7mm-08 with 180 VLD- doable?

ChadTRG42

Gunny Sergeant
Full Member
Minuteman
Jan 22, 2007
3,338
7
57
Dallas, Texas
www.dallasreloads.com
Can you seat a 180 Berger VLD in a 7mm-08 case to about ~2.840"-2.860" and the ogive not go below the case neck? I was curious if this would work feeding from an AI mag and the bullet be out far enough to touch the lands and still feed from a mag?
 

kombayotch

Gunny Sergeant
Full Member
Minuteman
Sep 20, 2007
1,852
42
Re: 7mm-08 with 180 VLD- doable?

You can figure this out mathematically:

length of bullet below neck/shoulder = bullet length - neck length - (COAL - case length)
= 1.525 - 0.284 - (2.860 - 2.035)
= 0.416

Numbers taken from Lyman 49th and Bryan Litz's book.
 

steve123

Lt. Colonel
Full Member
Minuteman
Mar 16, 2008
9,233
1,821
none of your business
Re: 7mm-08 with 180 VLD- doable?

Chad,I wanted to add an additional question. What velocities would one expect out of a 27" barrel?

Steve
 

kombayotch

Gunny Sergeant
Full Member
Minuteman
Sep 20, 2007
1,852
42
Re: 7mm-08 with 180 VLD- doable?

Sorry, you said ogive above neck...

Ogive starts at 0.734 above the base of the bullet. So:

0.734 - 0.416 - 0.284 = 0.034

It's positive, so it's still above the case mouth.
 

ChadTRG42

Gunny Sergeant
Full Member
Minuteman
Jan 22, 2007
3,338
7
57
Dallas, Texas
www.dallasreloads.com
Re: 7mm-08 with 180 VLD- doable?

Nice- Thanks, K! If you trim to minimum length, then you'll be .044" above ogive. There's not a lot of room to chase the lands though. That's pretty close. At 2.860", I'm at mag length with the metal front plate still in the mag. Thanks!

Chad
 

ChadTRG42

Gunny Sergeant
Full Member
Minuteman
Jan 22, 2007
3,338
7
57
Dallas, Texas
www.dallasreloads.com
Re: 7mm-08 with 180 VLD- doable?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: steve123</div><div class="ubbcode-body">Chad,I wanted to add an additional question. What velocities would one expect out of a 27" barrel?</div></div>
Should be around 2600-2650.
 

kombayotch

Gunny Sergeant
Full Member
Minuteman
Sep 20, 2007
1,852
42
Re: 7mm-08 with 180 VLD- doable?

I see the appeal of it, the BC is listed as 0.659 in Bryan's book. It is the highest BC 7mm bullet listed.

Although, the 175 SMK is listed at 0.639. It will probably be very close in ballistics and will be far more tolerant of jump. Its only 1.453" long, so you will also gain some case capacity and the ogive will be farther out.

I highly recommend getting Bryan's book if you haven't already. It lets you compare the ballistics of different cartridges with different bullets apples-to-apples with BCs that were derived in the same way.

Here's a nice example:

6.5-284 139 Lapua Scenar (BC=0.557) 2970 fps muzzle
1000 yards: -274" drop, 70" wind (10 MPH)

260 Rem. 140 JLK (BC = 0.639) 2820 fps. muzzle
1000 yards: -286" drop, 64" wind (10 MPH)

Your 7mm VLD with 2600 fps muzzle
1000 yards: -341" drop, 70" wind (10 MPH)

All three are the same as far as wind drift goes. The 260 and the 6.5-284 are equal in practical terms (in this case). This is why there is more to long range ballistics than just caliber and barrel length. A simple bullet choice can obliterate any advantage the "better" caliber/setup is perceived to have.

Really, Bryan's book is a Godsend for doing this type of analysis. And I have verified enough of his BC's myself to be confident in his work.
 

Onemoretime

Gunny Sergeant
Full Member
Minuteman
Sep 1, 2007
1,249
2
San Diego, CA
Re: 7mm-08 with 180 VLD- doable?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kombayotch</div><div class="ubbcode-body">
Here's a nice example:

6.5-284 139 Lapua Scenar (BC=0.557) 2970 fps muzzle
1000 yards: -274" drop, 70" wind (10 MPH)

260 Rem. 140 JLK (BC = 0.639) 2820 fps. muzzle
1000 yards: -286" drop, 64" wind (10 MPH)

Your 7mm VLD with 2600 fps muzzle
1000 yards: -341" drop, 70" wind (10 MPH)
</div></div>

How much better would it be if it were a straight .280/7mm-06?
 

kombayotch

Gunny Sergeant
Full Member
Minuteman
Sep 20, 2007
1,852
42
Re: 7mm-08 with 180 VLD- doable?

7mm VLD with 2800 fps muzzle
1000 yards: -287" drop, 62" wind (10 MPH)
 

Onemoretime

Gunny Sergeant
Full Member
Minuteman
Sep 1, 2007
1,249
2
San Diego, CA
Re: 7mm-08 with 180 VLD- doable?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kombayotch</div><div class="ubbcode-body">7mm VLD with 2800 fps muzzle
1000 yards: -287" drop, 62" wind (10 MPH) </div></div>

That's pretty bitchin... 27" barrel? Or?
 

Austan

Absolved from obedience
Full Member
Minuteman
  • Nov 27, 2007
    1,633
    1,224
    Spooner, Wisconsin
    Re: 7mm-08 with 180 VLD- doable?

    I've been really enjoying Brians book since getting it last week.

    Carry on.
     

    kombayotch

    Gunny Sergeant
    Full Member
    Minuteman
    Sep 20, 2007
    1,852
    42
    Re: 7mm-08 with 180 VLD- doable?

    The velocity was just a QL approximation with the 180 VLD bullet and whatever defaults it gave for 280 Rem. Wasn't the highest velocity generated, about 50 fps less.
     

    Onemoretime

    Gunny Sergeant
    Full Member
    Minuteman
    Sep 1, 2007
    1,249
    2
    San Diego, CA
    Re: 7mm-08 with 180 VLD- doable?

    I'm thinking about building either a 7-08 or 7-06 since I have a lot fo .308 and 30-06 brass.
     

    ChadTRG42

    Gunny Sergeant
    Full Member
    Minuteman
    Jan 22, 2007
    3,338
    7
    57
    Dallas, Texas
    www.dallasreloads.com
    Re: 7mm-08 with 180 VLD- doable?

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Buzzsaw</div><div class="ubbcode-body">Chad, what's got byou building a 7mm-08. I love the cartridge. </div></div>
    Hey Buzz,

    Nothing really. I like the round also, and was curious if the 180 VLD would fit in it. I know it's a long bullet. With it's high BC, if you could push it fast enough and seat it on the lands, I think it would be a good long range round.