Looking for a bit of help on getting the right twist on my 257 Weatherby build. I want to be able to shoot the heavier black jack bullets so I intend to use a 1 in 7.5 twist, but I wonder how much that will hinder me on the lower end weights. Can I still shoot the 115 VLD or the Barnes TSX 100 Grain accurately? I appreciate any and all advice and experience you might lend. Thanks!
1 in 7.5 Twist 257 Weatherby
- Thread starter Totch94
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J E Custom
Well-Known Member
I would not recommend twist rate that fast if you want to shoot the lighter bullets at all. The average velocity for the 70 grain is close to 4000 ft/sec. The average velocity for the 100 grain is 3600 ft/sec and the average velocity for the 120's is 3300 ft/sec. so if you want to use both light and heavy bullets I would recommend the 1 in 8.5 to 1 in 9.5 range they will stabilize the 120's and allow the use of lighter bullets. Some of the 70 grain bullets may not survive the RPM at the 257 Weatherby Velocities but good bonded bullets should.
Just My recommendation
J E CUSTOM
Just My recommendation
J E CUSTOM
sierracharlie338
Well-Known Member
Based on the research I did 7.5 is what is recommended for the weatherby speed. I can't speak on the weatherby past that because I built 257AI and I am shooting the 110 and 117s at much slower speeds without any issue to this point but will be starting new load development with the blackjacks in a few weeks.
Thank you very much. This is what I was thinking but I just wanted to get some opinions to make sure I was clear. This is my first 257 Weatherby. I have always wanted one and decided that I am going to build one. I have a Defiance Tenacity Action in the safe and Manners Stock MCS-T stock ordered for it, just deciding on what barrel to do.
willfrye027
Well-Known Member
You could try some of the hammer bullets to give you more options other than the ACE. I've got a 1:7 25-06 coming and run into the same issue with limited bullets. Going to shoot 131 ACE, 128 hammers, and maybe 121 hammers.
Light Weight Cup and Core Bullets will have a hard time staying together with a 7.5 twist if your pushing hard , If you plan on Mono's it will be fine for both
Curious what the intended game and max ranges are with some of the longer .257 bullets? I love the QuarterBee and with the 100 grain TSX, 100 grain Scirocco, 110 Accubond, or 100 or 115 grain Partition I would use it on just about anything to 500 yards. Does the Blackjack add enough to make it worth a fast twist barrel and maybe losing the ability accurately push a lighter bullet at brain-melt speed?
Not to me it doesn't but it has sure revived the Quarter Bore nation
willfrye027
Well-Known Member
Out of a 25-06: 131gr ACE 3150fps MV
At 800 yards still moving at 2100fps carrying 1300 ft/lbs.
VS
100gr TSX 3400fps MV
at 800 yards moving about 1800fps and 700ft/lbs energy
The BC on the blackjack is exceptional. For me it's going to be a 1000 yard steel gun with the velocity/energy to kill a deer beyond my comfort level. Bucks the wind really well too which has been my Achilles heel in LR shooting and is limiting what I can do with my trusty 30-06.
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That sounds like a good solution. Do you have an idea what you think you will run the 131s out of the Roy at velocity wise?
willfrye027
Well-Known Member
No idea, sorry. Check the blackjack Facebook they've got lots of testing information if you can sort through it
sierracharlie338
Well-Known Member
Don't be afraid to reach out to the guys at blackjack if you have not already. They were very helpful in answering questions as they came up in my process.
J E Custom
Well-Known Member
I totally agree with this
, but if your barrel doesn't like the mono metal bullets, you are stuck, so I recommend a twist rate that will work for all bullet styles and brands. It is well known that I don't like building a rifle for one bullet because it is risky and may never reach it's full potential unless you try different combinations of bullets and powder in your barrel.Why push a bullet to it's limit, when you can use the best speed and twist rate. I have been down the superfast twist rate path, and found nothing but problems, so now I use the best twist for the size, weight and velocity for the cartridge. Chose wisely
J E CUSTOM
I totally agree with this
Why push a bullet to it's limit, when you can use the best speed and twist rate. I have been down the superfast twist rate path, and found nothing but problems, so now I use the best twist for the size, weight and velocity for the cartridge. Chose wisely
J E CUSTOM
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I think an 8.5 or 9 twist would be perfect but I don't shoot the heavies so a 10 twist has always worked for me
