I was recently talked out of converting my 257 Roberts to the improved. I was told that I could nearly duplicate the velocity with proper reloading. So now I'm wondering, are any of the "improved" cartridges worth the monetary investment?
There's a lot of posts in cyber-space extolling the virtues of the Ackley Improved rounds, but PO said that unless you increase the powder capacity 5% it was not worthy of the conversion.
The greatest benefit of the AI may be the straight case gives better case life, BUT the AI's dont necessarily feed as well because of the minimal taper. The 257 Roberts and 6mm Rem suffered in the Remington short action, but in a longer action withthe bullet loaded out farther you can gain powder space and velocity.
I'll also add that a true Ackley Improved round can fire the parent load sfely in the improved Chamber. There are a lot of backwoods conversions out there that weren't properly done so results can vary all over the place. You have a wildcat when you're done that isn't highly resellable, but if it's what you want you pay the price. Myself, I wouldn't do it.
I've kind of played this game before. I've owned several 257 Roberts, currently have a 257 Ackley Improved Roberts. Not quite sure what I was searching for anymore. The Improved seems to perform best in terms of accuracy at velocity levels not much higher than what what I achieved with the standard 257 Rob.
I can get significantly higher velocities when I push it a bit but accuracy is not there. On the other hand my observations (don't have one) of the 25/06 have been that you can get higher velocities and accuracy at those higher velocities (other guys rifles) Maybe I haven't had the ideal action, barrel, load combination yet for the improved but my experience so far is that if you want the whole package use the bigger case. I've put about 2500 rounds through my Improved so I don't consider it a small sample. Barrel is a Douglas Air guaged on a FN M98 commercial action, Have experimented with bedding and 6 pounds pressure on the forend has worked best ( I set the butt of the rifle in a vise and add weight on a hanger on the swivel stud until I can slide a cigarette paper beteween barrel and forend). I'll probably play with it until the barrel is worn out and then will rebarrel it to <!--emo&???--><img src="http://beartoothbullets.com/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'><!--endemo-->???
It has been fun however and that's what this game is all about. besto.
I have a .257 that I am continually tempted to improve, but so far I haven't done it. In every example I have examined, whether other shooters at our club, articles or reloading manuals, it seems to me that a lot of the gain is usually acheived by higher pressures and or longer barrels. Almost all the .257 data, even +P, seems to be loaded to lower pressures than most modern rounds. So thus far I haven't jumped into that project. I still toy with the idea of having my .257 rechambered or rebarrelled to something because my particular rifle has been finicky about feeding reliably and disappointing in terms of velocity.
Commenting on something BCstocker said about 25-06's; I used to have a Mod 700 25-06 that was everything my .257 is not. It was reliable, utterly unfinicky about loads and absolutely the most accurate long range rifle I've ever owned. It was traded years ago to get a smaller rifle for my wife. I still miss it! (But at least I still have my wife! <!--emo&--><img src="http://beartoothbullets.com/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=''><!--endemo--> ) Good Luck deciding! ID
Thought I might throw in my nickels worth as I have tried a number of AIs. In 257 I started with a Win. Featherweight which was already improved, one of the most finicky rifles I have owned nothing was great and can't say how much gain over standard, didn't feed in the bump feed very well and after messing around with powders and bullets for a year and a half rebarreled to 280 Rem. In the same case as the 257 a 7x57 AI was one of the best rifles ever I ever owned shot every thing well and in before and after chrono runs the gain with 140 to 150gr bullets to same micrometer expansion was about 215fps. In a 338-06 I started with a AI and a 26" barrel worked up loads and then set the barrel back to a standard 338-06 loss even with the shorter tube was 117fps, again to same measured pressure. The one sleeper was a 35 Whelen, 24" barrel with Rem. factory ammo it was disappointingly slowww. In went the reamer but this time I ran the shoulder ahead apx. .050 kind of like a Hawk, left a decided pressure ring but only neck sized and with top loads that allowed 5 reloads before primers loosened gained 287fps. Now am working with a 375-06AI and its too soon to tell much. Conclusions: maybe in some chamberings AIs work but without more pressure P.O. was about right 100 to 150 is the typical gain in powder cap. without increasing chamber pressure, guess there are no free lunches.
I don't want to sound skeptical or ornery and this is something I've been wondering, is the attraction of the improved cartridges isn't just because they are a little different? Don't get me wrong, I'd like to try a 338-06 AI or 35 Whelen AI, etc... I definitely find odd ball calibers a little more interesting than standard flavor of the month offerings. <!--emo&--><img src="http://beartoothbullets.com/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=''><!--endemo-->
In the 270, 6.5, 7mm and 30 caliber guns, does 150 fps matter? It doesn't really seem to translate in to real trajectory savings and the animals certainly can't tell the difference. I doubt you could kill any animal with an AI that you couldn't with the standard chambering. Is it worth the extra powder and time at the bench? Is accuracy that much better or is the accuracy more dependent on the firearm? Just curious <!--emo&???--><img src="http://beartoothbullets.com/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'><!--endemo-->
thats my point, if there's not a significant increase in velocity or the improved version is more accurate for the improvement, I don't think I'll switch my brand. If I can push it up to 25-06 vel. shouldn't I just get a 25-06? I'd like to see a nice return on the investment not just the gunsmith on his 401K.
thanks all - keep the info coming
It would be a fun project, no doubt about that. A lot of people will swear by this or that caliber, some jumping on these new short magnums, some are jumping for the ultra mags. If you are a short action fan, I guess it's interesting, but the new short mags don't do anything that can't be done with a standard or existing magnum chambering. The ultra mags don't really give us anything new, if you compare them to the Weatherby Mags. I personally don't shoot well enough to realize the difference between a 300 H&H Mag, 300 winny, 300 winny short, 300 ultra or 300 Weatherby. None are any better or worse than the original until you get out to 500 or 600 yards, then it's as little as an errant breeze, or a blink. I'm not shooting at a living creature that far away, no way. Too many things happening between the muzzle and the animal. Muzzle to 250 yards, I bet there's not a whisper of a difference in practical trajectory or that an animal would respond differently if hit with one or the other. Same caliber, same bullet weight, etc.... Maybe, I've got it all wrong, though.
I own a .257 Rob'ts in a Ruger No. that had a very short throat, requiring that a 120 gr Nosler partition be seated into the case fairly deep. I then throated the rifle to allow a 120 Nosler to seat to the base of the neck and have 0.020" to the lands. I was then able to add about 2 grs. of IMR 4350 to that load, giving me about 150 fps. That gun now shoots that load at 2950 and gives groups of about 1 - 1 1/4" regularly.
A friend took an identical rifle and had it improved with a 40 degree shoulder. He could get less than 100 fps more than mine, but could not approach the groups.
In my experience, I would leave well enough alone and work on groups. Then I would hunt the biggest, nastiest, orniest mule deer I could find, throwing in an occasional antelope.
I'm thinking about another No. 1 in the A flavor rebarreled to the 257 Roberts. I really like that. If you want more speed in the quarter bore, there's the 25/06 or if you want to improve(??) that you have the 257 Weatherby. I think the Roberts and the No.1 is a fine sounding deer/lope rifle. Too bad there's no antelope around here. Probably be a good sheep rifle, but then I'd have to choose between the 7x57 RSI and it and I don't want to have to choose.
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