257 Roberts IMP

[B SLAGLE]

What kind of round is a 257 Roberts Ack IMP. Are they any good ? I am looking for someone with some Info . I have just got one It has a Rem 40x action Keriger 28" barrel 1 & 8 twist using 115 vld bergers and 50 gr of N160.

 

[mwezell]

It's a great little cartridge but it doesn't fit into BR very well. They can be a very good and accurate hunting round though. It's really kind of a "tweener" in terms of long rage cals. and a big fault is the lack of bullet selection.--Mike Ezell

 

[Bro.D]

I remember reading an article in Precision Shooting several years ago that stated of all the Ackl, Imp cartradiges the 257 had the most improvement over the parent case. Wish I still had the mag and I would give you the true info. Maybe someone still can find it Bro.D

 

[Boyd Allen]

I don't know if PO Ackley's two volume set is still in print, but that would be a good place to start. Also, I believe that it was the .250 Savage Improved that gained the most percentage wise.
Here is some data that I found on the web. I have no idea if it is any good. http://www.reloadbench.com/cartridges/w257ackimp.html
This should give you something to read. http://shootersforum.com/showthread.htm?t=5813
, as should this http://en.wikipedia.org/wiki/.257_Roberts

 

[Octopus]

The 257 Roberts AI is fun. I shoot several 25 caliber barrels including the 25 BR and the 257 Jon Deer which is very similar to the AI Roberts.

Both BIBs and Berger are making excellent 257 bullets.

PM me with your email address and I will send you more info

 

[LHSmith]

I remember reading an article in Precision Shooting several years ago that stated of all the Ackl, Imp cartradiges the 257 had the most improvement over the parent case. Wish I still had the mag and I would give you the true info. Maybe someone still can find it Bro.D

Most velocity gain was the 25/35 WCF @26%, the 30/40 Krag (26%), 250 Sav. (19%), 30/30 (13%), 300 H&H ( 11%), 257 Roberts (9%)

After re-reading the PS article by Bob Jourdan, the 257 AI becomes a poor candidate when one considers it's net gain is only 4% when compared to a WW +P factory load. The afforementioned 9% is when compared to the standard Roberts loading.
FWIW other popular AI's with % gain.....243 (8),280 (8), 7/08 (6), 6mm Rem (6), 22/250 (5), 223 (5), 260 (4)

 

[Octopus]

The velocity gain with the AI change is just an extra. When you do an AI it makes the shoulder angle sharper. This helps with both accuracy and barrel life in most cases.

The 260 AI is a good example.

The only negative with the AI is getting the FL sizing die correct usually cost a few more bucks.

 

[trouble]

I have a 257 Roberts AI that I use on woodchucks and deer but trying to find good long range bulloets for comp. found my choices so limited and bc less than even good 6mm bullets I went to 6.5 x 57AI. Since then I came up with my own improved 6.5x57 on a 30 degree shoulder which has been more consistant and gives the same vel. as a 6.5-284 with a couple grains less powder. I shoot this case in 600 & 1000 yd. comp.

 

[Octopus]

Lack of quality bullets is an ongoing issue with the 257. I have found the Berger and Bib bullets in 87-88 gr to be very good. They are both flat base. Out to 300 yards they are excellent. So far the best I have found in the longer lower drag bullets are the Bergers. If anyone can suggest better please post.

Thanks

 

[R.G. Robinett]

For deer hunting, the .257 Ackley is a GREAT cartridge: my current barrel (23", #3 contour, PacNor - 1:10", 5-groove), with a 'poochy' [RL-17] load, lobs 110 Gr. BIB BTs at 3333 FPS! My long-time 'pet load' (H-4831/110 t0 120 Gr. bullets weights) usually produces just shy of 3100 FPS - and, over the years, many mule deer, pronghorns, and coyotes have proven it tolerable D) - on last falls adventure, the extra 200 + FPS sure didn't disappoint! Oh, and with good bullets and a well built rifle, it's capable of extremely pleasing precision. RG

 

[Octopus]

Just so you all will know Randy Robinett makes the BIBs 257 bullets which are the best I have ever shot in the 25.

My 25 BR reamer is a dead copy of the one he has on file with PTG. I used this same reamer, just ran it in deeper to make my 257 Jon Deer (25-308).

The 25 BR with a 25" barrel shoots BIBs 88 gr bullets @ 3300 into bug holes.

The 25-08 with a 26" barrel shoots the BIBs 88 gr bullets @ 3600 into bug holes.

I have been shooting the 25s for 50 years and good precision bullets have always been the limitation.

Maybe if some of you will chime in we can get Randy to make a 75 and a 100+ gr bullet for the 25.

His bullets are works of art.

Octopus