Gobears16
Well-Known Member
What's the conclusion on 6.5 PRC twist rates? This gun will be used from sea level to 9500ft. Planning on 147eldm and hopefully heavier when the start coming out..7, 7.5, or 8?
PRC twist rate 7,7.5,8?
- Thread starter Gobears16
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codyadams
Well-Known Member
I would do 7.5 twist. When I contacted Berger, they said the 14l56 is designed around a 7.5 twist, but will work with an 8 twist. A 7.5 would get you the 156, the sierra 150, will shoot the 147 good, also.
codyadams
Well-Known Member
I did a 7.5 twist in a .264 wm for shooting the 156. I also shot the 147's in it, they also did great.
Havoc
Well-Known Member
Just my opinion, I'd go 1/7.5. Berger is coming out with the 156 gr EOL says you need a minimum of 1/8 to stabilize.
https://bergerbullets.com/new-berger-6-5mm-156-grain-eol-elite-hunter/
https://bergerbullets.com/new-berger-6-5mm-156-grain-eol-elite-hunter/
lancetkenyon
Well-Known Member
With sea level and up, and running a 147, and possibly moving up, I would go 1:7.5" at least.
The new 156 Berger Elite says "minimum 1:8" twist....but that is not the "optimal" twist rate. Run the numbers.
If you can get them to 3020fps, even at 30°F and sea level, you are still at 1.58SG. Fully stable, albeit not by a ton. Going to a 1:7" would bump SG to 1.82. 1:8" isn't going to cut it.
I run a 1:7.5" in my new 6.5SS, and the 156s are shooting phenomenally out of it.
The new 156 Berger Elite says "minimum 1:8" twist....but that is not the "optimal" twist rate. Run the numbers.
If you can get them to 3020fps, even at 30°F and sea level, you are still at 1.58SG. Fully stable, albeit not by a ton. Going to a 1:7" would bump SG to 1.82. 1:8" isn't going to cut it.
I run a 1:7.5" in my new 6.5SS, and the 156s are shooting phenomenally out of it.
AFraser
Well-Known Member
I wish I'd gone 1:7.5" when I re-barrelled by Creedmoor, given the number of heavier bullets appearing that are marginal with a 1:8. I don't think there's a downside.
Creedmoor shooter
Well-Known Member
I would do a 7.5 twist. With these awesome high BC 6.5 bullets that keep coming you'll be glad that you did. When I rebareel my creed it will be a 7.5 twist if I stay 6.5.
I went with 1:7" on my .264 WM also for the 156 but have yet to load and shoot them yet.
alf
Well-Known Member
My 1st one I did an 8 twist, worked great at my 1500 ASL with 150 SMK's.
Sold that one and built another with a Bartlein 7.25" twist, but have settled on the 140 VLD's for now. Not sure if I'll pursue the 156's or not.
Sold that one and built another with a Bartlein 7.25" twist, but have settled on the 140 VLD's for now. Not sure if I'll pursue the 156's or not.
sable tireur
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You can actually get it to the point of splitting hairs if that's what you're looking for.
The 140's need a 1:8"
The 153 A-Tip needs a 1:7.75"
The 156 Berger should have a 1:7.5"
I'm using the 7.75" because all of the testing I've done with 156 in the 7.5" leads me to say that they are not worth the investment for my applications. Others will disagree but after several hundred bullets, there are better choices. The 153 A-Tip is showing some promise but I haven't killed anything yet. It's up for use in the 7.75".
I'd go all the way to 1:7 twist. I'm really starting to like the Hammer bullet line. The 6.5, 137gr Hammer Hunter looks really appealing (requires 1:7) if you have a bigger cartridge like a PRC.
*Not the BC of Berger and Hornady offerings, so I get the appeal to the other high BC options out there. I'm also a Berger/Hornady fan and know a 1:7 wouldn't hurt with the 140, 143, 146, 150, or 156gr offerings ... So why not???
*Not the BC of Berger and Hornady offerings, so I get the appeal to the other high BC options out there. I'm also a Berger/Hornady fan and know a 1:7 wouldn't hurt with the 140, 143, 146, 150, or 156gr offerings ... So why not???
SwampDog13
Well-Known Member
If you have any intentions of running the monos then I'd go 7", calling it a day with the 156s the 7.5" would be my pick.
My saum has an 8 twist and it handles the 156s just fine at sea level but it's also 90+ degrees out right now and I have not had the opportunity to shoot them in the cold. If I was to do it again I would have it spun up with a 1-7.5".
My saum has an 8 twist and it handles the 156s just fine at sea level but it's also 90+ degrees out right now and I have not had the opportunity to shoot them in the cold. If I was to do it again I would have it spun up with a 1-7.5".
I'm going with the 7.5 on a prc build which is in the works now.
I'm targeting the 156 which I have in hand now but should have no trouble shooting down to the 140's allowing me to shoot the hornady factory 143 and 147's if needed in a pinch. My rifle may not be done until October so this is likely the direction I'll take for deer season. My Smith is reporting excellent results from his prc builds with factory hornady as I'm sure most are. Most of his are running 7.5' which he's built a bunch of this year.
I'm targeting the 156 which I have in hand now but should have no trouble shooting down to the 140's allowing me to shoot the hornady factory 143 and 147's if needed in a pinch. My rifle may not be done until October so this is likely the direction I'll take for deer season. My Smith is reporting excellent results from his prc builds with factory hornady as I'm sure most are. Most of his are running 7.5' which he's built a bunch of this year.
Nomosendero
Well-Known Member
Is there a downside to going 1-7 using 140 gr. and heavier or long mono's, if not why not go 1-7, who knows a 160-162 gr. may be next.
