I'm curious about your dope for the 90gr bullet in your 243. The numbers I've run would put this bullet marginally stable in a 10 twist 243, which would likely compromise some of it's ballistic coefficient. Do you find your come ups match the BC or do you have to adjust and come up a little more? For example, I shoot 95gr VLDs from my 10 twist Howa. They are wonderfully accurate out to 600 yards (as far as I currently have access to shoot). I find the my true BC with this bullet is closer to .405 than the factory's printed .467 and attribute this to the slow twist rate of my rifle. I'm heading to the range today and hope to have my own input on the matter shortly.
Sierra Gamechanger bullets.
- Thread starter lee31
- Start date
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Well that was easy. The 90gr Gamechanger in my 10 twist 243 is NOT STABLE. Put up two groups at 100 yards, one right at MOA, one just under. Tried to shoot at 200 yards. No luck. Couldn't hit an 8" plate. Zoomed out with the scope and the impacts were 1-2 feet above the target hitting in an area about 3 foot wide. For what it's worth I'm at about 640 above sea level and it was about 36F on the range today. Most disappointing is I called Sierra when these came out and asked their recommended twist rate and the tech I spoke with said "they will stabilize in a 10 inch twist". Wonder if they will take them back.
RockyMtnMT
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I used 0.14" for tip length on the JBM calculator; SG at 36F is 1.257. With 0.0" set for the tip, SG is 0.984 at 36F (1.030 at 59F). Might work in warmer weather or higher elevation but I don't think you could call these stabil from a 10" twist.
kiwikid
Well-Known Member
antelopedundee said Bruno Shooters Supply has them for $27.65 per box of 100 cheapest I've found. Approx shipping by USPS [I assume a small flat rate box] was around $12. So about $33.50 per box delivered. At my local Sportsman's Warehouse they were $39.95 plus 7% sales tax. The same 2 boxes would have been about $18 more at SW.
antelopedundee, thank you for the link to Bruno Shooters, I will send them an email and ask how much it costs to obtain an export permit for bullets.
antelopedundee, thank you for the link to Bruno Shooters, I will send them an email and ask how much it costs to obtain an export permit for bullets.
RockyMtnMT
Official LRH Sponsor
That's not even close. I'm surprised that they are listed for 10" twist. Even at higher altitudes they may shoot well but the rpm's will still not be high enough to give the best terminal performance.
Steve
I dont believe Sierra hasn't listed a twist rate for these. I called when they first came out in the summer and the tech I talked to said they were good to go for 10" twist. I bought 200 from Midway almost immediately and just now got to loading them
RockyMtnMT
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antelopedundee
Well-Known Member
You're welcome. I doubt if in the end it would be much cheaper that the nz$112.44 you have to pay now. You could try buying direct from Sierra, but they may have a minimum quantity that's more than you want.
For practice I'd try the
SIERRA 6.5 MM 130 GR. HPBT GAMEKING (100)
$91.16 (Inc Gst)
and use the Gamechangers for the actual hunt.
louis f
Well-Known Member
How far off of the rifling are you people seating your bullets for your best accuracy? Mainly for the 6.5 and 7MM. bullets. Just curious.
kiwikid
Well-Known Member
Thanks again antelopedundee. I found another company that must be importing Sierra Bullets rather than NZ Ammo Company. They have the 6.5 130 gr GC for $91.45 so I will buy a couple of boxes and see how they shoot through my 6.5-284 Norma. Hopefully before long I can report how they go on Red Deer.
When I talked to Sierra to get load data for the 28 Nosler, they recommended a jump of 2 thousandths but I dont know if that was for all 7mm cartridges.
gpo1956
Well-Known Member
.002 or .020?
lee31
Well-Known Member
I found best accuracy in my 6.5x55 with these bullets at 40 thousands jump.
