Tested some loads today **update**

[KDX]

I'm in the process of trying to get some loads suitable for deer sized game made for my .257 AI. I bought some 100gr Nosler Ballistic Tips to try and used H4350 for powder and Winchester magnum primers (2.890" OAL). Hodgdon lists the max @ 45gr of H4350 (2970fps) so I started @ 46.5gr (5 shots) and then jumped to 47gr and went up in .2gr increments (all 3 shot groups) to 48gr. I'm not overly impressed with the groups but 47.2gr and 47.6gr show some promise. I don't know what happened with the 48gr group but I must have really pulled one there. I'll have to load up a few more and take the chrony out to see where I'm at. I'm looking for 3200-3300fps and then I'll start to play with the seating depth.

The one hole way up was from a sighting in session a couple days before when I threw the scope on this rifle. It was about 10" left and 5" high when I started.

 

[track]

The 47.2 grain group has potential. It's great to have that happy medium of accuracy and high velocity, however I never substitute an accurate load for 5% extra velocity. I don't know if there is a load using VV160 or VV165 for your 257AI, however it is a very stable powder and has so much potential with various cartridges. Sticking with the KISS program, a seating depth change may improve with tighter groups.

 

[Kelly Timoffee]

I just tried some 115gr VLD Hunting bullets that I want to use for a deer/coyote rifle.This is however in a 25-06.

They had pretty good accuracy overall with some hitting a nice sweet spot, velocity was also fairly good for my most accurate load.

Not sure if you want to go that heavy but I was after accuracy before velocity and in this case the heavier projectile worked out.

I used H1000 powder and it seemed to like heavier charges resulting in less deviation in speed and had nice vertical spread.

 

[gunrunner8]

KDX, I had few good hunting experiences with Nosler BTs exept with heavy for caliber bullets in 338 and 358 bores. Sure they will group on par with target bullets but unless you will be useing them for varmint hunting you are heading for dissapoitment. IMHO their jackets are to thin for reliable performance on heavier game. Now before I change the bullet I shoot it in several 1 galon milk jugs with some plywood in between for self assurance and I done dozens of like experiments over the years. GR8.

 

[KDX]

I'm going to mess around with the 47.2gr load and see what it chronographs at. VV powder isn't too common around here, but I might give H4831 a shot to see how it works. It's listed right after VV160 on the burn rate chart. I'm getting 3735fps with 75gr V-Max and XBR powder for a varmint load. Not sure if my 1-10 twist barrel will handle heavier than 100gr bullets.

 

[Eagleye]

KDX; Your 1-10" twist should handle all bullets up to and including 120 grain Flat bases.
I had a standard 257R, and it would shoot 120 Partitions into tiny groups.
1-10 twist barrel. MV was 3000 and pennies with RL22.
Eagleye.

 

[Pathfinder]

KDX, I had few good hunting experiences with Nosler BTs exept with heavy for caliber bullets in 338 and 358 bores. Sure they will group on par with target bullets but unless you will be useing them for varmint hunting you are heading for dissapoitment. IMHO their jackets are to thin for reliable performance on heavier game. Now before I change the bullet I shoot it in several 1 galon milk jugs with some plywood in between for self assurance and I done dozens of like experiments over the years. GR8.

About Nosler BT's it really depends how hard you push them....but I agree that North of 3000 fps....you may be disapointed on heavier game.

Ive had good results using them on deer (270 win. 130gr.)

 

[KDX]

This is the background image for the Nosler BT bullets from their website. Supposedly they aren't supposed to be pushed beyond 3200fps.

 

[Pathfinder]

This is the background image for the Nosler BT bullets from their website. Supposedly they aren't supposed to be pushed beyond 3200fps.

Yep...sounds about right...the only one I found in a deer was a head on shot...found it along the spine....I think there was about 60% of weight retained...expended all energy...very dead deer...very suddenly.

 

[Kelly Timoffee]

Another bullet I have had success with and would be suitable for your needs is the Scirocco II from Swift , they are high BC premium bullets designed for use in fast chamberings.They offer a .25 in 100gr.

About Nosler BT's it really depends how hard you push them....but I agree that North of 3000 fps....you may be disapointed on heavier game.

Ive had good results using them on deer (270 win. 130gr.)

 

[Pathfinder]

Ill put in a plug for Matrix.....home grown bonded bullets...they usually shoot lights out in other chamberings Ive tested them in. Im got some 25 cal 125gr. that ive yet had time to try.

 

[KDX]

I went out today with the chrony and 6 100gr Nosler BT bullets loaded with 47.2gr of H4350 and Winchester Magnum primers. The average speed was 3232fps and the 6 shot group size wasn't too bad. I'm going to call the two flyers as technique induced and call it a day for a deer hunting capable load. Next up is a different scope for this rifle and I'm done.