New to 6BR

[Kevin1990]

Well, I hope the end results are as good as my 6 Creed.

If you can shoot and tune a load like that with a 6CM, the 6br should be a cake walk. I burned out a 6 creed barrel. It was on my first ever custom rifle, and after that I switched to a 6br as you are doing. Loading and keeping the load in tune was night and day for me. I enjoyed the 6 creed, but after getting the 6br, I'll likely never go back, to anything else that's a barrel burner. I'll just keep having 6br variants chambered like I am now. 6br, 30BR, 6bra etc.

That said, 107 smk and varget with a CCI 450 primer in Lapua 6br brass shot the best for me. Surprisingly, Hornady 105bthp match shot about the same as the 107 smk. I could not get the 108eldm to shoot how I wanted, but I didn't give it the same attention as the 107 smk.

I use a redding FL die and then a mandrel to get my desired neck tension.


I plan on trying some N140 in the 6br soon and some berger 108bt.

 

[Kracken McGraw]

If you can shoot and tune a load like that with a 6CM, the 6br should be a cake walk. I burned out a 6 creed barrel. It was on my first ever custom rifle, and after that I switched to a 6br as you are doing. Loading and keeping the load in tune was night and day for me. I enjoyed the 6 creed, but after getting the 6br, I'll likely never go back, to anything else that's a barrel burner. I'll just keep having 6br variants chambered like I am now. 6br, 30BR, 6bra etc.

That said, 107 smk and varget with a CCI 450 primer in Lapua 6br brass shot the best for me. Surprisingly, Hornady 105bthp match shot about the same as the 107 smk. I could not get the 108eldm to shoot how I wanted, but I didn't give it the same attention as the 107 smk.

I use a redding FL die and then a mandrel to get my desired neck tension.


I plan on trying some N140 in the 6br soon and some berger 108bt.

What powder charges were you happy with on the Varget and 105-107’s?

 

[Kevin1990]

What powder charges were you happy with on the Varget and 105-107’s?

Id have to check my notes, but I believe I was shooting 29.2 gr. I had a NSS criterion barrel on a defiance tenacity, and it seemed to pressure out when I hit 30grs or came close to it, so I left it where it was. The 6br I have now is right at 30.0gr. Went up to 30.5 without any pressure on my kelbly atlas, but it shot so well at 30.0gr I decide to leave it. I have 1 pound of varget left, and then I think I may switch to N140, and see what happens.

 

[Kracken McGraw]

Id have to check my notes, but I believe I was shooting 29.2 gr. I had a NSS criterion barrel on a defiance tenacity, and it seemed to pressure out when I hit 30grs or came close to it, so I left it where it was. The 6br I have now is right at 30.0gr. Went up to 30.5 without any pressure on my kelbly atlas, but it shot so well at 30.0gr I decide to leave it. I have 1 pound of varget left, and then I think I may switch to N140, and see what happens.

Thanks, that sure helps. I am fixing to try Varget with those bullets, I think I will start at 28 for a seating test and then gradually work up on powder.

 

[ELR LVR]

I would interject, you will be wanting a 7.5 or 7 twist to stabilise the 110’s and up…
Were you using the 115 Dtacts in a 6BR or a 6CM?
I would think that there is just not enough powder capacity in the 6BR to make the 112-115’s perform, especially at a 1’000.
I would think that they would be falling subsonic by then…??
The 103’s that I used one year in F Open were real performers but struggled a bit once past 600 unless conditions were good as the heavier 6mm and larger bullets with the larger cases just bucked the wind better.
Using the mighty 6BR to 600yd now and then to the 7mm for longer distances these days just to keep the rest of the crew in line…
I did take out a club F Open with the 103’s but the planets were kind and the Dasher that was chasing me fell short that year…
Currently using Sierra 107”s again now that they come factory pointed and they are a bit more forgiving in the wind. Recent 500yd clean of 200.14 so they definitely are working well in the 1:8, 28”benchmark barreled Eliseo R5.

I respect your knowledge and experience
I should state, My experience in this particular thread may be relevent or not
but its free advice and can be ignored....
the cartridge I was using is a 6x284 / 8 twist / also almost always 2000 ft and above in elev.
With that said, I realize this thread was relating to a 6BR however....
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Relating to bullet choices - I was more stating my experience with those certain projectiles for 6mm
---- "in General for long range."
At 1000 if the wind blows, I prefer higher BC vs. a possibly more accurate bullet with less BC
.100 or more difference in BC is quite a bit where past 600 yds Higher BC usually translates to tighter groupings. Even if the 115's only shoot 1/4 MOA at 600, I've found they still hold that all the way out.
For something that travels slower than 3000 fps I would agree a faster twist than 1:8 would be more ideal.
Before 1:8 barrels became common and were rarely heard of, I used to shoot Sierra 107's in a 1:9 twist with great success out to 1 Mile. Velocity can increase SG a whole 0.10 on the scale.
Believe it or not I first started with the old Dtacs (Non-rebated boat tail) with my last 1:9 barrel and they shot extremely well at 1000 yds. (BC on the old 115's I believe was approx .563?)
I only went to a 1:8 because the New Dtacs raised the BC to .620 so I wanted some insurance of SG.
When I run the numbers I believe my SG is 1.42, which is "Theoretically" marginally stable but near enough to 1.5 which is inside the Theoretical "Comfortable" range.
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A comparison:
Running the slower 1:9 barrel in a 6x284 with 107 SMK's - Sg was approx 1.33
Which is what a 6BR would be Stability wise with a 1:8 barrel using the 115's
And as I mentioned, shot well out to a mile with that stability factor.
It doesn't make it less accurate you just have to correct the BC which would drop slightly from .620 to .588
.588 BC is still higher than a Sierra 107's BC
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So even
Being on the edge of stability, Also depends on if its cut rifled or not, cut rifled have been proven to stabilize better when the same twist barrel being button rifled may not, since a cut rifled barrels twist is more true and consistent to its twist rating throughout its full length, without skipping.
IE; it may shoot perfect in a 1:8 cut barrel, yet throw in sideways from a 1:8 buttoned barrel
(Bartlein has proven this, Per Frank Green)
So with a buttoned barrel a guy would have to increase his twist rate at least another 0.5 faster to compensate. Which could be why some run a 1:7.5 and others may run a 1:8 and get away with it.
I would run faster twist too except then you run the risk of bullet failure with the faster twist.
And I already experience that with some bullets so don't want to limit my choices even further.
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Sierra 107's are a Solid choice too, great bullet
I go Sub at around 1900 yds with 115's at my Elevation.
115's still hold approx 1/4 MOA even after going Sub if you repeat the same wind condition.

 

[ELR LVR]

One other thing to point out with high B.C.
I've talked to some people who might choose a custom bullet that may be more consistent from lot to lot
---Yet has Lower BC
There is a tradeoff with a more accurate bullet, with less BC at a certain point/distance downrange.
vs
A less Accurate bullet but with Higher BC
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The more accurate bullet with less BC .....will slow down faster before reaching the target
Lets say 8% velocity loss per 100 yds vs 4% velocity loss per every 100 yds
So the faster a bullet slows down, simply due to more hang time in the air
---- the wind will push it around more, even if the group started off more accurately at 100 yds
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Whereas, the Less accurate Higher BC bullet, retains more velocity the further out it travels
So has less flight time, gets to the target faster, so is blown around less by the wind simply by virtue of reduced TOF.
Which in this tradeoff, the less accurate / Higher BC bullet, is actually more accurate the further the distance is.

BC doesnt just mean bucking the wind, but also means more retained velocity downrange
More retained velocity or less velocity Loss = Less flight time
So its not so much bucking the wind that is helping us in dispersion long range
but reduced flight time to target, Spending less time in the air means less time the wind has to push us around