Got a question for you guys here....

Just how much improvement will I get from my 22-250 if I make it
an ackley improved cartridge???

Is it REALLY worth the effort to do this or should I say the **** with
it and leave it alone...Be honest with me now....Thanks guys..

By the time you have your barrel re-chambered, pay the cost for a set of dies and go to all the time and trouble to build loads for it your going to gain a hundred to hundred twenty five feet per second. Also when you go to sell or trade that rifle off you've devalued it a bunch.

I'd stay with the standard cartridge, but that's just me.

Kind of the way I was thinking anyway..I have been hearing that it is a big improvement
and all that..Thanks so much for your reply.....

.....that with the .22-250AI you will get about the LEAST improvement(velocity) of most of the AI's.

With the added powder burn you would be even more overbore. The extra powder for the extra velocity would make the chambering not worth it(IMO).

You bbl would got to heck and as stated the value of your weapon would decrease by 200(or so) bucks.

I would also agree with (maybe) 100fps over the origional.

IMO,not worth it. -----pruhdlr

I've written this before, but most modern rounds are ALREADY semi-Ackleyed. The rounds he got the most success and "improvement" with (25-35, 30-30, 30-40, 250 Savage) had highly tapered cases, sloping shoulders and long necks. Noting that, cartridge designers began shortening necks, steepening shoulders and reducing body taper. In short, semi-Ackley, right from the box. There simply isn't much room for new so-called improvement - and even less added results to expect from it.

The general "1/4" rule applies: you'll get about one fourth the percent of velocity change as percent of case volume change. Make the case eight percent larger by volume and you'll get about two percent added velocity. If your round already gets 3800 fps, that's an added 76 fps (if the volume change is eight percent). Whoopee.

People who claim to get hundreds of feet per second are simply running the thing at MUCH higher pressures than the regular round. And if they are willing to run that pressure, they could have gotten the same added speed from the regular round loaded extra hot.

Had one years ago in a thin barreled M77 Ruger (why it came from the factory with such a barrel is a mystery to me). Found the case life was greatly extended and accuracy improved nicely. Never tried to hot rod the cartridge - was just satisfied with the fine accuracy.

Fellow co-worker lusted for it - had a Redfield 6-18x44 rangefinding scope and a Harris bi-pod. Told him you could only fire a few rounds and then had to let the barrel cool, but he still insisted with the cash to back it up. He and his brother used it for antelope and thought it was the perfect fit. Wonder where it ever ended up?

I remember an article on the .22-250 Ack Imp by Ross Seyfried a number of years ago. He used it because he was able to hit coyotes at 500yards with the standard .22-250 Rem with a 55gr Nosler Ballistic Tip but the bullet wasn't opening up fast enough at 500yards to ensure he recovered the animal, but it was completely reliable at 400 yards.

He went to the .22-250 Ack Imp to get the same downrange velocity at 500yards that he got at 400yards with the standard .22-250 Rem. So, if you need to anchor larger varmints at 500yards then do the conversion but otherwise, stick to the original.

Another option is to with a 220Swift.Mr. Ackley states in his book that ballistics are the same for borh cartridges.

i thought i read somwhere (6mm benchrest i think) that the AI on th e.243 helped a lot on case stretching. and for the target shooters was the real reason for going AI on the .243. i was under the impression so i'm kinda asking this not as much as stateing this, that there are several factory rounds where case stretching seems to be more of an issue and that issue is helped quite a bit by going AI, is this true?

Cases that have a long taper and not much angle to the shoulder (300 H&H comes to mind, along with the 22 Hornet) benefit the most with improving. Cases that have slight taper and a shoulder of 20 degrees or more benefit the least.

Yes, improving helps in reducing the stretch factor because you have more shoulder to retard it. Rimmed cases that are improved will begin to headspace on the shoulder rather than the rim and this also restricts case stretch. In addition, any case that is rimmed or belted for headspacing leave the front of the cartridge to sorta just hang in the chamber without regard to chamber axis. Improving such cases have alignment both front and back which greatly enhance alignment.

Things that most AI cartridges do.

#1 added case capacity
#2 decrease bolt thrust allowing higher pressures
#3 added case life
#4 more controlled burn adding efficiency and accuracy
#5 bragging rights at the range

The 22-250AI was used a lot by benchresters as was it's parent 250-3000AI
reason mostly that controlled burn but also a good deal of bench shooters when making brass for event shooting, go to great troubles matching their brass, wish for it to last as long as possible.

Things that most AI cartridges do.

#2 decrease bolt thrust allowing higher pressures


Maximum pressures are determined by the strength of the materials involved in containing the pressure, I think.

Could you explain how enlarging the chamber and reforming the brass increases the strength of the materials?

Thanks.

--Bob

Bob the strength of the matierials is there in most bolt guns, with a wide margin. Once in a while you have the bolt lugs come loose during an extreme overload or bad manufacture. The decreased bolt thrust comes because of the reduced taper of the straighter walled case on the AI version. I have seen a 30-30 AI using a colt style hammer with firing pin no bolt to lock it in fire with a full load leaving the case in the bbls chamber. With the standard 30-30 and the same setup sent the case through a chrony at over 2000 fps. To say the least, I was impressed at the reduced bolt thust of the AI version. If the max pressure of a cartridge is 35,000 because of a mechanical lockup, ie a lever gun. You are lessening the mechanical pressure by going AI, hope I have explained well enough. So I reckon, I stepped on it by my statement.

On page 282 of Parker O Ackley's "Handbook for Shooters and Reloaders", the writer states; " Two versions of the Improved .22/250 are illustrated. One has the less radical 28 degree shoulder like the regular version of the .22/250 or .22 Varminter. The other has the more radical slightly venturified 40 degree shoulder. Both are very good cartridges and both use standard .220 Swift loading data giving practical identical ballistics. There is little choice between the two shoulder angles or any in between. Such a choice is always influenced by the shooters own ideas and preferences. The cases are made by necking .250/3000 Savage brass down to .22 then firing it in the improved chamber to fire form. Good stiff loads are best for fireforming. Very few or no cases are lost in the fire forming step. The minimum body taper and sharp shoulder angle minimize the forward flow of brass or lengthening of the cases to the extent that case trimming is rarely necessary. Use standard Swift loading data. Standard twist: 14".

One must be careful to take the above statement in context. Ackley wrote this in 1962, before the .22-250 had become a factory cartridge. Anyone who wanted a .22-250 in those days was dealing with a wildcat cartridge that not only required special dies, but also a gunsmith to rebarrel or rechamber a rifle. Given this fact, a shooter could choose which version of the wildcat .22-250 he wanted with little cost difference between the choices.

It could very well be, in later magazine articles, Ackley may have changed his mind somewhat after the .22-250 had become a factory cartridge, and the choice between a standard cartridge vs a wildcat involved a whole new set of considerations. None-the-less, his 1962 statement about various wildcat .22-250's would still hold true.

Swany, you say that reduced backpressure allows us to load to higher pressure, and also say that there is a wide margin of strength in bolt guns.

Can you tell me how strong the backthrust is? How much extra pressure one can load to? How deep the strength margin is and how far we can edge into it? Can you tell us EXACTLY? And if so, based on what specific knowledge?

For years and years some gun writers have often refered to bolt thrust, and how tapered cases have more thrust than straight wall cases. Frankly, I have never seen, or heard of, any testing that offers proof that this statement is in fact true. Closely associated is the theory that tapered cases "flow forward" during firing and thus don't last as long as straighter walled cases. Even Ackley said this, although he never offered any technical proof.

I have found that my 300 H&H cases, which are quite tapered, last just as long as my 270 Wby Mag cases when I neck size only. As far as bolt thrust is concerned, I don't see any more bolt face markings on the head of the 300 than on the 270, and both cases have identical heads and are fired in very similar model 70's.

Bullet-Maker, if you want more velocity, I suggest going to the Ruger 204 or the .17 caliber. Now buy the time you invest all that money, for what is going to be needed on your present 22-250 rifle, you could almost purchase a new rifle or close to it.

I purchased a 22-250 a few months back after getting a CZ rifle in the .222 caliber. My wife liked it a lot, so she put her name on that rifle. I finally went and got a caliber I had years ago, (Remington model 788 in 22-250) just wish I had not waited so long to do so.

I hand load this new rifle down a bit from factory loads! I have it pushing 55 gr. pill out the barrel at a megar 3300fps. Plenty fast enough for this coyote hunter and I betcha the barrel will last a lot longer to boot.:D

I have 22-250 AI in an accurized Rem. 700 BDL with a Hart match 27" bbl. This is meant to be a live varmint rifle where accuracy and flatter trajectory are appreciated. I previously owned a Ruger 77 with a 24" varmint bbl. The fastest safe and accurate load for the standard 22-250 chronoed at 3400 f/s out of that 24" bbl. The 27" Hart bbl. chronos at 3800 f/s with no high pressure signs with the best safe and accurate load . The extra 3" and the smoother Hart match bbl. may account for some of that extra 400 f/s. These loads are with 55 gr. bullets, Nosler Solid Base in the standard 22-250 and Sierra flat base spitzers in the AI.

I would guess that 75-100 f/s is gained by the longer and smoother bbl. but that still leaves 300f/s gained with the AI chamber. I hope that this might give some insight as to what may be gained with the AI chamber. At least, this is how it turned out for me.

Rev

One of the key facts in your post, Rev, is the statement of the quality barrel with smoothed bore. Lots of folks fail to realize you aren't going to gain a bunch of velocity without undue pressure in barrels that are short with rough interiors.

With my AI's, all have usually demonstrated a 4% to 5% increase in velocity with a corresponding 4% to 5% increase in powder charge. The main reason I go to the AI chambering is to ease the case stress to increase case longevity.

If you are doing a re-barrel project anyway I'd say go for it. You may only gain 100-150 fps but, at least with mine, I can shoot standard fare 22-250 rds. with no loss in accuracy, I get the 125 fps gain, , don't have to trim every 3-4 loadings, case life is great and besides all that they look cool.

As you pointed out so astutely kdub, there is really no way to tell how much of that velocity gain came from the AI chamber, the extra 3" of bbl., or the increased quality of the match bbl. Another variable that I failed to mention is that the AI chamber is with a .246" tight neck. That helps maybe in bullet alignment, but probably not velocity.

Rev

Those kind of things are learned by doing and having done them and seen with your own eyes, not every thing is written in a book and if it was there are still some that couldn't understand it. Bobby
I needed to add that I have built up several of the 22-250 AI for some guys that go for the furs here, good long range and accurate. I have one pictured on my flickr page. www.flickr.com (http://www.flickr.com) for
padiegdoc

Those kind of things are learned by doing and having done them and seen with your own eyes, not every thing is written in a book and if it was there are still some that couldn't understand it. Bobby
I needed to add that I have built up several of the 22-250 AI for some guys that go for the furs here, good long range and accurate. I have one pictured on my flickr page. www.flickr.com (http://www.flickr.com) for
padiegdoc

I agree Bobby, that "many things are learned by doing". But I don't see how any amount of "doing" is going to allow someone to predict how much of the total amount of velocity gain will result specifically from (1.) 3" of bbl., (2.) an A.I. chamber, or (3.) from a better (Hart "match", in my case} bbl. Don't mean to nit pick here, but all of these afore mentioned improvements will help some velocity wise as we all know. How much? Anybody's guess is what I believe, (no matter his experience.;)

Rev

Yup - each rifle is a law unto itself.

Think it's safe to say, AI'ing a "standard" cartridge will help in increasing case capacity and with the sharper shoulder, help in longer case life.

The bugaboo is just how much it will benefit that certain rifle over existing values. I agree you can't use a yard stick and say it will definitely increase velocity and accuracy by such and such. You'll just have to determine that on a case by case result (no pun intended, really!).

Rev. I spent at lot of time with this old gunsmith, he lived in Anchorage, I live in Wasilla about 50 miles away. I would go in and spend friday night with him and would work with him Sat., sun., and monday. We had alot of time togeather and I would spent as much time as possible picking his brain on every thing that I had questions about. He wrote a book called Advanced Rebarreling of The Sporting Rifle by Willis H. Fowler,Jr. What he like to do was rebarreling, muzzel brakes, and any thing related to that. He didn't like repair work much and stayed away for that end of the trade. He designed his own muzzel brakes and spent alot of time testing them with all differnt calibers and barrel lenghts and loads to try to firure what worked best. With all that testing he learned some things about what would happen with his test guns, loads and muzzel brakes. Different loads, barrel lengths, barrel diamenters, muzzel brakes and there effects on accurcy and in velocity. He told me one time when we were talking about brakes that some times when he had added a muzzel brake to a rifle and re-test fired it that it would raise the ponit of impact out at the same yrds with the same loads some times as much as 8" and you would alwasy get increased velocity by a few ft. pre. sec., 25-40 or more depending on the bullet weight, style, manifacture, or caliber, but he couldn,t really say exactly what would cause the effect, he just new it would happen some times. Nothing was always exactly the same from gun to gun and cal. to cal., too many varables. This is just one of things that isn,t in a book, you can't make a table out of it and you just have to learn them by having done it. I have found that to be so true in this kind of work, and the more I do and the more I learn, the more I know there is a lot more I haven't learned yet and don't think will ever know. Can't tell you how much pressure one action will take because it will not fail exactly from the same things or time. I read a book Called Hatchers Notebook, by Julian S. Hatcher Major General, U. S. A. retired. In this book this guy sent his entire career in charge of the Experimental Department of Ordnance and other Departments in this field, his book is written from his notes on his experiments of every fire arm in the military. Every kind of thing that you could think of to do with a fire arm he just about tried. Example, tested an o3a3 by test firing it with the barrel filled with cosmoline, one failed and blew up the barrel, another did not fail. Why? your guess is a good as mine, he just knew some would, and some wouldn't. Some of the low number springfield recivers from the springfield armory had heat treating problems, some would fail in just a few rounds having been fired in them and others didn't fail at thousands of firings, but all would most likely fail at some time. Like you said how much is any bodys guess, but you can have some idea of what to expect, like if I do every thing perfectly to build up a firearm, It should shoot very well, but it will still only shoot as good as the barrel will or how good the shooter is or how good are his loads and how much experemiting he puts in finding that "sweet spot" in his firearm or a dozen other things. That is what makes all this so much Funnnn. Bobby









dep

I agree almost totally with what you say Bobby. When I had my .22-250 AI built, I wanted max velocity and best accuracy from a live varmint rifle. I do not shoot competitively, and so have no wt. restrictions. I knew that in a 'blueprinted" Rem. 700 action with a bench rest contour 27" Hart match bbl., that I would get some gains in both accuracy and velocity. Did I know how much from each variation from the norm? No, I did not. But I was certain that I would get something from each one.

Ackley said I should expect .220 Swift performance. He had a lot of experience similar to what your gunsmith mentor had. Guess what? That performance was exactly what I got. 3800 + f/s with a 55 gr Sierra flat base spitzer and all in a safe load.

My accuracy gunsmith is a bench rest competitor. He knows what it takes to get really good accuracy. I do listen to what he tells me. In this particular rifle, we went with a "tight neck". A .246" neck in that .22-250 AI chamber. We did have to get a custom reamer made. I think we all are aware of the advantages/ disadvantages of that. The rifle will shoot 1/4" to 1/2" groups at 100 yds. The 1/2" groups are always my fault.

What bothers me some in previous posts from some gunsmiths, is that they would not chamber a bbl. that does not conform to SAMMI specs. That means that I would never have gotten my tight neck chamber from them. It's true, of course, that my rifle will not chamber any new unfired 22-250 case or any factory .22-250 cartridge. At least not until I very carefully turn that neck to get a .244-.245" OD neck in the reloaded round.

I can appreciate that not every gunsmith is interested in this type of work. My guy doesn't do any stock work and no rebluing. He only produces bench rest quality barreled actions. Each gunsmith does what he is comfortable with doing, and I certainly understand that. I think what I don't like is the kind of arrogant attitude, " I know what's best, so take it or leave it".

Don't get me wrong here. I admire the abilities of gunsmiths as a whole. I've never gotten a poor job from any gunsmith. It's just the "I know it all, and you don't know much" attitude that bugs me.

Rev

I get 250+ over standard 22-250 with my AI. However I'm also being told with less then 600 rnds through it I have BBL erosion. However I'm still getting great accuracy. On my way up to range now.