was back when we didn`t have the powder selections we have today OR the primers! So he is probably rolling around on his cloud wondering what he could have done with all the new goodies! Having had a 250 AI for over 25 years I can agree with him on this one!
Aloha, Mark

I have an older Savage 99 in .250 Savage with the 1:14 twist. Accuracy is OK with 100-grain bullets, but I would bet it would "sharpen up" with the chamber Ackleyed ...

I have a 25/35 AI, it sure kicks the shit out of the original version!

280AI is the only I have and have any experience with. I love it! Gets very near 7mm Rem Mag performance and you can buy brass for it. Great deer and elk round.

I can only tell you what I shoot and have owned so I would consider them good Ackley calibers. Right now I'm shooting a 35 WhelenAI,(2)280AI,
(2)6RemAI,243AI(2)223AI and 222AI. I've also shot the 7x57AI,22-250AI,30-06AI.

I've said this before when you build something you get to pick the parts and how that rifle performs is based on those parts. I know acouple guys who own Ackley rifles and their happy with the way they shoot more than velocity and that the way it should be. You build something for yourself when I build the first 280AI I think it was about 3 yrs before I ever chrono a load.

I don't have quickload or any ballistic software for that matter. i do know that my 280 rem while a great rifle can't hold the 280AI's jock. I have a lothar walter bbl and the 280 AI chambering shoots much flatter, yes more powder but the recoil seems identical. The same bbl shoots way better in 280AI. Is it inherent accuracy of a round or a better chambering job. I cant say but it works.

While most tend to think of getting magnum type velocities from non magnum case when talking about AI cartridges, as has already been mentioned, if your building the rifle from the ground up you can choose what the end result will hopefully be.

In my case, I had shot a standard 25-06 for over a decade and was for the most part tickled to death with the performance. I was not however too fond of trimming the cases back after every couple of loads. I decided to build an AI version but I had the heaviest bullets in mind when I did so. This said I figured on using the newer slower powders, coupled with a 28" 1-9 twist barrel to get the job done.

I had a decent supply of 120gr bullets as well as quite a few 125 and 130gr customs that were intended to be used, hence the faster twist. I wanted the added velocity, which was the choice for the longer barrel. Starting with RL-22 on the fast end of powders, I loaded several before settling on Ramshot Magnum, and getting just over 3300fps with the 120gr loads. When calculating the velocity over the standard round, this wasn't that big of an improvement since the added FPS came mostly from the added 4" of barrel. The same bullet was getting right at 3050 from the standard case in a 24" tube. What I DID gain over the original rifle, was <1/2 MOA accuracy out to 350yds, less trimming on the cases and the ability to shoot the 130's to just over 3000fps.

Was it worth it to build a custom rifle, to some not at all, but I simply love the .25 caliber and with the new rifle chambered in AI, it really brings those bigger bullets to life. It's also a darn cool looking round when all loaded up and ready to go. Now on the light end, with the 110gr AB, it ain't too far off the heals of a 22-250, but with a LOT more smack down. Talk about smoking a crow, it simply looks like you dumped a feather pillow into a box fan when you drop the hammer on one.

I have a 257 AI, a 25-06 AI, a 280 AI, a 30-06 AI, 338-06 AI, and a 375 H&H AI.

The 257 AI, 280 AI, and 375 H&H AI are real improvements. The 257 AI is essentially a 25-06 in performance. The 375 AI is a significant step up - I'm getting 2900 fps with 300 gr bullets, MRP powder, and a 26" barrel.

The 30-06 AI is only mildly improved, getting ~75 fps more than the std 06 when everything else is equal. It does allow one to use slower powders than the std '06. I recommend it; with re25, 69 grs, compressed, 180 accubond, 26" barrel, 3050 fps is easy with safe PSIs.

The 25-06 AI is well over bore, very hard on barrels, and not much of an improvement over the 257 AI or 25-06. I don't recommend the 25-06 AI, neither did Ackley.

In my opinion, the 280 AI is about perfect bore (given current powders) for the 7 mm caliber. I comes very close to 7mm Mag performance.

All have been very accurate and neck lengthening is stopped by the sharp shoulders.

I find that all primer pockets begin to loosen when you exceed 65,000 PSI, no matter the case design.

If you had a gun chambered with a 06 bolt, and you wanted to rebarrel to a more powerful cartridge (but keep you bolt and action), your best best would be the 338-o6 AI - your can get 225 gr bullets going 2850 fps with ~4000 ft# of energy with a 26" barrel. Either the 30-06 AI or 280 AI are improvements as well - they are twins in performance.

If you liked 25 caliber, going with 25-06 or 257 AI would yield equal results. The 257 AI is quite accurate and IMO perfect bore for the .25 caliber.

Do you think that a Ackley cartridge is any more accurate? Every Ack imp. rifle I have owned are very accurate. But bought them that way do not know how they shot before they were Improved.

Or is it just a better chamber?

quote:

The 25-06 AI is well over bore, very hard on barrels, and not much of an improvement over the 257 AI or 25-06. I don't recommend the 25-06 AI, neither did Ackley.

I can agree completely with the overbore part, and possibly the improvement part, but the barrel burning part I cannot in all honesty buy into.

There are many factors which contribute to a barrel heading south. Once upon a time the .220 Swift was considered to be a barrel burner as well. But with newer powders, better bullets, better cleaning compounds, things are much different today than they were 40 years ago.

Will I get 2500 rounds from my barrel, don't know, but if I DO toast the throat, I left plenty of meat on the shank to have it set back into a fine standard chambered 25-06. It's not like I built this one to sit out on a PD town and rock and roll several hundred round an hour through it. If I only put 20 or so a year down range, it should last me well past my time, and well into my grandsons.

quote:

Do you think that a Ackley cartridge is any more accurate? Every Ack imp. rifle I have owned are very accurate. But bought them that way do not know how they shot before they were Improved.

Or is it just a better chamber?

I think in some cases the changed case might help out with a better overall powder burn, which in turn might help bring a more shot to shot consistency. With some the neck tension might be improved a bit which might also help out. Chambering can go either way depending on the reamer and the fellow behind it.

I also have several barrels which are chambered in other AI calibers. They are all tack drivers, and most are after market factory produced, based on Contender frames. I cannot argue that the chambering has all to do with it based upon how these shoot, as I know they weren't tenderly reamed with the care given by a true gunsmith.

458 ackley
458 alaskan
22 hornet
30/300
with today's powders, the others are ho-hum and are merely loaded at higher pressures...

for example .. a 30-06 loaded with rel22 goes as fast or faster than "classic" 30-06 ai ..

100 fps is a nice round number for gain ... and top of the range.

have fun, but they are not with the trouble and expense... and devaluation of your rifle once its done.

I have a number of the AI versions - .257 AI, .25-06 AI, .280 AI, 30-06 AI, 338-06 AI, and 375 H&H AI. I've reloaded them all extensively for years and have tons of chronograph data, and also, I have comparative data with their standard precursors. On all, I’ve experimented with different bullet weights and most popular powders, from fast to slow-burning and all those in between.

It's true that the gain in case capacity is not always that great with some exceptions - that is, except the .257, .280, 25-06, and 375 where IMO there are significant increases in case capacity with the AI versions. But, IMO there may be other significant benefits from only mildly increased case capacity.

The secret is not just the increase in case capacity, but also using compressed slow-burning powder, such as Re25. The problem with using slow burning powder in limited case capacity cartridges, such as the '06, is that you can't get enough powder into the case, to bring up PSI to ~65,000, even with compression. In this situation, sometimes adding just a bit more case capacity (even as little as ~5%) will allow one to put enough slow burning powder into a case behind the right weight bullet to reach that 65,000 PSI, and this may take only a few additional grains.

This is the situation with the 30-06 AI. Using 180 bullets and the standard 30-06 with Re25 the maximum velocity with powder compression, which I was able achieve, was ~2825 fps, but using the AI version one can get ~71 grs into the case and achieve over 3000 fps – obviously those few extra grains optimized Re25 for the 30-06 AI. Using slower burning powders is a big part of the increased performance in magnum capacity cartridges.

Why only a few grains? IMO as PSI increases, powder tends to burn faster. Thus, there is a “sweet spot” for Re25 and 180 gr. bullets for the 30-06 AI that one can reach with only a 5% increase in case capacity.

If one wants more velocity, one needs to put more powder (energy) behind the bullet and bring the PSI up to maximum – stated differently maximum performance is achieved with the maximum amount of the slowest (high-energy) burning powder you can get into the case and achieve maximum PSI (65,000). You want to maximize the area under the pressure curve without exceeding maximum PSI.

The down side to maximum performance reloading is DON’T screw-up. Keep everything the same each time. Measure each powder change, shoot at the same ambient temperature, use a modern well-made and proven bolt-action rifle, use the same bullets, powder lot, case type, OAL, primer, etc. – clone your loads.

But, that said, slow-burning powders tend to be more forgiving than fast-burning powders and “soft” lead-based bullets are more forgiving that “hard” solid bullets or partition bullets. Exceed one of these variables and you might pop a primer – but don’t freak out, primer pockets may give way anytime you go over 65,000 PSI and first-rate modern bolt-action will not explode until you exceed 150,000 PSI. Always wear eye protection, the escaping gases from a popped primer could hurt your eyes.

Which AI modifications are the best? – answer, it depends. I like all of them except the 25-06 AI, which is way overbore. The standard 25-06 is overbore.

If you want to maximize your 30-06 action, I’d suggest going to the 338-06 AI. If you want more energy transferred to the bullet, use that largest available diameter caliber – remember, force = pressure x area.

But, larger diameter means lower ballistic coefficient and reduced down-range performance. But, Nosler now makes a FABULOUS bullet for the 338, the 225 gr. Accubond! It’s bonded, accurate, forgiving, and has a BC=0.55. If you can get this bullet moving, it’ll give accurate, long-range (400 yd plus), premium bullet performance. With the .338-06 AI and with a 26” barrel I’m getting 2875 fps with 63 grs of N204 (slightly faster burning that MRP). But, this is MAXIMUM – only work up to this load from below with a first-rate, modern (premium) bolt-action rifle. MRP was just too slow for the .338-06 AI with 225 ABs, so I went to the Norma powder slightly faster than MRP and was able achieve 65,000 PSI.

Regards, AIU

If we can accept what we have read it's hard to argue with the 250/3000AI as (at least) one of the best of the Ackley Improved cartridges.
A 10% increase in case capacity that yields a 17% veloscity gain seems pretty efficient to me.
Of course I suffer from a significant prejudice
when it comes to anything 257.
GOOD LUCK and GOOD SHOOTING!!!

quote:

Originally posted by the jigger:
If we can accept what we have read it's hard to argue with the 250/3000AI as (at least) one of the best of the Ackley Improved cartridges.
A 10% increase in case capacity that yields a 17% veloscity gain seems pretty efficient to me.
Of course I suffer from a significant prejudice
when it comes to anything 257.
GOOD LUCK and GOOD SHOOTING!!!

thats all pressure, not volume .. increasing a case 10% should result in about 2.5% increase in vel, at the same pressure
tanstaafl

quote:

thats all pressure, not volume

I don't mean to rain on anyones parade. I once believed all the AI press. I proceeded to build a number of AIs looking for the magic. Also built a number of Gibbs type wildcats. Testing each to my own parent handloads many in the same barrel. The high gains published were against factory ammo not hot loaded handloads. The largest gains from the AI were seen in the 250-3000 the 257 R and the 7x57. The max std pressures were around 53000, 51500 and 56500. Take those and then load them to just shy of brass failure like a normal wildcatter and see what up to 14,000psi gives you in gain. If you load each of those cases to max pressure you will be darn close to the AIs.

In an 06 case you will get around 1% velocity for 4% capacity in a tapered 7x57 based case the gain is a little more in the 308 based a little less.

What I found the reduced tapered AI case did was hide the pressure signs. I had a number of loads that showed NO sign and .5gr would blow the primer. AIs are normally loaded HOT. The majority of the gain is pressure related.

If you want an AI go for it. I still shoot many of my wildcats. Just be realistic in your expectations.

quote:

Originally posted by ramrod340:

quote:

thats all pressure, not volume

I don't mean to rain on anyones parade. I once believed all the AI press. I proceeded to build a number of AIs looking for the magic. Also built a number of Gibbs type wildcats. Testing each to my own parent handloads many in the same barrel. The high gains published were against factory ammo not hot loaded handloads. The largest gains from the AI were seen in the 250-3000 the 257 R and the 7x57. The max std pressures were around 53000, 51500 and 56500. Take those and then load them to just shy of brass failure like a normal wildcatter and see what up to 14,000psi gives you in gain. If you load each of those cases to max pressure you will be darn close to the AIs.

In an 06 case you will get around 1% velocity for 4% capacity in a tapered 7x57 based case the gain is a little more in the 308 based a little less.

What I found the reduced tapered AI case did was hide the pressure signs. I had a number of loads that showed NO sign and .5gr would blow the primer. AIS are normally loaded HOT. The majority of the gain is pressure related.

If you want an AI go for it. I still shoot many of my wildcats. Just be realistic in your expectations.

IMO Ramrod is AR's leading authority on the "AI" cartridges. He knows of what he types....

I've taken the liberty to re-post one of GSSPs posts regarding the 06 AI and using compressed Re25 with 180 gr. bullets. GSSP was able to exceed 3000 fps and closely approach 3100 fps, as I have done. Here is his post.

"The following is a set of reloading options and techniques which, take it or leave it, is outside the normal thinking when it comes to reloading. I was turned onto this idea by Ackley Improved User. As first, like many, I was skeptical and unbelieving. With an open mind, questions to the right people, research and actual testing, it worked for me. Your mileage may vary. (YMMV)

After more than 30 years of shooting the 30-06 in 22’ barrels, I wanted more velocity but without too much hassle or changing calibers. The 30-06 Ackley Improved seems the ticket for me! Since I was going to start with a new barrel (my Rem 700’s was shot out) and it is impossible to add barrel length, I started with a 26” stainless steel barrel by Dan Lilja of Plains, MT. It has a 1:11 twist, which Dan assures me, will handle up to 200 grain bullets and has 3-grooves instead of the more traditional 5 or 6 grooves.

I had Ian Jensen of American Fork, Utah, chamber, thread, crown and install my barrel into my 1982 Rem 700 long action, which had had a 22” 30-06 Mag-na-ported barrel. By the way, Ian is the gunsmith for Barnes Bullets! With that old 22” barrel, the fastest 180 grain load I ever put together was 2750 fps. It had worked for years on numerous elk, deer and antelope, but I wanted MORE!

The concept is to use more powder in the case. Gee, what’s so new about that? Well, the Ackley improvement adds a bit. My 30-06 Winchester cases add 4 grains of water after they had been fire formed to the Ackley. So, theirs a bit more powder! But then, many people have done the 30-06 Ackley improvement and not hit 3100 fps with 180 grain bullets in 26 barrels; have they?

The trick is slow powder, or should I say a powder which is slower than those traditionally used powders. Traditional powders like H414, W760 and WXR, the N560 series, the 4350s, Reloader 19 and 22, Ramshot Hunter, AA 3100, Norma MRP and the 4831 series. Don’t get me wrong, some of these powders are very good. Nosler notes how in the standard 30-06, 61 grains of Reloader 22 pushes a 180 grain bullet to 2872 fps and 62 grains of Reloader 22 pushes the same 180 grain bullet to 2985 fps in the Ackley Improved version; both in a 24” Lilja barrel with 1:10 twist. Makes me wonder if Lilja barrels are fast.

The powders I’m talking about are Reloader 25, Magnum, IMR 7828/ssc, H1000, N165, N170. Tradionally, these are magnum powders. Hey, if we’re talking about pushing a 180 bullet at 3000-3100 fps, we are talking magnum territory; albeit, the lower end of magnum territory.

I’m going to talk about Reloader 25 as this is the powder for my 06 Ackley. There is no loading data available for the 30-06 Ackley, at least none that I know of. AIU gave me a bunch of his data. I believe he derived it from Quick Load, and then tested it himself. From there, I tested some!

If you look in most reloading manuals, the traditionally slow powders are usually compressed loads. There are differing opinions on whether or not compression is good or bad. I’m not going into that here. The reloading manuals compress a little compared to what I’m going to talk about.

I’m talking about putting up to 70-71 grains of Reloader 25 into a 30-06 Ackley case; right up to the top of the neck. Again, I really balked at this in the beginning. I’d read an article by Rick Jamison in an early 2005 issue of Shooting Times. In it he brings to light the, then new, IMR 7828ssc. He says that if one wants to increase velocity, one needs to increase the powder charge weight. To do that the neat new thing about the super short cut version of IMR 7828 is that you get more into a case. He was able to get about 4 more grains of it into a 22-250 case. When used with heavy bullets the velocities can climb.
thought I! More powder gets more speed but what about all that compression and will it hurt something?

I called Hodgdon and talked to a tech. Without mentioning any cartridge specifics I asked some questions. I did this because I didn’t want any standard answers coming my way without him actually thinking about the question. I asked about the best way to increase velocity. Increase the powder charge was his response. I asked if the new shorter cut propellants allowed this. Yes he said. I then went on to ask about compressing powders and any inherent problems associated with it. He said the only problems he could think of, besides the naturally increased pressure issue surrounding powders which are quicker burning combined with the inherent danger of putting to much quick burning powder into a case, was the damage induced to the powder grain due to drastic compression. I asked what he meant by drastic compression. He said that when a person takes something akin to a wooden dowel and begins to bang and crush the powder to get it to compress, they can damage some grains, which can subsequently change the burn dynamics and alter the interior ballistics. I gave an example where I would slowly fill a case ½ way up the neck or all the way to the top of the neck, via slowly trickling through a long drop tube and use normal bullet seating, would that damage the grain structure. He thought for a moment and said “no, it should be fine.

The one problem I have encountered thus far while compressing the powder is accurate bullet seating to a specified OAL difficult. Added/decreased pressure from the seating stem/cup is needed and varies as powder increased/decreases.

I have run some 300 yd groups running in the 3-5 inch range. Heading out in the am, hopefully, to test some more Nosler 180 BT and Speer 180 Hot Core groups. I had to wait until I could buy some new bases/rings for my Nikon Buckmaster 4.5-14-40 w/ mildot and side focus. The old Conetrol rings and bases had the scope sitting 12-1/8 from the recoil pad and I was getting hit between the eyes. Great scope, just difficult to mount!"

I think many, if not all cartridges, would benefit from this approach. But, as I indicate in a prior post, apparently a little increase can mean a lot.

Regards, AIU

One can also fill a case 1/3 of the charge and compress it in a die (you have to make it yourself) with a brass rod.....fill another 1/3 of the charge and compress again and finally add the final 1/3 of the charge and install the bullet.

Start the load development with a magnum primer as you're going to light up a lot of compressed powder and work up 1/2 grain at a time......but of course, you don't need the "AI" version to do this......you can do it with the standard .30-06.

BTW, don't load a lot of them because if you don't like the accuracy you can't pull the bullets and dump out the powder.....you'll have to scratch it out with a pick!

As I've stated before, almost all cartridges could benefit (performance wise) from the compressed optimized slow-burning powder approach. Indeed, this appears to be the approach employed in the Hornady Light Magnum ammo, etc.

But, there are limits to how much powder you can compress into a case. Two things begin to happen, first the case itself expands and won't chamber and, second, the bullet will push back out, which can cause chambering and accuracy issues. In my and GSSPs experience this has not been a serious problem with Re25 and the '06 AI using 180 bullets.

Regards, AIU

I do not dispute anyone measured readings. I wasn't there. I share my info and mine alone. However, if someone is comparing a velocity of a std case in one barrel and an AI in a different barrel the data becomes suspect to me. Since I've had TWIN barrels chambers cut with the same reamer by the same smith same powder,same die same loader, same lot of cases vary by 100-150fps. Such is life. Each barrel is a test of its own.

I never tried compressed loads of RL25. I did try some heavy compressed loads of MRP2 (pretty much the same thing in my 340PDK. In my rifle once I went past about 110% compression my accuracy sucked. That could have been just my rifle.

I know this is only calculated data taking the 70grs of RL25 in a 30-06AI with a 180 and 26" I get 66896PSI 120% compression and 3113fps. Taking a 3006 case 68.32 gives me 66911 and 120% with a velocity of 3069 or a 1.4% gain.

Since these velocities are higher that could be barrel, chamber, powder burn rate or simply QL calculation error.

Maybe you guys have found the mother lode. To me unless the test were done in the same barrel the results don't tell me much. If you have no issue with that much compression and your accuracy is there then go for it.

I simply will not recommend someone go to 120% compression. Like I've said many times my opinion and a couple $$ will buy you a cup of coffee.

Ram,

Your QL calculations are roughly what we're seeing, but we're using Re25, which is doing the same (~3050-3100 fps) with likely a bit lower PSI (~65,000). All I could get with a std '06 using Re25 and a 24" barrel was 2825 fps, and I was compressing the crap out of 66-67 grs. beneath a 180 NBT. The barrel was a relatively "fast" barrel getting 2975 fps with a massive overload of W760 - a load that was not mine and one I recommended highly against using - but I was ignored. Sooner or later, some primers are going to be popping out of those cases.

Regards, AIU

AIU
My fingers got ahead of my brain. I ran the numbers with RL25 just typed 22. I had also ran the numbers using a flat based bullet and 3.34OAL. Switching to a BT and slowing the burn rate to get the results in the 3100 rnage the pressure is 68,098 and 127% fill. Using the same info for a 06 with 66grs gives me right at 60000 and 2870fps with 123%.

These numbers seem in the ballpark using the posted capacities in QL along with the 3.34".

As I stated I think when we had the same discussion over a 338-06 months ago if they work for you go for it.

The few times I tried that much compression my accuracy sucked. That is one data point. When I can get it MRP at slight compressed load allows me to get the velocity I want. It has matched within a couple percent of QL calculations in my testing. Those same calculations say a mild compressed MRP load will out perform a 127% compressed RL25 in both a 30-06 and 30-06AI.

As I have said I have minimal super compressed load data. I've always been able to get the velocity goals I wanted with slightly faster powder and less compression. To me far less headaches.

I used to destroy a lot of brass in my testing. Now I've got to the point if a nice safe load leaves me 50fps shy of my goal and it is a must have I grab a larger case.

I'm glad the heavy compression works for you it is no my cup of tea.

Ram,

I used to be a big fan of QL, but then I learned of the mystical QL fudge factor - the "weighting factor" I think it's called. This poorly explained "factor" is supposed to be a under/over bore correction for unburned powder consummed in the bore during detonation???

I know you know about this. Play with it and you can get almost whatever results you want out of QL. Besides, do we know in the QL program how this mystical "factor" might change with PSI or the burn rate of the powder being used - it could vary a lot.

However, I still believe in the basic principle:

That the maximun amount of the slowest burning, high-energy powder you can get into case behind the desired bullet and achieve (but not exceed) the desired maximum PSI will produce MAXIMUM velocity.

This principle is repeatedly illustrated in the QL program and being used by others, such as Hornady with their Light Magnum Ammo. I'm willing to take my high-performance loads to 65,000 PSI, just below the point when "accelerted" primer pocket (case) failure begins to occur.

Regards, AIU

I like QL. Compared to results I had with Loadtech I find QL to be light years closer. Is it perfect nope. Just like no two rifles will give you the same velocity. I'm sure QL has more fudge factors than we know about.

What I have found is if I take one of my rifles and load data. Fire it and get a Chrono velocity and then tweek the burn rate in QL I can then use that new burn rate in all my other rifles using the same powder and lott and get real darn close velocities.

I simply use QL as another DATA POINT that allows me to tweek for capacity OAL and improved burn rate.

If we all skinned the cat the same way just think how boring it would be.

Paul, what I find amazing is that we've been discussing here some really advanced, sophisticated, and high-powered reloading techniques, but not many folks seem to be that interested. Yet, it would seem very useful to serious reloaders. Any explanation? Regards, AIU

quote:

Originally posted by kk alaska:
Do you think that a Ackley cartridge is any more accurate? Every Ack imp. rifle I have owned are very accurate. But bought them that way do not know how they shot before they were Improved.

Or is it just a better chamber?

Besides the AI I own I have custos in standard calibers and those are equally as accurate as the AI.

Trick is you need a good gunsmith.

quote:

Originally posted by Ackley Improved User:
Paul, what I find amazing is that we've been discussing here some really advanced, sophisticated, and high-powered reloading techniques, but not many folks seem to be that interested. Yet, it would seem very useful to serious reloaders. Any explanation? Regards, AIU

AIU,

I've never used QL and I'm not sure how accurate that is to a custom Ackley. I'm not sure if one can put in barrel length,type primers,type rifling and twist type bullets how many grooves etc to get a real world velocity.

I've seen as much as 100fps with different bullets with published data for the AI and appr 50fps changing from standard to mag primers. We all know throating can cause increase in velocity and adjusting neck tension as well.

AIU, I think some just get tired of of the P*****G contest when the subject of velocity/pressure comes up. I do.

quote:

Do you think that a Ackley cartridge is any more accurate?

IN testing I had several STD barrels that I simply ran an AI reamer in. Yes the headspace would have been a touch long but I was trying to determine velocity gain. I never saw a major difference in the before and after accuracy.