Thanks for that.I have learned a lot from this site over the last few years. Lots of great information. It saves people time on load development and which products not to use.Not poking fun but extremely impressed!
Thanks for that.I have learned a lot from this site over the last few years. Lots of great information. It saves people time on load development and which products not to use.Not poking fun but extremely impressed!
Now that this bullet has been around a few months has any one put enough down range to have a good idea how they hold vertical at 1K?
What twist are you running ?Not 1000 yards, but last weekend shot a 200-13x off the sling at 600. Weekend before, shot 200-8x. I ordered another 500.
Not 1000 yards, but last weekend shot a 200-13x off the sling at 600. Weekend before, shot 200-8x. I ordered another 500.
7.5 twist krieger in my 6.5 Creedmoor. 30” barrel. 41.8 grains of H4350 in hornady brass. 2780 fps
I have been shooting the 6.5 WSSM since 2009 and have not found a cure for the hard bolt lift!! Doesn't matter weather I run 43 H4831 or 49 with 140.....bolt lift is the same.....H A R D !!!You have a good eye. Yes it is....I have been testing an AI version for a friend/GS/competitor. I am having too much hard bolt lift at moment to say anything definitive,
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I have been shooting the 6.5 WSSM since 2009 and have not found a cure for the hard bolt lift!! Doesn't matter weather I run 43 H4831 or 49 with 140.....bolt lift is the same.....H A R D !!!
LOVE the cartridge....HATE the bolt lift!! If you find a solution I would love to hear about it!!
Tod
Hey Tod. I have a 6.5 WSSM for my deer rifle and, like Drew, am trying a 6.5 WSSM Ackley in an F-Class rifle. I don’t have an answer, because I don’t know, but I haven’t experienced any hard bolt lift on either, unless I’m into a max charge. My deer rifle is a 8.5-twist shooting 140 VLD Hunting bullets. I resize cases with a Redding F/L bushing die for the straight version. I put a 7.25-twist on my F-Class rifle and I’m shooting 155 gr. Cauterucio bullets in that one. Just starting load development with formed cases. I resize those cases with a Whidden custom die set up for the expander buttons. Drew was using my die and had hard bolt lift and experienced really high pressure with loads below where I started with. Maybe he’ll chime in again, but he may have even had his barrel chambered up with my reamer also. I dunno. Make heads or tails out of all that.
Long answer: I think FrankG is probably using the Miller SI rule at 60 F and standard pressure at sea level and assuming a 1.5" bullet, which I saw posted by "Fast14riot" in thread "New Sierra 6.5 mm 150 gr Match King" on the main forum board today. When I do that, I get Miller SI of 1.44 for 1:8 twist, so I think Frank is calculating minimum twist rate for a 1.4 corrected Miller SI. In recent work, Litz said some improved results can be achieved by stabilizing up to a 1.5 Miller SI. My calculations show a 1.53 corrected Miller SI from a 1:7.75 barrel.
After looking at other similarly-low form factor 6.5 mm bullet data especially 140 and 147 ELD Match bullets, I am skeptical that 1.5 is the right bullet OAL. I think the correct OAL for the SMK may be closer to 1.45" instead of 1.5". If the bullet is indeed something closer to 1.45", then Miller SI at 1:8 twist is 1.59, and it is 1.50 with a 1:8.25 twist.
Short answer: At 3000 fps, if bullet is 1.5" long you may want a 7.75 or faster twist. If bullet is 1.45" long, then 8.25 or faster will be good.