6br twist

[Sneedvegas01]

building my first gun to shoot in a local match, I’ve pretty much decided on the 6br.. It’s a 300 yard group match, what twist barrel would you guys recommend? What weight bullet is generally the best for 300 yards? Thanks for all the help, be easy on me I’m a little green lol

 

[blowemup]

building my first gun to shoot in a local match, I’ve pretty much decided on the 6br.. It’s a 300 yard group match, what twist barrel would you guys recommend? What weight bullet is generally the best for 300 yards? Thanks for all the help, be easy on me I’m a little green lol

An 8 twist will enable you to shoot 95’s all the way up to 108’s

 

[byrddog]

Agreed.....8 twist. Blowemup is spot on.

 

[Sneedvegas01]

Thanks guys. I had a 8 twist in mind but I had a guy recommended a 10 twist to me the other day. I like the idea of being able to shoot up to 108’s

 

[blowemup]

As for which pill is best !! Well you will not know until your Smith has chambered & fitted the barrel & you have tried a half dozen different ones.
Test over flags on a good day & you’ll soon see what’s worth playing around with.

 

[Lefty Trigger]

I got an 8 twist but two guys in our club that shoot short range only have 12 twist and shoot light bullets.

 

[Texas10]

8 twist, 107 SMK is a good start.

 

[farmerjohn]

I have barrels in 14, 12, 10, and 8 twist and the 10 won't stabilize the VLD bullets that I think you will end up shooting because of their ability to stand up to the wind....
Farmer

 

[Sneedvegas01]

I have barrels in 14, 12, 10, and 8 twist and the 10 won't stabilize the VLD bullets that I think you will end up shooting because of their ability to stand up to the wind....
Farmer

So your saying you would recommend the 8 twist?

 

[gunsandgunsmithing]

Here's a chart I made with some common 6mm bullets and velocities. At ranges of 100-about 400, accuracy trumps everything else, so you have to test to know what WORKS best for you. I've found that 80-90 gr bullets are working very well out to those distances for me. Much beyond there and bc of the heavier bullets starts to overcome the difference in the raw accuracy edge of the lighter ones. Of course there will be exceptions and people that will claim the 105 class bullets in an 8 twist are great..but they either don't show up or don't shoot well enough to be competitive at short range when they do actually show up at a match. So, this is what I have found to be the best range of bullet weights for ME in a 6 Grendel and 6BR! YMMV.
Sorry about the formatting when I paste it here.


68s

Range Elevation Elevation Elevation Windage Windage Windage Time Energy Vel[x+y]
(yd) (in) (MOA) (MIL) (in) (MOA) (MIL) (s) (ft.lbf) (ft/s)
0 -1.50 0.00 0.00 0.03 0.00 0.00 0.00 1797 3450
100 -0.01 0.01 0.00 1.00 0.95 0.28 0.09 1409 3055
200 -2.26 1.08 0.31 4.10 1.96 0.57 0.20 1096 2694
300 -9.34 2.97 0.86 9.74 3.10 0.90 0.32 842 2361
400 -22.71 5.42 1.58 18.43 4.40 1.28 0.45 636 2052
500 -44.40 8.48 2.47 30.87 5.89 1.71 0.61 472 1768
600 -77.31 12.30 3.58 47.85 7.62 2.22 0.79 347 1515


80's
Range Elevation Elevation Elevation Windage Windage Windage Time Energy Vel[x+y]
(yd) (in) (MOA) (MIL) (in) (MOA) (MIL) (s) (ft.lbf) (ft/s)
0 -1.50 0.00 0.00 0.03 0.00 0.00 0.00 1935 3300
100 0.00 0.00 0.00 0.89 0.85 0.25 0.10 1571 2973
200 -2.45 1.17 0.34 3.63 1.73 0.50 0.20 1267 2671
300 -9.80 3.12 0.91 8.55 2.72 0.79 0.32 1012 2387
400 -23.29 5.56 1.62 16.02 3.82 1.11 0.45 799 2121
500 -44.55 8.51 2.47 26.52 5.06 1.47 0.61 623 1873
600 -75.78 12.06 3.51 40.62 6.46 1.88 0.78 481 1645





90gr bt
Range Elevation Elevation Elevation Windage Windage Windage Time Energy Vel[x+y]
(yd) (in) (MOA) (MIL) (in) (MOA) (MIL) (s) (ft.lbf) (ft/s)
0 -1.50 0.00 0.00 0.03 0.00 0.00 0.00 1983 3150
100 -0.01 0.01 0.00 0.66 0.63 0.18 0.10 1712 2927
200 -2.59 1.23 0.36 2.64 1.26 0.37 0.21 1471 2713
300 -9.90 3.15 0.92 6.13 1.95 0.57 0.32 1256 2507
400 -22.76 5.43 1.58 11.31 2.70 0.78 0.45 1067 2310
500 -42.16 8.05 2.34 18.39 3.51 1.02 0.58 900 2122
600 -69.30 11.03 3.21 27.65 4.40 1.28 0.73 754 1942





105vld
Range Elevation Elevation Elevation Windage Windage Windage Time Energy Vel[x+y]
(yd) (in) (MOA) (MIL) (in) (MOA) (MIL) (s) (ft.lbf) (ft/s)
0 -1.50 0.00 0.00 0.03 0.00 0.00 0.00 2029 2950
100 0.00 0.00 0.00 0.58 0.55 0.16 0.11 1801 2779
200 -3.02 1.44 0.42 2.27 1.08 0.32 0.22 1592 2613
300 -11.14 3.54 1.03 5.23 1.66 0.48 0.33 1403 2453
400 -25.05 5.98 1.74 9.58 2.29 0.66 0.46 1231 2298
500 -45.55 8.70 2.53 15.44 2.95 0.86 0.60 1076 2148
600 -73.60 11.71 3.41 22.99 3.66 1.06 0.74 937 2004

 

[farmerjohn]

So your saying you would recommend the 8 twist?

Yes, one of my varmint rifles is a 6MM with a 10 twist Kreiger that shoots under 1/2" will shoot with just about any good bullet up to and including some of the shorter flat base 100gr hunting bullets. I have tried the 103, 105, and 108 VLDs and at 100yds the group opens up to around 1&1/2" and gets worse the farther out you go quickly. The people in the above post are telling you right....
Farmer

 

[Evlshnngns]

Here's a chart I made with some common 6mm bullets and velocities. At ranges of 100-about 400, accuracy trumps everything else, so you have to test to know what WORKS best for you. I've found that 80-90 gr bullets are working very well out to those distances for me. Much beyond there and bc of the heavier bullets starts to overcome the difference in the raw accuracy edge of the lighter ones. Of course there will be exceptions and people that will claim the 105 class bullets in an 8 twist are great..but they either don't show up or don't shoot well enough to be competitive at short range when they do actually show up at a match. So, this is what I have found to be the best range of bullet weights for ME in a 6 Grendel and 6BR! YMMV.
Sorry about the formatting when I paste it here.


68s

Range Elevation Elevation Elevation Windage Windage Windage Time Energy Vel[x+y]
(yd) (in) (MOA) (MIL) (in) (MOA) (MIL) (s) (ft.lbf) (ft/s)
0 -1.50 0.00 0.00 0.03 0.00 0.00 0.00 1797 3450
100 -0.01 0.01 0.00 1.00 0.95 0.28 0.09 1409 3055
200 -2.26 1.08 0.31 4.10 1.96 0.57 0.20 1096 2694
300 -9.34 2.97 0.86 9.74 3.10 0.90 0.32 842 2361
400 -22.71 5.42 1.58 18.43 4.40 1.28 0.45 636 2052
500 -44.40 8.48 2.47 30.87 5.89 1.71 0.61 472 1768
600 -77.31 12.30 3.58 47.85 7.62 2.22 0.79 347 1515


80's
Range Elevation Elevation Elevation Windage Windage Windage Time Energy Vel[x+y]
(yd) (in) (MOA) (MIL) (in) (MOA) (MIL) (s) (ft.lbf) (ft/s)
0 -1.50 0.00 0.00 0.03 0.00 0.00 0.00 1935 3300
100 0.00 0.00 0.00 0.89 0.85 0.25 0.10 1571 2973
200 -2.45 1.17 0.34 3.63 1.73 0.50 0.20 1267 2671
300 -9.80 3.12 0.91 8.55 2.72 0.79 0.32 1012 2387
400 -23.29 5.56 1.62 16.02 3.82 1.11 0.45 799 2121
500 -44.55 8.51 2.47 26.52 5.06 1.47 0.61 623 1873
600 -75.78 12.06 3.51 40.62 6.46 1.88 0.78 481 1645





90gr bt
Range Elevation Elevation Elevation Windage Windage Windage Time Energy Vel[x+y]
(yd) (in) (MOA) (MIL) (in) (MOA) (MIL) (s) (ft.lbf) (ft/s)
0 -1.50 0.00 0.00 0.03 0.00 0.00 0.00 1983 3150
100 -0.01 0.01 0.00 0.66 0.63 0.18 0.10 1712 2927
200 -2.59 1.23 0.36 2.64 1.26 0.37 0.21 1471 2713
300 -9.90 3.15 0.92 6.13 1.95 0.57 0.32 1256 2507
400 -22.76 5.43 1.58 11.31 2.70 0.78 0.45 1067 2310
500 -42.16 8.05 2.34 18.39 3.51 1.02 0.58 900 2122
600 -69.30 11.03 3.21 27.65 4.40 1.28 0.73 754 1942





105vld
Range Elevation Elevation Elevation Windage Windage Windage Time Energy Vel[x+y]
(yd) (in) (MOA) (MIL) (in) (MOA) (MIL) (s) (ft.lbf) (ft/s)
0 -1.50 0.00 0.00 0.03 0.00 0.00 0.00 2029 2950
100 0.00 0.00 0.00 0.58 0.55 0.16 0.11 1801 2779
200 -3.02 1.44 0.42 2.27 1.08 0.32 0.22 1592 2613
300 -11.14 3.54 1.03 5.23 1.66 0.48 0.33 1403 2453
400 -25.05 5.98 1.74 9.58 2.29 0.66 0.46 1231 2298
500 -45.55 8.70 2.53 15.44 2.95 0.86 0.60 1076 2148
600 -73.60 11.71 3.41 22.99 3.66 1.06 0.74 937 2004

That is excellent info, thanks for sharing. What mph was the theoretical wind?

 

[DennisH]

8 twist pushing 107 SMK's (pointed) remains my favorite.

I have the 6br, BRX, Dasher, & the 6.0x47L. All love the 107's.

The BRX & Dasher are my "favorite" and most accurate rifles.

JMO

 

[rkittine]

+ 1 For the Pointed Sierra 107s and an 8 twist. I shot them well in a 6x47 at 1,000 yards. (Andy's gun last year at Williamsport.)

Bob

 

[gunsandgunsmithing]

That is excellent info, thanks for sharing. What mph was the theoretical wind?

10mph from 3 or 9 o clock