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Roger, The rating just appeared.....I have no clue where it came from.....as to who won????? I never had any intention that there'd be winners or loosers when I started this.....It just seemed to be a good issue to debate in the open.....winners include anyone that learned anything.....in that light one is me!!!! As to "pepper to fly shit" I think the other 5-star thread wins that award hands down.....Scott started it by (essentially) asking how to rebarrel his M-1 Garand to 6.5-06 or .280 Remington. I think it was answered in two or three posts.....in stead it carried on for 13 pages and 121 posts.....most of which was unrelated to the initial issue. It reminds me of the old cliche.....I asked them what time it was.....they told me how to build a watch!! I am a little saddened that Mr. P. O. Ackley wasn't present to post his own attitudes on the subject.....but we all have that appointment.....and his is historic. Again.....depending on what one is willing to learn (and velocity gains in improved cases is only one small part of this) there's a lot of education to be gleaned from this or any other topic on this board. If one isn't learning anything, maybe it's time to do something else with his time!!! | ||
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I have thought about AI before and have comeup with this thought: A. With most you only get about 100fps or so. What's the point? B. Many cartridges are offered in High/energy/light/mag which usually beats AI. practice with H/L, hunt with those. C. Many big gains are due to 'pressure pushers'. D. If you ever sell, you'll almost never get your money back Just my $.02 capt david  | |||
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my understanding of the AI concept after reading Ackleys two book set is to make the best case design to allow higher pressure to achieve higher velocity while not putting more backthrust on the action.the minimum case taper with sharp shoulder is the way to achieve it.Some cases are already over bore capacity and dont benefit much from improving,however if you shorten the case and give it an improved shape,you can often equal velocity with less powder.ackley noted the 257 roberts improved was probably one of the best examples of the improved design. | |||
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.....but the first one to say that the "improved cartridges weren't really improvements was Ass_Clown..... Hey, I was the first to reply to your question and thought that I was agreeing with you that they weren't too much of an improvement.  | |||
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Vapodog, Get a copy of Art Alphins reloading manual, "Any Shot You Want." He has data for the 375 H and H, 375 Weatherby and 375 JRS. I can beat these by about 100 fps by using WW brass. His pressure data certainly proves you can "improve" the standard .375 H and H by blowing out the case and using a slower powder. If you dont want to spend $30 for the manual here is a short course: 375 h and h 53,000 cup, 62,000 piezo psi, 2,550 fps 375 JRS, 53,000 and 63,800 piezo, 2,710 fps 375 weatherby, 55,152 cup, 63,861 piezo, 2,700 fps. He might have some other "improved" ctgs in the book for you to look at. All of these loads were what he used in his factory ammunition using A-Square brass. The 375 and 375 JRS used the 300 grain monolithic solid and the weatherby the dead tough soft point. All from 26 inch pressure barrels. The pressures were maximum average. He also indicates the maximum indicated, SD and ES. Andy | |||
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Let me reproduce word for word from Hornady's 1973 handbook on the .30-06 improved: BUT OUR .30-06 IMPROVED DID NOT LIVE UP TO BETTER PERFORMANCE EXPECTATIONS; IT ONLY SUCCEEDED IN USING MORE POWDER TO ACHIEVE THE SAME VELOCITIES ACHIEVABLE WITH THE STANDARD .30-06 BTW I thought this book would have .375 Weatherby data but the .378 Weatherby was alrerady out and the .375 Weatherby was history..... | |||
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Sarge, If all you want is 2550 - 2,600 fps with the 375 you can load the improved cartridges down to a pezio pressure of only 45,000 - 50,000 psi. This is 13,000 - 18,000 psi less than a standard 375 H and H at the same velocity. Dont take my word on it, look up Alphins data in the A Square manual. Vapodog, you will be glad to see that Alphin shows only an 80 fps increase in velocity over the 300 winchester with the weatherby. You can get that just by seating the winchester out to 3.55 and cutting the throat of your barrel to accept the longer ctg as 1,000 yard shooters have been doing for the last 30 years. Are there any other "exceptions" out there??? Andy | |||
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Quote: That's the comment I'm replying to.... Now Andy Thanks for that bit of help.....I couldn't find the Weatherby data and like the .300 H&H compared to the .300 Weatherby the improved case is "SIGNIFICANTLY" improved. This too with the .375 H&H compared to the .375 Weatherby.....But this merely makes the point about improved cases.....these examples are true exceptions. In my examples I compared standard rounds to their magnum counterparts and only found small increases in performance. What makes folks think then that a (for example) a .30-06 improved is vastly superior to a standard .30-06 when the .300 H&H isn't vastly superior to the standard .30-06.....etc..... Why would one think a 6.5-06 improved was vastly superior to a standard 6.5-06 when the .264 Win Mag isn't vastly superior to the standard 6.5-06??? I fully agree that weatherby's .375 and .300 magnums are better than their H&H counterparts..... | |||
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Another "Exception." I just checked the nosler reloading manual for the data on 22-250 and 22-250 improved. the improved has a 240 fps advantage over the std case if you look at the most accurate load tested data. Just a 100 fps adv if you look just at fastest powders for each. If you are trying to hit a ground hog in the head at 300 yards in a 10 mph full deflection cross wind, like I am, youll take the improved ctg every time. Frank Glenn, the many time Bianchi cup champ made a 22-250 improved for me some years ago, well before the nosler manual came out, and I took it on his advice that this was a great ctg. Well, turns out, it is! Add this to the list of truly improved cartridges. Andy | |||
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Is it a bit of a red herring to compare "standard" and "improved" cartridges at the same pressure levels? In my conversations with father Ackley back in the late 50s, early 60's, one of his objectives as stated by him was developing cartridge shapes which allowed him to run higher maximum pressures while still adequately supporting the brass and having it extract more easily...i.e., without markedly increased bolt face pressures. He was trying to find a way to safely run HIGHER pressures without paying too high a cost. Another objective was increased brass life, which does seem to be a benefit (improvement) wrought by the less tapered cases with sharper shoulders, over the more tapered, shallower shouldered "original" configurations of the unimproved factory renditions of the cartridges of the day. Yet another goal was the ability to use larger amounts of slower burning powders than were currently the vogue, so that more energy was released behind the bullet without too great an increase in peak pressures....more high pressure duration under the burn curve, which must almost always improve performance. There are, of course, some down sides to this re-shaping. For one, though the cases often extract better, they sometimes are harder to make feed as easily INTO the chamber because of the lack of taper and the sharp. crunchy shoulder. With some brass, there is also a fairly high loss of cases during the fireforming process. A particularly bad example of that was the re-forming of .219 Zipper cases to Improved Zipper, when using the brass available for the 20 years immediately following the WWII kerfluffle. Pre-war brass had more copper in it and formed very well. Post-war brass was much more like today's and would split at the shoulder/neck juncture almost every round. There were several possible answers to that problem...one of which was to buy RCBS form dies and make the brass from .25-35 or .30-30 brass. Another, of course, was to do a satisfactory job of annealing standard factory brass before loading it for fireforming. Anyway, I think some of the "improved" cases were fairly successful...the .22 Hornet, .219 Zipper, .25-35 Winnie, .30-30, and .257 Roberts were all cartridges I liked better in "improved" wildcat form. I DO agree with you on "improving" the biggest boomers. If the .460 WBY won't do it, go to a .475 A&M...or call in close air support!! <G> Alberta Canuck | |||
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Quote: Mr. Ackley had done a lot of rifle testing and is known for testing to failure many of the bolt action rifles of the day.....which BTW are (nearly) the same as available today... and he knew well that the weak link in the system wasn't the strength of the actions but the brass cartridge case. He was also sharp enough to know that a higher chamber pressure would be a direct increase in bolt face thrust regardless of the geometry of the case. Quote: You are not the first to make that claim and there's reason to support that statement. I've often wondered however how much of the increased case life was the result of the expert smithing done to the chambers and the extra care given the finnicky reloaders of their cartridge??? Quote: My examples of the performance gains of magnum cartridges compared to their standard counterparts is a clear indication that very large increases of powder capacity is necessary for only a small increase in velocity. This claim just isn't supportable given the traditional body taper and shoulder angle changes of AI designs. | |||
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I don't own a mag improved but some may have one done up but I do own afew in 22 and 6mm and the velcoity gain and case life is worth it to me. I use in-line dies and very little case trimming and I've gone some time up to 10 firing before have to push the shoulders back some. | |||
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vapodog, Quote: Well, DUH! ASS_CLOWN | |||
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I shoot the 250 Sav. Ack Imp and have for over twenty years now. The real improvement that I can see is that cases last virtually forever. I hate trimming cases!!!I make mine from Lake City NM cases. I use form dies from CH4D and make standard 250 Sav. cases, fireform in the imp chamber and then load as usual. I get over twenty loadings and they do NOT grow like the standard cases and accuracy is fine. Another Ackley design I shoot a lot is my 260 AAR. It is made with NM 30-06 cases. The powder charge is less by a grain or two in both cases but is more than made up for in case longevity and accuracy. I just acquired a nice 700 BDL in 22-250 and you can guess what will happen if the barrel shoots. Set it back .009 and make a 40 Deg shoulder on this one too. Make the cases from LC N.M. 308 cases and shoot to my hearts content. Aloha, Mark | |||
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vapodog, I wasn't being nasty, just a smart ass! I guess I should have included a smiley face or something! Besides that with such an "ASS_CLOWN" reply I figured I could get the pot stirred up for ya!  Party on!! ASS_CLOWN | |||
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Quote: From Nosler #5 and the 50 gr bullet the spread between the standard cartridge and the so called improved version is 54 fps for the highest velocity. The 55 gr bullet's spread is 53 fps and the 60 gr spread is 35 fps. Also note that the blown out version had a 2" longer barrel! In the same manual the Swift beats any Varminter easily with all bullets. I have three rifles with improved chambers. The one on a rimless cartidge is easy to live with and was fun for a moment. It's no improvement however unless 60 fps matters. The one on a belted case, the 375 Improved, is an abomination and separates the case at the expansion web in a few shots. | |||
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vapodog, Ackley's "obsession" with bolt thrust has always interested me. With any of the Mauser derived bolt actions, bolt thrust isn't the primary failure mode of the action, not even close! I sincerely believed that Ackley observed this and understood that the brass, which is the primary system failure mode, would not begin to fail until > 70 ksi and just concocted a way to dump a few more grains into a case and get the pressure up to 65ksi - 67ksi and show a modest improvement in ballistics over the same parent case loaded to a mere 55 ksi - 60 ksi. It has provided him at least some form of interim immortality, as his contributions get argued back and forth between the reloaders ALL the time. To me the biggest question is: Is a Ackely Improved 45-70, loaded with Sierra MatchKings the Ultimate Dangerous Game Load or what? ASS_CLOWN | |||
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Quote: Herein lies the real truth on "improved" cases!!! ass_clown quote: Quote: You're one sick man!!!!! | |||
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Even assuming that there are "I" cartridges that can achieve 200 fps over the stock version, I fail to see any point. The only thing that, IMO, you get from velocity beyond around 2500 fps, is a few yards more point blank range. Now I may be aging and arthritic but that doesn't keep me from crawling a couple of hundred feet to get a closer shot. In fact, I like it. Don't anyone go off on energy levers, either, because the only thing you can certainly say about "energy" is that it is easy to calculate. Hydrostatic shock? Puh-leze! Ackley was of a generation that believed in such things. Hopefully, by now we have come to our senses. In short, no, AI cartridges are no improvement. | |||
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Vapodog, I own 6 rifles chambered in Ackley Improved cartridges and I see a marked improvement in all of them over the parent cartridge, as measured by Oehler. Never lost a case fireforming and damn few since. The arguement about reduced bolt thrust is very real. In the R&D days with my 1st Ackley Improved, I got a little carried away tipping the can, charging with a drop tube sometimes, and no matter how hot the load the bolt still opened with ease. Now I don't have an engineering degree or pressure barrels but from what I have experienced over the last 35 years or so i'm not about to change. You forgot to mention the passage from St. Parkers bible, where he nearly equaled the velocity of the .257 Weatherby with a .257 Ackley Improved, with 17grs. less powder. Same barrel used for both. I'm not going to change your mind and you're not going to change mine. Stepchild | |||
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The problem here is largely that we are not comparing today's cartridges with yesterday's, when we talk about "standard" cartridges from today's factories. Yesterday's cartridges often could benefit from some ballistic "improving" while most of today's do not. Many of today's cartridges ARE larger capacity, to enable use of burning slower powders, to get more total pressure (not necessarily much higher pressures, but longer duration) under the burn curve. Also, many of today's cartridge cases are shaped similar to Ackley's improvements of the cartridges of that contemporay day. To that extent, the modern cartridges are current justification of Ackley's and other wildcatters' design thoughts. If you think that cartridge burn efficiency (fps per unit of powder) is a valid criticism of Ackley's work, then you must apply it to all modern large cartridges as well. There is no doubt, for instance, that a 7m/m Rem Mag burns a great deal more powder than a 7x57 to get its increases in velocities with like weight bullets. Does that make it a "bad" or "not worthwhile" cartridge? There are sure a lot of gun buyers who don't think so. Their objectives are flatter trajectory and maybe harder hitting, not powder burn efficiency. Personally, I tend to side with you on the cartridges I prefer. Most of the time, I like the unimproved, mild cartridges, such as the .25-35, the 7x57, the 8x57 and 9x57. However when I was doing elk control shooting at distances and numbers of animals that were NOT sporting, I grabbed the .300 Wby as often as not. Made it easier to sleep at night. Best wishes, Alberta Canuck N.B., thanks for the URL, great stuff there...!! | |||
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Digital Dan, Your correct and I may have misinterpreted Saeed's post. I am not going to look at the rifle right now as I need to add some wood to the fire. I will keep the thought in mind however. It's true that any chamber that's large in diameter will pull metal. | |||
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Quote: Only for shots exceeding 600 yards. Jeff | |||
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