Ollin Magnetic Digiscoping System

Someone Stop Me

I picked up a 257 Winchester Featherweight and had it Ackley'd. Shoots the 100 TTSX real nice. Amazing to stick a factory case in the action and go pow, and then eject a completely different looking case, always makes me look and smile. It would be fun to take to Wyoming on an antelope hunt, but it may be too pretty to drag through the sagebrush and may not be any antelope hunting in Wyoming in the near future. I'd try the 185 TTSX in the 338-06, might lessen the recoil a bit.
 
I have been daydreaming quite a bit lately about building a stalking rifle off of a CZ 550 FS or a Ruger 77 International in .257Ackley Improved. Have to think a 115gr. Barnes TTSX doing around 3000fps would be pretty serious medicine for pronghorn and eastern Whitetail with a light 2-7x scope on top.

Would it be redundant for existing rifles I already have in the collection? Absolutely.
Could I accomplish the same or better with a factory-standard rifle and a commercially-available cartridge? Without a doubt.
Might this rifle turn into the murder weapon that my wife inevitably uses on me? Indubitably.

I've read through several old threads and see that some of you tote the .257AI. Any thoughts on this particular cartridge? Anyone put together a similar stalking rifle concept?
What other rifles/calibers do you have that would do the same job? I am a "less is more" type of guy. Usually when i get the itch for a new gun. I scratch that itch by opening my gun safe and re-appreciating a firearm i all ready have.
 
The 257 AI is a sweet little round, I reload one for my old man. I'm finishing a build of a 6mm Remington AI right now with a fast twist barrel. We will be shooting similar weight bullets since I went with the 8 twist. Might want to add 6mm AI to the consideration, they are the same parent case and 6mm has better bullet selection. I say do it, few things funner than building a rifle.
 
The 257 AI is a sweet little round, I reload one for my old man. I'm finishing a build of a 6mm Remington AI right now with a fast twist barrel. We will be shooting similar weight bullets since I went with the 8 twist. Might want to add 6mm AI to the consideration, they are the same parent case and 6mm has better bullet selection. I say do it, few things funner than building a rifle.

Which powders do you like for it?
 
As an ow er of a 257 AI and a Ruger m77, go for both.

My 257 AI is built on a tried mauser and is incredibly accurate.

The Ruger m77 is one of the smoothest actions around. My 1976 vintage is in rebarreled to 280 AI and shoots the lights out.

Can’t go wrong with either
 
After a good bit of tinkering, I think I finally have the .257 AI just about dialed in. I initially started with a ladder test with 100 gr. Barnes TTSXs over AA4350. ESs and SDs were fine, but not much to write home about. I was somewhat disappointed with accuracy, though. Knowing that this is an unbedded, full-stocked rifle prone to heating up rapidly and using a 10x Swaro, I threw out 5-shot groups and went with the average of the two best 3-shot groups from each 5-round string (I know, I know, statistical insignificance, whatever). I also threw out one outlier from each 10-shot group when calculating average velocity and SD. All loads were with Nosler .257 Roberts +P brass fireformed to .257AI and CCI BR-2 primers. Insert your usual disclaimers about verify for your own purposes, no representations and warranties, please don't blow yourself up using my loads, etc. but load data was pulled from the Hodgdon/Accurate Reloading Center website.

Charge- AA4350COALAvg. Velocity (9 shots)Extreme Spread (9 shots)SD (9 shots)3-shot Avg.
50.0gr.2.885"2868fps90fps26.70.900"
50.5gr.2.885"2928fps39fps15.61.165"
51.0gr.2.885"2977fps67fps21.81.081"
51.5gr.2.885"3028fps40fps12.21.313"
52.0gr.2.885"3073fps33fps20.51.050"

I then decided to perform a seating depth testing using the 52.0gr. charge, based on the lowest ES. Those results were more encouraging:
Charge- AA4350COALAvg. Velocity (9 shots)Extreme Spread (9 shots)SD (9 shots)3-shot Avg.
52.0gr.2.835"3049fps* (7 shots due to Labradar gremlins)104fps (wtf)14.50.793"
52.0gr.2.810"3086fps54fps18.40.831"
52.0gr.2.785"3042fps (8 shots/ aforementioned Labradar gremlins)40fps16.70.943"
52.0gr.2.760"3046fps25fps8.70.649"
52.0gr.2.740"Cold killed the Labradar batteries at this pointNullNull0.784"

One of the 2.760" COAL 3-shot groups measured slightly larger than a gnat's ass at 0.266". That should do for now:
1702170052718.png

I'm not enamored with velocity, though. Knowing that I am working with a 21" barrel, I still thought I could consistently average 3100fps. Accurate's load data predicts 3293fps from a 24-inch barrel with 52.0gr. of AA4350. I have a pound of Hodgdon 4831sc on hand and may tinker with it, although I would expect it to give lower velocities based on it being a slower burning powder than the AA4350. Based on the advice of one of the forum's sages, I might also experiment with magnum large rifle primers. I also have a stash of Winchester and CCI standard LRPs. The temps were in the low 30s, so I wonder if that combined with the BR-2s could explain the SDs being a bit all over the place.

What say you, wise men of the interwebs? Another powder or primer you might suggest I experiment with? Or should I leave well enough alone with a 2/3 MOA group and a sub-10 SD?
 
With the increased case volume of the AI, i go with slower burning powders.
I'm running Hodgdon Hybrid 100V in my Ruger 77 MKII (22" barrel) to +P in "standard" 257 Roberts with 100-115gr bullets.


RL19, RL22, IMR 4831 have been good powders in my AI. (Savage 111 with 24" barrel)
I did find a nice load with RL19 and 120gr Nosler Partition.

I got 7-1/2lbs of Vihtavouri N555 at a really good deal.
Did some figuring on QL & shot a ladder with it & 115gr NBT.
I like this powder for the case capacity and accuracy too!
 
Like our friendly 7 mag lover stated, I’d try to find some H100V. I’ve been using the stuff in my 280 AI (and 25-06 before that) and it’s almost made it to my go to spot. Good velocities can be found. It’s about in the middle of 4350s and 4831s in burn rate.

If you can, I’d also see about the new 101 LRX from Barnes. I’ve found better velocities and SD’s when using LRX compared to TTSX of the same weight class.
 
Like our friendly 7 mag lover stated, I’d try to find some H100V. I’ve been using the stuff in my 280 AI (and 25-06 before that) and it’s almost made it to my go to spot. Good velocities can be found. It’s about in the middle of 4350s and 4831s in burn rate.

If you can, I’d also see about the new 101 LRX from Barnes. I’ve found better velocities and SD’s when using LRX compared to TTSX of the same weight class.
Yeah, I’m going to have to pick up a pound to tinker with over the off-season. Not finding any published data for H100V in the .257 Ackley using projectiles in the 90-100gr range, but I figure I can start with max loads for .257 Roberts and work up slowly to pressure signs.

Also ordered a box of the 95gr. Hammer HHTs. Feels like 3200fps should be easily attainable with their lower bearing surfaces.
 
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