Twist rate and bullet choice

[Kevin1990]

Building a 6br to shoot 500 yards and in. 99.9 percent would be done done at 300 yards and in. I've got the entire build figured out except barrel twist and bullet choice.

If you had a 6br what would be your go to bullet for 300 yards and in, and twist rate? Would it differ from your 500 yard choice?
Just looking to shoot smallest groups possible.

Looking at 95gr BIB?
Or 105 vld?

 

[Bill Norris]

1 -8 should work well for both bullets.

 

[Kevin1990]

Or a bullet in the 80s. I should have said

 

[Dgd6mm]

1-8 twist and roll with whichever bullets you care to shoot at distance.

 

[RegionRat]

@Kevin1990
Maybe give us an idea of the kind of shooting you like to do at those distances.

Sure, everybody wants the smallest groups possible.... but there is a difference between topics like varmints, field positions, F-Class, and Bench Rest for example.

Each of those buckets of shooting types would get you different answers as far as advice on the chamber neck prescriptions or the bullets.

A 1:8 twist covers a lot of ground. Right up to and including the 108 class but may or may not like the 115 weight class.

 

[Kevin1990]

@Kevin1990
Maybe give us an idea of the kind of shooting you like to do at those distances.

Sure, everybody wants the smallest groups possible.... but there is a difference between topics like varmints, field positions, F-Class, and Bench Rest for example.

Each of those buckets of shooting types would get you different answers as far as advice on the chamber neck prescriptions or the bullets.

A 1:8 twist covers a lot of ground. Right up to and including the 108 class but may or may not like the 115 weight class.

My apologies. I was thinking that when I wrote it, but of course didn't include it. It would be for f class. A club I found by me does an informal competition once or twice a month. The range is 300 yards, and that's the only one within about 4 hours of me that is longer than 200 yards.

So I'd just be shooting f open type shooting. I figured I wouldn't need that big a bullet?


Also, I am curious about the BIB flat base as opposed to other bullets that are boat tail, but I'm sure that could be a conversation for another post.

 

[RegionRat]

F-class club matches are typically 3 strings of 20 shots plus sighters, just depends on the club.

I would see if you can get a sample of all the ones you think you can later get in quantity and go run yourself a test, then stock up on your favorite. But...

I would keep in mind the amount of bullets you need for F-Class. The quantity is another big difference between F-Class and BR shooting, where you need a lot more for F-Class so those tend to come in the form of several boxes of 500 for a season.

If you find yourself only shooting a maximum of 300 yards, then you may find some of the flat base options will compete, but if not you can always fall back onto the known easy button which would be along the lines of the Berger 105 Hybrid (or Sierra 107 MK).

I would include something like the 105 Hybrid along with anything else you find just to get a baseline with something that tends to always work.

Randy makes excellent bullets from 65 to 104 grains. These are custom BR quality bullets but if you can afford to shoot them in F-Class there is no reason you can't.



300 yards is a little like a cross-over distance where the Flat Base bullet often overlaps with the boat tails. If you shoot where there are strong winds, you will want to test in wind to see what will work best for you. If you think you will spend much time beyond 300 or you will have winds most of the time, then try those BIB 104 BT or the Berger 105 Hybrid along with anything else you test.

More folks will come along with suggestions. Have fun and I'm in for the range report when you get it dialed in.

 

[marchx]

I made the same mistake you are planning to make: a built a 6br f-class rifle. I have 1:8 twist and shoot 105s and 109s hybrids.
It's theoretically a winning combination. Except it does not win in the wind. I was shooting a match last week and direction of 20 m/s wind was changing. My bullets landed on 3 o'clock and on 9 o'clock due to these rapid changes. There were no flags by the way. Unless you are a wind reading expert 6br currently is not a winning cartridge. And by the way the guy next to me was shooting 338lm with a brake. In my view F-open should be divided in sub-classes. It would make sense to compete against 6s and 6.5s. But not against .284s.

 

[jelenko]

shooting 338lm with a brake

How did he do?

 

[One Eye Pete]

Don’t over think it. For 300 to 500 yards a 6br shooting 103 to 109 gn. bullets out of an 8 twist barrel is a winning combination. The “easy tune” combination is a 108 Berger or a 107 SMK using approx. 30 gn. of Varget. This combination will even reach out to 800+ yards. Granted a 7mm will have an advantage at longer distances in the wind but at 300 the 6 br is a winner. At 100 yards you can always use an 80 gn. flatback bullet out of an 8 twist although a 12 twist might be very slightly more accurate. For versatility stay with the 8 twist. As far as bullets I have heard nothing but but good things about BIB bullets although I haven’t had the opportunity to shoot them. The other really good bullets that I have used are Barts. I have used Barts 105 gn bullets in my 6 br and loaded slightly jammed into the lands they shoot “lights out“ at 300 yards.
I live in SC and I know that one year Bart shot his 103 gn bullets out of a 6 bra at the Tackdrive. The conditions where so bad I wouldn’t have even taken my gun out of the case and he won against some really top notch shooters.
I have both a 6br and a 7mm 284 Shehane. For the type of shooting you are describing stick with the 6 mm it’s a lot cheaper to shoot and there are a lot more good bullets available.
As far as the reference above to a 338 LM having an advantage over a 6 br in the wind that is probably correct except not at an F-class or BR match because the muzzle break isn’t legal. Without that brake the shooter would be hurting pretty bad by the end of the match !!!!

 

[Kevin1990]

F-class club matches are typically 3 strings of 20 shots plus sighters, just depends on the club.

I would see if you can get a sample of all the ones you think you can later get in quantity and go run yourself a test, then stock up on your favorite. But...

I would keep in mind the amount of bullets you need for F-Class. The quantity is another big difference between F-Class and BR shooting, where you need a lot more for F-Class so those tend to come in the form of several boxes of 500 for a season.

If you find yourself only shooting a maximum of 300 yards, then you may find some of the flat base options will compete, but if not you can always fall back onto the known easy button which would be along the lines of the Berger 105 Hybrid (or Sierra 107 MK).

I would include something like the 105 Hybrid along with anything else you find just to get a baseline with something that tends to always work.

Randy makes excellent bullets from 65 to 104 grains. These are custom BR quality bullets but if you can afford to shoot them in F-Class there is no reason you can't.

View attachment 1433291

300 yards is a little like a cross-over distance where the Flat Base bullet often overlaps with the boat tails. If you shoot where there are strong winds, you will want to test in wind to see what will work best for you. If you think you will spend much time beyond 300 or you will have winds most of the time, then try those BIB 104 BT or the Berger 105 Hybrid along with anything else you test.

More folks will come along with suggestions. Have fun and I'm in for the range report when you get it dialed in.

Thanks for all the info! Sent an email over to bibullets, about the 95 and 104 for pricing. Waiting to hear back. If they are out of my price range I'll try some 107s and 105s in an 8 twist.