Keep sg between 1.5-1.8 for optimal accuracy. There's a reason why benchrest guys run bare minimum twist to keep bullets stable at their atmospherics. Are we shooting elr of mile plus? Twisting the **** out of things is only necessary to keep flight characteristics as a bullet goes into transonic velocities. Totally unnecessary for a rifle used to hunt. 6.5mm target ranges out to 1400y, killing deer 1000y, killing larger bodies like elk 700-800y 8tw will do yo just fine, bartlein did a run of 7.75s too, I have one in 65prc.
6.5 prc build?
- Thread starter volunteer06
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volunteer06
Well-Known Member
So if I was to hit 3000fps the rpm would 308,571. Which may be just enough to blow bullet apart. Also with all the talk on here I do plan to try some hammers some day but Berger will be the starting go to. Does Berger go by the 300,000 rpm or is that just a standard with all cup and core? Also appreciate the box suggestions.
I do plan on building this on a mid length action as well.
I do plan on building this on a mid length action as well.
You won't blow bergers or Sierras unless you running super fast twist and high speed. Horandy eld have a pretty thin jacket and are known to come apart from too many rpms. I mean I've ran 140 Bergers through 8tw at 3200, no failure, 109s though 7tw at 3000 no failure. 142smk though 8tw at 3180 no failure. 215 Bergers through 9tw at 3150 no failures. However 180eldm though 8tw at 3k and we were getting failures, 147eldm over 3100 from 7.5tw failures. However their 75eldm is tough, I've ran em to 3600 from an 8tw and never observed the gray loosh mid flight.
Trapperuss
Member
looking at your 308 pc in classifieds what kind of magazine is it blind,box,drop plate etc also is the barrel threaded sorry long time lurker but can't reply in classifieds cause insufficient post count.
Sent you a PM
volunteer06
Well-Known Member
Sounds like may need to back up and maybe go with a bartlein 7.5. I live at elevation less than 1000' hunting trips would be higher and that is what this gun will be for. I do not plan to run any 140s just 156 or possibly a mono so it seems I may be borderline with a 7. I appreciate all the input. Also thanks for the box suggestions I will be ordering one of those recommendations
acourvil
Well-Known Member
I've been running a 6.5 PRC with 1:7 barrels for a couple of years now. I shoot mainly 153.5 Bergers at ~3030 and have never had a problem; I'm sure the 156 Bergers will also be fine. In the past, I did have a problem with Hornady 156gn A-Tips blowing up, and have heard from others that the 147ELDs also have problems. And if you want to shoot the solids later, the faster twist will be a benefit.
BrentM
Well-Known Member
Many have said it, should be good with the heavies but the one thing it will work well with is the solids. I have 7.5 and 8 twist and both work great with 156 but a solid would be a potential issue.
You'll be just fine with a 7twist. Run the heavies with no worry.
I went with a 31" Bartlien 5R LH 1:8.5 to 1:7.5 gain twist. It works great with 153.5 and 156 grain Bergers, .3 moa at 100 yards. 64 grains of N570 gives me 3311 fps average.
Litehiker
Well-Known Member
My Browning 6.5 PRC Browning X-Bolt Pro has a 1:7 twist in a factory lapped stainless steel barrel.
volunteer06
Well-Known Member
Per a phone call to Berger they said it would be no issue. If I was running that setup in a 6.5x300 weatherby or somethin where velocity was 3200 fps it would be an issue.
snox801
Well-Known Member
Wouldn't he be limiting himself more on bullet choices with an 8 then?
Not being able to shoot any of the long monos? And I doubt he would be over spinning a 156 or even 147 eld in a 1:7
