Bumping .308 from 167gr to 175gr?

[Shynloco]

Been shooting 167gr SMK HPBT in my .308 bolt gun. Great at 300yards, but seem less stable in high wind at 500meters, so plan to shoot 175gr (also SMK HPBT) at 500m in two days, to hopefully handle the wind better. No time to zero before shooting - so my question is, if I was consistently in the black at 500 with 167gr (but blowing all over the black), will I need much or any elevation adjustment shooting 175gr?

alamo,
FWIW, a shooting buddy of mine had a discussion with one of Sierra's bullet techs a few years back who told him the 168 Sierra HPTB was not designed for shooting over 300 yds when chasing better accuracy. For longer distances, he strongly recommended going to 175's and if you go even further (700 yds) go to an even higher weight Sierra bullet depending on which weight your particular rifle will shoot the best. So I'm not surprised that you found some variation and inconsistency once you got out over 300 with the 168 gr HPBT, let alone wind issues.

Alex

 

[Turbulent Turtle]

I should also point out that Sierra released last year the Tipped version of the 168SMK, among others. They also fixed the issue with the too sharp boat tail angle and it now performs as it should. I believe they call them TMK. Their site shows them available in .224 as the 69 and 77TMK; in .243 as the 95TMK; in .264 as the 130 TMK; in .284 as the 160TMK; and in .308 as the 125, 155, 168 and 175TMK. I would suggest that if you are restricted to Sierra bullets, those would be the ones at which to look for competition purposes.

 

[Medic505]

I have shot some of the 175 TMK's and they do shoot well. As a matter of fact, I won 500 of them at a match somewhere, so thank you Sierra for supporting F-Class!

 

[BOBC]

Many thanks for the kind words Denys. You put my wise crack into a better perspective.

Bob, Congratulations on making the bullet that won the 2009 worlds. Quite an honor, no doubt about it. But that was 2009. Compare those scores with scores from the 2013 worlds and I'm sure you'll see a huge difference. That said, I'd nearly bet that scores from 2013 probably won't win you much in 2017. F-Class is a fierce sport and if a shooter expects to shoot well, he or she has to be on the leading edge of technology. Your comment that I won't be shooting your bullets was spot on. I'll be shooting the highest BC bullet that I can get to shoot accurately. The last 2 records that we set in F-TR @1000 yards were shot with bullets of 200 grains or more. Like Denys said, if you can build a bullet that shoots with a 200 Berger hybrid or a 212 JLK BC wise, the F-TR world would beat a path to your door.

An interesting comment from Danny Biggs, who has won about everything there is to win in US F-Class. A couple of times.

P.S. BTW, my next F-Open build will adopt the .308 cartridge using 215's.

I do make a few bullets that have very high BC's but they not 30's. Ask Brian Litz. He mentioned them in one of his books. I've been told they have BC's in the sixes and sevens.

And to set the record straight, I said, "I'm sure it it won't be you that sets a new F-Class record with a 308". I would appreciate when someone quotes me they do it accurately. I also want to point out you're the person that wanted me to let him know when someone sets a World Record with a 308 and a bullet I made. I would be the last to know, so you're going to have to be on the mailing lists all match results world wide provided they post the components used by the competitors.

I don't have, nor do I want to have a web site highlighting my hobby. I've been retired the last 25+years. Bullet making is my hobby of 60 years, not my living. If a shooter asks me if I would hand make a custom bullet for him or her and I have the time and the right components, chances are I will.

If I've ticked off any of the forum members you have my apology. However, everything I've ever posted on the forum was the truth.

 

[Turbulent Turtle]

I'm sure it won't be you.
My bullets only reflect the user's marksmanship capabilities.
(snip)
FYI the last 3 matches he shot he did not shoot any nines. However, I do not or never did recommend a 308 Win for "F" class. But its a darn good over the coarse NRA High Power cartridge.

In post #11, you said the above, which I highlighted for you.

It's ok; you're not familiar with F-class and its two divisions; F-Open and F-TR. There are existing World Records in F-class, established with .308 bullets, and there will be more.
It's all good.

 

[Medic505]

Click to expand...
I'm sure it won't be you.
My bullets only reflect the user's marksmanship capabilities.

And to set the record straight, I said, "I'm sure it it won't be you that sets a new F-Class record with a 308". I would appreciate when someone quotes me they do it accurately

you can't even quote yourself accurately.........