Bullet lengths for 7mm (.284) Sierra and Lapua

[happyshooting]

Hi folks, I was wondering if anyone has any bullet length information on a couple of 7mm bullets for me. I am interested in 2 potential bullets:

Sierra Tipped MatchKing 7mm 160 Grain (Polymer Tip)

Lapua Scenar-L 7mm 150Grn HPBT

 

I am trying to work out the bullet stability at a 1 in 9 twist rate, but very few manufacturers list the length.

Many thanks

Chris

[Nick 53]

Hi might be advisable to look up gun pimp or Laurie Holland, these people might be able to help.

You could make a dummy round up and then get OAL for each bullet weight .

Chap called gbal is another helpful person,

Cheers Nick

[Laurie]

The 150gn 7mm Scenar L is 1.34-inch give or take 10 thou'. Yes, it'll stabilise happily in a 9-twist barrel. Miller's twist rule calculates an Sg of 1.79 under standard conditions at 2,850 fps - which just happens to be what my mild 7mm-08 200/300 yard load gives it.

 

Take note though that by 7mm bullet standards, this design is very high drag / low BC, so it's a pretty piss poor choice for F-Class and similar even in mid-range matches. It is very well made and easy to tune, and I've had very good results with it at 300 yards. For 500/600 and beyond though I use the 160gn Sierra TMK in the 7-08 and yes, it stabilises happily too in a 9-twist barrel.

[happyshooting]

The 150gn 7mm Scenar L is 1.34-inch give or take 10 thou'. Yes, it'll stabilise happily in a 9-twist barrel. Miller's twist rule calculates an Sg of 1.79 under standard conditions at 2,850 fps - which just happens to be what my mild 7mm-08 200/300 yard load gives it.

 

Take note though that by 7mm bullet standards, this design is very high drag / low BC, so it's a pretty piss poor choice for F-Class and similar even in mid-range matches. It is very well made and easy to tune, and I've had very good results with it at 300 yards. For 500/600 and beyond though I use the 160gn Sierra TMK in the 7-08 and yes, it stabilises happily too in a 9-twist barrel.

 

Thanks for that info Laurie. That's really helpful. I was favouring the Sierra, so I will probably go with those. Many thanks! Chris