24hourcampfire.com
Previous Thread
Next Thread
Print Thread
Hop To
180 ELD in 7-08 with 9.5 twist #14638191 03/06/20
Joined: Dec 2007
Posts: 1,018
IDMilton Offline OP
Campfire Regular
OP Offline
Campfire Regular
Joined: Dec 2007
Posts: 1,018
I'm not sure what forum to put this in, but since this is a long range bullet, I'll put it here.

When I read about this bullet I thought it would be fun to try, but since my Tikka 7-08 is a 9.5 twist, I didn't think it would stabilize. But then Sportsmans had one box on the shelf, so I thought I'd give them a try just for grins.

Today I got out to shoot, but only at 100 yards. I was at 5k feet and usually shoot at that elevation. I started with Hunter. The gun didn't like them at all. Then I tied 4451. As I worked up, it got better. 43 grains in my Lapua cases is REALLY compressed at 2.83. But it shot four into about .7. (My rifle has a long throat, don't copy my loads for safety reasons, etc.) I know I need more rounds in the group, but this is the first time out and I was trying to find pressure/speed. I was at 2530 fps. I am going to load up more at 43 again, 43.2, 43.4, and see what it does and if it is repeatable.

Do you more experienced guys think the groups will fall apart at long range? Or, because of the slower twist, do I just plan on a lower BC?

I know I should just go try it at long range, but the place I usually shoot long is still snowed in for at least another month. so I'll just have to wait for the snow to melt to check for myself!

As an aside and I know everyone knows this, but my Tikkas are just so easy to load for.. .


The never-ending flight
Of future days.
Paradise Lost. Book ii. Line 221
BP-B2

Re: 180 ELD in 7-08 with 9.5 twist [Re: IDMilton] #14638247 03/06/20
Joined: Mar 2006
Posts: 11,347
Jordan Smith Offline
Campfire 'Bwana
Offline
Campfire 'Bwana
Joined: Mar 2006
Posts: 11,347
It’ll stay stable, but the BC value will take a hit. Enter your data in the JBM stability calculator online, and plan on about a 3% decrease in BC for every 0.1 under 1.5 in your SG value.

Re: 180 ELD in 7-08 with 9.5 twist [Re: IDMilton] #14638252 03/06/20
Joined: Feb 2009
Posts: 3,855
J
joshf303 Offline
Campfire Guide
Offline
Campfire Guide
J
Joined: Feb 2009
Posts: 3,855
From my experiences...yes. The juice wasn’t worth the squeeze even in a 8.5 twist at 2600ish.

Re: 180 ELD in 7-08 with 9.5 twist [Re: IDMilton] #14639547 03/07/20
Joined: Dec 2007
Posts: 1,018
IDMilton Offline OP
Campfire Regular
OP Offline
Campfire Regular
Joined: Dec 2007
Posts: 1,018
So I used the stability calculator and ended up with 1.418. I don’t know if it is true, but I read online that the bullets actual Bc is about .7 from Brian Litz. If that is true and I am losing 3%, there is only an inch or two less wind at 800 yards than my normal 162 ELD x load.

However, if the claimed BC numbers are correct, it beats my old load by about 6 inches and would be worth it to me. Do you guys think the claimed BC is accurate, or would the Litz number Be more realistic?

This may be a case like you mentioned above where the juice won’t be worth the squeeze. Oh well, it was a nice day to get out yesterday


The never-ending flight
Of future days.
Paradise Lost. Book ii. Line 221
Re: 180 ELD in 7-08 with 9.5 twist [Re: IDMilton] #14639618 03/07/20
Joined: Feb 2002
Posts: 5,463
K
keith Offline
Campfire Tracker
Offline
Campfire Tracker
K
Joined: Feb 2002
Posts: 5,463
Try R#17

IC-A

Re: 180 ELD in 7-08 with 9.5 twist [Re: IDMilton] #14639689 03/07/20
Joined: Mar 2006
Posts: 11,347
Jordan Smith Offline
Campfire 'Bwana
Offline
Campfire 'Bwana
Joined: Mar 2006
Posts: 11,347
The 0.401 G7 BC value has been dead on for me in multiple rifles out to 1600 meters. My calculations based on velocity drop measured from 0-100 meters via LabRadar seem to verify this.

Re: 180 ELD in 7-08 with 9.5 twist [Re: IDMilton] #14644052 03/08/20
Joined: Dec 2007
Posts: 1,018
IDMilton Offline OP
Campfire Regular
OP Offline
Campfire Regular
Joined: Dec 2007
Posts: 1,018
So would I take 3% of 401, 389, and enter that as the G7 number? I just looked at the Hornady site where it lists the bc for the eld bullets at different speeds. If I look at the Mach 2 speed and the two twist rates listed and take a guess at what a 9.5 twist would be, I get about 360

https://www.hornady.com/support/ballistic-coefficient


The never-ending flight
Of future days.
Paradise Lost. Book ii. Line 221
Re: 180 ELD in 7-08 with 9.5 twist [Re: IDMilton] #14644212 03/08/20
Joined: Mar 2006
Posts: 11,347
Jordan Smith Offline
Campfire 'Bwana
Offline
Campfire 'Bwana
Joined: Mar 2006
Posts: 11,347
I would use the 0.389 value and tweak from there to match actual field results.

Re: 180 ELD in 7-08 with 9.5 twist [Re: IDMilton] #14644347 03/08/20
Joined: Dec 2007
Posts: 1,018
IDMilton Offline OP
Campfire Regular
OP Offline
Campfire Regular
Joined: Dec 2007
Posts: 1,018
Thanks, now I just need the roads to open!


The never-ending flight
Of future days.
Paradise Lost. Book ii. Line 221
Re: 180 ELD in 7-08 with 9.5 twist [Re: IDMilton] #14671719 03/17/20
Joined: Nov 2004
Posts: 4,318
B
Burleyboy Offline
Campfire Guide
Offline
Campfire Guide
B
Joined: Nov 2004
Posts: 4,318
Damon, they shoot great in my 9 twist 28 bowler but my velocity is a lot higher. I'm still shooting up my stash of 162 amaxes in my 7.08.

Bb

IC-B

Re: 180 ELD in 7-08 with 9.5 twist [Re: IDMilton] #14678890 03/18/20
Joined: Dec 2007
Posts: 1,018
IDMilton Offline OP
Campfire Regular
OP Offline
Campfire Regular
Joined: Dec 2007
Posts: 1,018
BB
Man do I miss the shooting at the Rexburg range and out in the BLM west of the interstate. Everything, literally, in this valley is private. The National forest is too thick to shoot long and we have to drive about 45 or 50 minutes To shoot across canyons and we can’t do that till the snow is gone. And setting up the targets is more of a pain. I didn’t appreciate the shooting in SE Idaho until l moved!
I shot again just at 100 to confirm things and at this range anyway things still look really promising I’ll stretch it out when I can to make sure things stay stable


The never-ending flight
Of future days.
Paradise Lost. Book ii. Line 221

Moderated by  RickBin, SYSOP 

RR1
Who's Online Now
108 registered members (2ndwind, 444Matt, 10gaugemag, 280man, 35, 19 invisible), 1,076 guests, and 650 spiders.
Key: Admin, Global Mod, Mod
RR2/3










Fish & Game Departments | Solunar Tables | Mission Statement | Privacy Policy | Contact Us | DMCA
Hunting | Fishing | Camping | Backpacking | Reloading | Campfire Forums | Gear Shop
Copyright © 2000-2020 24hourcampfire.com, Inc. All Rights Reserved.
 
Powered by UBB.threads™ PHP Forum Software 7.7.3
(Release build 20190728)
PHP: 7.3.16 Page Time: 0.047s Queries: 14 (0.003s) Memory: 0.8141 MB (Peak: 0.9163 MB) Data Comp: Zlib Server Time: 2020-04-04 08:32:11 UTC
Valid HTML 5 and Valid CSS