VLD Pilot
Well-Known Member
7.75 works fine in a 257 Wby.
.25 cal 131g .330G7 bullet from Blackjack Bullets for you to drool on ...
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Yeah thought you'd get away with less twist in the Wby.
duckhunter175
Well-Known Member
Built my .257wby on a 7.5t Proof which was the recommended twist directly from blackjack. I never ran the 131s much over 3300 but I'm sure some guys are getting close to 3400 which was my goal.
If I did it over again I'd likely run a 25PRC/SAUM/SST and a 7t so I could run the heavier Hammers as well.
1-7 will work for the ace but 1-7.5 to 1-8 would be ideal to keep the rpms down and put less stress on jackets. The blackjacks have seemed to do just fine with 1-7 over 3300 fps. Although they are made by Sierra who is known for having thicker jackets. So just because the ace can handle the higher rpms does not mean the newer bergers will as well. And one day when Hornady comes out with a eld-m I doubt it will as they already blow up at PRC velocities. 5R rifling is supposed to be easier on jackets to if you have that option. It's always nice to set up for more than just one bullet. Current times provide a good example why, the black jacks have been out of stock for months.
Left Hand Dave
Well-Known Member
^^^^ This is an important point. I did some load work up on a 1-7.5 twist .257 Wby that was chambered with the Blackjack reamer. I could not get the consistency I was looking for with the Blackjacks. I also didn't get the speed everyone talks about but that is normal for me. I settled on the 121 Hammers that shot great. I would look at what gives you options.
Also you may want to ask and compare opinions on the Blackjack reamer compared to the standard reamer. It may be interesting to know as all these are long bullets.
Also you may want to ask and compare opinions on the Blackjack reamer compared to the standard reamer. It may be interesting to know as all these are long bullets.
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VLD Pilot
Well-Known Member
Some say an 8 will work just fine.
Blackjack recommended twist rates are what's required to maintain 100% stabilization/bc value to 000' asl at 32° F. My 257 blaser is 7.75tw, my 25sst is 7.5, of 4 25 creed barrels are 7. I've read that over twisting bullets can potentially degrade the accuracy potential of a rifle/bullet combo, but do not know if it is true or not.
VLD Pilot
Well-Known Member
Bullets will blow up before accuracy deteriorates.
VLD Pilot
Well-Known Member
Picking up my rifle tomorrow. The loading and breaking in begins. Look forward to reporting my results here. Lots of RL26,H4831sc, H1000 on hand. Starting with RL26 so may not even get to the others.
Blackjack told me to keep the MV below about 3200 in a 1:7 twist to keep them from blowing up.
Berger said it won't be a problem to run their 115, 133, 135gr in a 1:7 twisted weatherby.
VLD Pilot
Well-Known Member
Bergers seem to hold up to all velocities in all twists. Sierra's also do well in most cases. I think they are more than likely being conservative with that statement. I've never heard of any 7 twist 257 Wby blowing up a 131 BJ bullet. I say have a ball with any .257 rifle at any (reasonable) speed with the 131s.
VLD Pilot
Well-Known Member
Buddy's running them 3370 with his 257 Wby and a 7.25 barrel. No issues after almost two boxes of BJs. His barrel is probably pretty wore out but no blowups
