I've no practical experience regarding the subject and would like some feedback before ordering a barrel.
Thanks!
Joe
1 in 10" is the 25 cal standard, but I'd do a 1 in 9" if I had a choice. Shilen recommends it, and I've read credible evidence elsewhere that suggests to me a little more twist than standard would be a good idea.
As bullets get longer and sleeker the 1 in 10 twist becomes less viable. Being a 25 cal. nut I have tried 120's in many different rifles and cartridges with 1 in 10 twists. Not in all cases but in the majority accuracy was better with the lighter shorter bullets. If I were getting a new barrel with the intent to shoot 115 through 120 gr. bullets I would opt for a 1 in 8 or 1 in 9 twist. May save some frustation in the long run. The faster twist will run lighter bullets just fine should you want to shoot some 75's or 100's.
I have found the 10" twist ok at Weatherby velocities but inadequate in the smaller '06 case. I would opt for the faster twist.
JW
Absolutely you'll be fine, some of my best 25 cal shooting has been with the 115-120's in a 10 Twist with 7828.
Dober
Bullets aren't getting shorter. I can't see the harm in a 1/9" if starting from scratch.
You are right on the threshold there. I found that I couldn't stabilize 115 Ballistic tips with my 10 twist. I suspect there are others even harder. If you intend to shoot the 115 and 120 VLDs you will want a 9 twist. Velocity only helps a little. It is not a magic pill that lets you get away with inadequate twist rate.
I run into the same thing with 14 twist 22s and the 55 grain BTs, Vmaxs et al.
120 Partitions are fine for me w/1-10" twist, ditto 115 BT's, & 120 Grand Slams.
MM
1 in 10" is the 25 cal standard, but I'd do a 1 in 9" if I had a choice. Shilen recommends it, and I've read credible evidence elsewhere that suggests to me a little more twist than standard would be a good idea.
I've heard people who've had problems with that twist rate in those bullet sizes, but my 257 AI has a 1-in-10" twist and shoots the lights out w/ anything from 75-117 gr (I haven't shot any 120s yet) bullets... although I will admit that while it shoots sub-MOA w/ 115s & 117s (about .9"), it shoots sub-sub-MOA w/ 75s and 100s (.30").
The mix of results exhibited in these posts is why I'd build at 1:9" to get away from the edge.
I'd only concern myself with the edge if I was serious about using a VLD.
Dober
Dober,
Do you feel 1:9" is too much otherwise? I'm thinking it would give a nice stability margin without overdoing things. It's commonplace for 8 and 9 inch twisted 6.5s to shoot shorter bodied 120s very well, so a longer 120 gr. 257 should be fine even if not a VLD.
Am I way off base?
m
Probably not, but I've had such good workings with the 10's that it'd be tough for me to stray unless I had an interest in the Burgers and such.
Which at this time I don't so I'd just go with what's done me well for a long time.
Tough 4 this old perro to change I guess.
And you're right about the 6.5's, I really like a 8.5 in that.
Dober
The mix of results exhibited in these posts is why I'd build at 1:9" to get away from the edge.
If I were building one for the heavies specifically I would too.
Probably not, but I've had such good workings with the 10's that it'd be tough for me to stray unless I had an interest in the Burgers and such.
Which at this time I don't so I'd just go with what's done me well for a long time.
Tough 4 this old perro to change I guess.
And you're right about the 6.5's, I really like a 8.5 in that.
Mark is right that the 10 is fine as long as you stay away from the real long bullets. Mine would NOT shoot the 115 BTs. I didn't even try the JLKs or Bergers.
It shot everything else, including the 120s I tried- none of them were VLDs however
I like the 8.5 in 264 as well.
Dober
The factory Federal 120gr Fusion shoots teeney tiny groups in my 10" Tikka...
120 Partitions are fine for me w/1-10" twist, ditto 115 BT's, & 120 Grand Slams.
MM
+1
My 25-06 has a 1-10 twist and shoots those bullets accurately.
Do you feel 1:9" is too much otherwise? I'm thinking it would give a nice stability margin without overdoing things. It's commonplace for 8 and 9 inch twisted 6.5s to shoot shorter bodied 120s very well, so a longer 120 gr. 257 should be fine even if not a VLD.
Am I way off base?
m
Though not really necessary for anything short of something similar to the VLD, IMO, the 9" twist shouldn't be problem for anything heavier than 90 grains.........below that could possibly get borderline but probably not.
Don't know for sure though as I've not seen the need, so just theorizing..............
MM
Keep in mind that this 10" twist thing for 25 caliber bullets goes back a long way; kind of a traditional thing.....I don't know how far but when the Roberts came out in the 30's it had a 10 twist matched to those shorty 100 gr round noses.....
Ken Waters opined quite a few years ago that he felt the 25/06 would be better with a faster twist.....especially with the longer 120's.
Todays bullets are longer than they were when the 10 twist thing got going.You have things like Barnes and other monometal bullets, Bergers, S'co's, etc,. You also have better, more uniform bullets that stand the heat from the faster RPM's.
If I were building a 257 Roberts or a 25/06 today, I'd order a 9 twist Kreiger,Brux, Bartlein, etc and never give it a second thought.JMHO......
I have a rockcreek 5r 1-10" barrel sitting in the corner waiting for the factory barrel to die.
A 1-9" would make me feel warm and fuzzy -oh well 1-10" will ahve to do.
My 1:10 shoots Berger VLDs very well at 500 feet above sea level at 3000fps from my Ruger .25-06.
In .243 I like 1 in 8.5" to 1 in 9" twists, In 264 1-9 or faster so just to make sure I went 1-9 in .25 but haven't put it together yet. A 1 in 9.5 should be just right for the 115 Berger depending on velocity.
I subscribe to the faster twist improving straight line penetration after impact theory, but this is debatable.
I know this a 1 in 11.5" wont stabilize a 115gr. Partition.
Sure stabilizes 100's though.
DS,
I have a 25-06 with a 10" twist Shilen barrel; it shoots quite well the 115-120 grain bullets, but it shoots better with bullets of 100 grain weight. Brand of bullet doesn't seem to make much difference, and I think it has to do with rate of twist. If I had it to do over, it would be done with a 9" twist.
In is my opinion, that even though the 10" twist will stabilize the heavier, longer bullet, it is right on the edge. With the really high quality bullets we have today, I see nothing wrong with a twist being a bit toward the fast end of spectrum; it is certainly better than being just a bit too slow!
M Bell