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I just bought a couple hundred 155gr Lapua Scenars based on the higher published BC they have over the 175gr SMKs. The 175gr SMKs seem to be the standard for long distance competition but it seems the Lapua Scenars have the edge with higher BC and velocity. Anybody have experience to back up this published data?
Looking those up in Bryan Litz's book, the 175SMK actually has a slightly better measured BC than the 155 Scenar. However, the higher velocity that the 155 should be able to get would offset that small advantage.
The 155's also have less recoil and less MOA to distance, my favorite bullet weight of the 308 family. I just got in 1000 scenars and plan to shoot a whole bunch this summer.
On paper, the 155's are fine. They are girly girl rounds for target shooting on paper.
On live targets, the 175's actually can do something when they get there. Application is everything.
Bryan Litz's Book? I looked it up and it looks like that book is exactly what I was asking for. I use the info. posted on http://www.frfrogspad.com/bcdata.htm which I believe is the same data used in QuickLoad/QuickTarget. I use these published values to make determinations on which bullets to try. It just seemed that some of the published values are hard to swallow.Quote:
Originally Posted by js223
Lapua .308 155gr scenar: published BC = 0.508
Sierra .308 175gr MK: published BC = 0.505
Can you publish the experimental values from the book for these two bullets? Does anybody know of a site/thread that has published these experimental values obtained by Bryan Litz?
id shoot whichever ur gun groups better with. my 308s dont show much of a preference, other than my m1a, which prefers scenars. i can tell ya the scenar at 2900ish outta my rifle will drop 28 moa @ 1k, vs 38( i think it was) w my best 175smk load. windage was slightly better w the scenars as well. imho the 308 cant push the bigger bullets fast enough to really take advantage of them. but, if ur gun really likes them, usem.
175gr SMK: G7 BC = 0.243, G1 BC = 0.475
155gr SMK (#2156 pointed): G7 BC= 0.229, G1 BC = 0.449
155gr Lapua Scenar: G7 BC= 0.236, G1 BC=0.462
The G1 BC's are averaged for 3000fps, 2500, 2000 and 1500fps in Bryan's book. Manufacturers often cite the G1 BC for 3000 fps only, which gives a false impression versus what people experience.
Thanks for the info.! I'm going to buy Bryan's book. I'm really more interested in the G7 values, now.
You are right on the mark!! For a .308...and a 175 gr. SMK....3000 fps is north of optimistic by a fair stretch.Quote:
Originally Posted by johndoe3
Wayne