Sierra 155 2156

[TJC]

What are people's thoughts on this bullet vs lapua 155 or Berger 155.5?

Ta muchly

It is a significantly inferior bullet compared to the Lapua 155 or Berger 155.5 when measured by G7.

The G7 for these three are:
155 2156: 0.229
155 Lapua: 0.236
155.5 Berger 0.237

The harder part to answer is whether you can load and shoot them to a high enough standard to notice the difference in their ballistics.

[ovenpaa]

TJC Given the very small difference in G7 for the two and the significant price hoik between the Lapua and Berger I would agree and certainly would not shoot the Berger right now, in fact if there was parity of cost I would still work with the Scenar as it is such a consistent bullet to work with.

Welcome to the forum BTW.

[TJC]

Thanks for the welcome. Lapua is great if you can push them fast enough. I prefer a shorter barrel so struggle myself. The cost difference mentioned earlier is remarkable. I've just moved to the UK from the US where the difference between a box of 100 is just under 2.5 fine English pounds.

[John25]

Welcome to the UK, the forum, and the frustrating world of pounds for dollars shooting stuff.

[dromia]

Welcome TJC.

Why not introduce yourself on the new members forum?

[ovenpaa]

Thanks for the welcome. Lapua is great if you can push them fast enough. I prefer a shorter barrel so struggle myself. The cost difference mentioned earlier is remarkable. I've just moved to the UK from the US where the difference between a box of 100 is just under 2.5 fine English pounds.

I shoot mine through a 24" barrel most of the time and it does struggle at longer distances, 1100 is about maximum for me and I run out of elevation at 1200 unless it is a very warm day as my 'scope only goes to 13.1 mil.

[GazMorris]

The harder part to answer is whether you can load and shoot them to a high enough standard to notice the difference in their ballistics.

It's a good question. IMHO for TR it's probably marginal and you're only likely to be able to perceive a difference if you're a top flight shot (see my logic below) however for F-TR and F-Class you may be able to tell the difference more easily given the smaller achievable hold.

If we think about 1000 yards, with a good ammunition/rifle combo your average TR shooter probably holds over 2moa for a ten shot group*. A Palma Team shooter will hold 1 moa, maybe 3/4moa on a good day. The larger the basic group, the harder it is to realistically distinguish whether a wide shot is the result of an error by the shooter or a wind change. For example, if we consider our 2moa shooter, they will not reliably be able to perceive a wind change of less than 1 moa just by looking at where their shots fall**.

Now if we consider the difference between the Berger and the Sierra bullets, which works out a 0.5moa for 10moa wind change (as calculated using the excellent JBM Ballistics page at http://www.jbmballistics.com/) so is going to be less than 1/4moa for your typical 2-3moa wind change at 1000 yards, which just gets swamped by the group size.

Cheers,

Gaz

* Lots of people think they hold better than they actually do. They're generally (but not always) deluding themselves through a mixture of optimism, selective memory and bad plotting. The 1 moa figure comes from a careful examination of all of the GB plots from the 2007 Palma Match.

** This a common cause of people going outside the bullseye one side, making a wind change and immediately going out the other side. The first shot was actually just a wide shot in their group and not actually a wind change.