257 Roberts Imp. 40
Wondering if anyone could share with me their experience with the Ackley improved cartridge versus the standard Roberts. (accuracy, velocity). Any info is appreciated!
Thanks, Ted
Thanks, Ted
0
-
I would think it would be worth it! I have an improved 6mm Rem called a 240 Page Super-Pooper...essentially doing the same thing with a 6mm. You can fire regular 257's and "fire-form" them into the "improved" rounds. They should be hotter and give a 25-06 a run for its money! 0 -
Tough question to answer. I have both calibers but different barrel lengths and weights.The 257AI delivers about 200 to 250 more feet per second in a 22" barrel as apposed to the standard 257 I have in a 20" barrel.Both are hunting rifles and will shoot 1" to 1@1/4" groups.If you are a reloader I would go for the improved as shooting the standard shell fireforms the brass and the standard brass is easy to come by making reloading simple. Hope this helps.Get a model 52 Cooper and have the best of both worlds; great deer rifle. 0 -
I have a 257 Roberts AI on a 1903 springfield action. Picked it up on a whim as a trade at a gunshow some years ago. At the time I was leary about it but wasn't trading anything of much value so took the chance. Turns out to have been one of my best acquisitions for an extremely accurate rifle. The accuracy is probably due more to the gunsmithing work of whoever rebarreled, added the Timney trigger, etc. than the fact that it is an AI. Fireforming cases is easy and this gun shoots the factory Roberts accurately as well as the AIs. Case life on reloads is excellent. I haven't tried to max out velocity and haven't measured it on a chronograph. The AI is an interesting approach and you can find quite a bit of commentary by using the search option on this forum. I like the 25s a lot and use the 250 Savage, 25-06, and 257 Weatherby as well as the 257 AI. Can't tell much difference in performance on game except that the 257 Weatherby seems to hit harder and put game down a little faster. Bottom line on the AI is that it is fun to load and shoot and is something of a conversation starter on hunting trips. Probably wouldn't spend a lot to get an AI versus a 25-06 or 257 Roberts if I just wanted a good 25 caliber rifle, but wouldn't hesitate to buy one either if I stumbled on another one. 0 -
bulzi,
More velocity. Every bit as good if not better in the accuracy department. But that depends more on how the rifle was put together and reloads you use. The one thing I find with most all the guys who use an improved cartridge in competition is that it is for case life, not increased velocity. The blown out shoulders grip the chamber walls better and help (a little bit) reduce bolt thrust. I find after a number of years with my 7x57 this seems to hold true. I know I can't push my 7x57 as hard as a 7mm-08 and have the cases last. I can only attribute that to case taper. Because I have more volume. Now, if the same 7mm-08 were to be improved and compete with a 7x57 AI then I think I'd see the AI win out in both categories.
Personally, I think the .257 AI is worth doing if you build it right from the get-go. There are 1-9 twists and 1-8 twists out there that will stabilize long bullets in .257. Most of the super long bullets are custom made like Wildcat. The length of barrel allows you to get the velocity potential out of the round. If hunting I would call it 24" minimum and bench shooting 26". Although I have no problem with a 26" barrel. My regular .257 Rob has a 26" barrel and always got better velocity than my 20-21" AI. I really felt that was a waste of a good barrel when cut that short in that caliber.0 -
same as the above, I've got one of each but set up differently. The std. .257r is a light hunter, while the a.i. is a light varment rifle. both do their job well. 0 -
Thanks for the great comments. I am going to build a custom varmint/deer rifle on a remington action and have settled on the .25 caliber. I like the efficiency of the Roberts versus the 25/06 and really like the idea of imroving the Roberts. Thank again and keep sharing your experiences. 0 -
I read somewhere that P.O. Ackley liked the .257 Roberts improved more than any other improved cartridge he did...it should make a cool gun for you. 0 -
bulzi,
I don't know about favorites, but Ackley said his most productive conversion was the .250 Savage. Most improved anyway. If you look at it, the "International" (not IHMSA) and eventually the 6mmXC came to about that. Although the 6mmXC was a shortened .243 it approximates the dimensions of the .250 case necked down to 6mm and improved.
Something to consider, and I don't know how easy it is to form brass, is to 'reverse' improve a cartridge. Push the shoulder back instead of blowing it forward. Still push the case walls out so that you have less taper. What this does is give a longer neck (helpful in some cases, not others) and helps with throat erosion. therefore you can load it a little hotter. It probably wouldn't be necessary in the .257 Rob, or any Mauser case, as they already have reasonbly long necks. You still get some case capacity increase too. It's kind of a win/win situation. Unless of course it's too much of a pain to form cartridges. I haven't done it personally so I don't know. Some of the guys I shoot with who have, don't mind doing the extra work like that if it's going to pay off. For them it seems to have.0
Please sign in to leave a comment.
Comments
8 comments