257 Roberts Ackley Improved

[tdoyka]

i might be getting rid of my tc venture in 25-06, reloading dies, and 80 some pieces of rem brass. i'll be buying a encore in 257 Roberts Ackley Improved, 1 in 10" twist, in a 21" mgm barrel. i sent an email to mgm barrels to make sure it has a 40 degree shoulder, so that is taken care of. i have 2 full boxes of 115 grain nosler ballistic tips. do these work for deer, busting a shoulder, etc, or should something else work?
should fireforming be 87 or 100gr? would imr 4350 work? the ack imp is new to me, any help will be greatly appreciated...

 

[areaone]

I have owned a 25 06 since 74 and a 257 AI since 85. My question to you...Why are you duplicating ballistics from a 25 06 to a 257 AI. Any reason why you are going to a 257 AI insted of staying with the 25 06, You will be fireforming, finding 257 brass(not always available) and running the risk of head separation if you are not careful fireforming. Juist do not see what there is to gain. That 25 06 cartridge is a great long range medium game round. Try fireforming with a fast powder and make sure the bullets are jammed or there will be problems, 87 grs will work fine and 4895 or the like in a med load.

 

[25AI260]

well for less powder used... less kick as well for the same performance.. check out cartridges of the world " cow" 10th an 11 the edition for the 250 Humdigger.. i'm sure its the same or real close as the 257 rob IA.. except the hummer has a 45* shoulder...
i guess you could use .243, 7-08 even .308 brass with a good jam to fireform... also, you mite better off using 4831sc powder45.5.. 100gr nosler.. fed 210
good luck on the build

 

[tdoyka]

since i had a stroke the right half of my body only gets about 20%. i've wanted a 257bob ai for years, and i get the chance now, esp with the encore. i shoot leftie(alway have)so some bolts are becoming problematic to me.
besides, i get another gun ;D

 

[Larryh128]

115 Ballistic tips are a good bullet for it, you won't have a problem with them. With that said, you are better off going to the Barnes TTSX after you use them up. Shoulder shots aren't an issue and less of an issue with the Barnes TTSX.

 

[Larryh128]

4350 will work for fireforming as long as you can get a "touch" on the shoulder when the action is closed. H4895 is a better choice if you have it available. Either the bullet has to be jammed in the rifling or the shoulder touching. I MUCH prefer the shoulder touching. Great round, you'll like it.

 

[CaptainMal]

540 yards - 257 Roberts - 115 Nosler Ballistic Tip... End of comment.

 

[tdoyka]

i.........uh.....the......well.......

that will work captianmal way to go!!!!!

 

[gene so]

I have had two .257 Ackley Improved. One a standard 257 Roberts in Remington rifle with a rechamber ing, the other a custom made Varminter with a steel sleeve.
This is an old established cartridge and really "made" the whole idea of improved cases legitimate. A Stock rifle, with factory Remington ammo: 117 grain round nose bullets,3031 powder and pressures meant for the pump action rifle originally chambered at the factory, it was a mundane cartridge. The improved version had much more capacity and absolutely stuffed with surplus 4831 ( usually with a drop tube) the performance improvement in a bolt action was dramatic. There was nothing like it, because the only other middle sized cartridge was a 25-06 which at that time was a custom proposition and the 6mm's didn't even exist at that time.

Nowadays with all the possibilities the .257 is still a pretty neat cartridge. It does not feed well in a magazine with its steep 40 degree shoulder, but does fine from a single shot. I see your limitation are basically what you want to do with it. A 24 inch barrelled rifle with a 1-10 twist will provide you with a fine hunting/varmint rifle. A pure varmint rifle could be a heavier 26-28 inch weapon with 1-12 twist which delivers high velocity lighter wieght, but high BC, bullets to a target a long ways away from you.
I wish you well.