1 lighter bullet in a 6br/?

[JEFFPPC]

Year's ago I did very well with a pair of 6brs in 10 twist. One like 80 Bergers the other 88. The 90 gr version never was quite as accurate as the 80 or 88 in those barrels. I never considered a slight drift advantage on paper a factor. You learn to equate your rifle with your flags. If one drifts 1.3 and the other 1.9 I don't think many could ever tell the difference even if they think they can. Now if you don't do flags and poke and hope I suppose on a given day it might change a point or two. I will take what groups best and trust my flags. Your gun will tell you what it likes, trust your target.

 

[jackieschmidt]

Don't overlook Barts 80gr Dominator

^^^^^^^[

 

[Dolomite]

Is it possible to shoot small groups with an 80 gr bullet out of a 1:8 twist jumping the bullet over .050+?

 

[foxguy]

I'm jumping my 80 Gr bullets .030 thousand's. That's the distance off the lands that the rifle liked, I tried out to 0.045, I didn't try -0.050 because the -0.030 was shooting them into 1 slightly enlarged hole at 100 yds. I was originally shooting them in the land's appx 0.010, they shot pretty well there but not as good as off the lands.

 

[Trigger-Jerker]

I'm jumping my 80 Gr bullets .030 thousand's. That's the distance off the lands that the rifle liked, I tried out to 0.045, I didn't try -0.050 because the -0.030 was shooting them into 1 slightly enlarged hole at 100 yds. I was originally shooting them in the land's appx 0.010, they shot pretty well there but not as good as off the

Which 80 gr bullet was that?

 

[NZ_Fclass]

I like the 95 MK for the 300 metre match.

 

[foxguy]

Which 80 gr bullet was that?

Bart's Dominator.

 

[Dolomite]

I'm jumping my 80 Gr bullets .030 thousand's. That's the distance off the lands that the rifle liked, I tried out to 0.045, I didn't try -0.050 because the -0.030 was shooting them into 1 slightly enlarged hole at 100 yds. I was originally shooting them in the land's appx 0.010, they shot pretty well there but not as good as off the lands.

I have a .120 free bore and the bullet is no where near touch, in fact it falls out of the case when trying to reach the lands. Any suggestions where to start?

 

[foxguy]

My Free Bore is .105 and I have .276 of bullet in the case.
The bullets length is .942.,
The Boat Tail length on the bullet is .100.
My Laupa brass case has .176 of grip on the bullet.
My Case trim length is 1.555

My Cartridge Overall length is 2.240 @ .030 off the lands

Your free bore =.120 but you say the bullet falls out of the case when trying to reach the lands.
My thought is If your free bore is .120, the bullet should not be falling out of the case trying to reach the lands?? My math might be off, but with .120 of free bore I'm thinking you should still have appx .150 of bullet grip in the case ???

Given all of this, my best guess is to start at 2.275 COAL and with a medium load, shoot 3 shot grps.
Vary your seating Depth in .005 increments testing for a seating depth that your barrel likes (seating deeper into the case - off the Lands) if after testing 10-12 different seating depths and you are not shooting small groups you may want to consider using a different bullet.

 

[Bc'z]

My Free Bore is .105 and I have .276 of bullet in the case.
The bullets length is .942.,
The Boat Tail length on the bullet is .100.
My Laupa brass case has .176 of grip on the bullet.
My Case trim length is 1.555

My Cartridge Overall length is 2.240 @ .030 off the lands

Your free bore =.120 but you say the bullet falls out of the case when trying to reach the lands.
My thought is If your free bore is .120, the bullet should not be falling out of the case trying to reach the lands?? My math might be off, but with .120 of free bore I'm thinking you should still have appx .150 of bullet grip in the case ???

Given all of this, my best guess is to start at 2.275 COAL and with a medium load, shoot 3 shot grps.
Vary your seating Depth in .005 increments testing for a seating depth that your barrel likes (seating deeper into the case - off the Lands) if after testing 10-12 different seating depths and you are not shooting small groups you may want to consider using a different bullet.

Great information
Care to share some load info?
I'm more curious about powder selection/velocity, brass and primer used

 

[foxguy]

Great information
Care to share some load info?
I'm more curious about powder selection/velocity, brass and primer used

80 Gr Barts -.030 OTL's, IMR 8208, 29.8 grs, Velocity ??? ,Laupa Brass, CCI 450 Pri

90Gr Berger BT Target +.009 ITL's, Varget, 29.6, Velocity ???, Laupa Brass, Fed 205m Pri

Bc'z

Both rifles are chambered for 105 gr class bullet.
I'm shooting the 80's in my Factory Savage F-Class 6MM BR rifle.
The 90's in my Custom 6MM BRA Kreiger barrel Fire Forming the Brass.

Amazing how well the 90's shoot fire forming. My initial test @ 100 yds ,2 shots into the same hole.
This was with the bullets .009 ITL's. Since the initial load / seating test. I have shot 1 "UBR 243 Target" at 100 yds. shooting in 6-10 MPH winds. I was able to shoot a Score of 60 w/4X's. This is just a Local club shooting centerfires for some bragging rights.

 

[foxguy]

80 Gr Barts -.030 OTL's, IMR 8208, 29.8 grs, Velocity ??? ,Laupa Brass, CCI 450 Pri

90Gr Berger BT Target +.009 ITL's, Varget, 29.6, Velocity ???, Laupa Brass, Fed 205m Pri

Bc'z

Both rifles are chambered for 105 gr class bullet.
I'm shooting the 80's in my Factory Savage F-Class 6MM BR rifle.
The 90's in my Custom 6MM BRA Kreiger barrel Fire Forming the Brass.

Amazing how well the 90's shoot fire forming. My initial test @ 100 yds ,2 shots into the same hole.
This was with the bullets .009 ITL's. Since the initial load test. I have shot 1 UBR 243 Target at 100 yds. shooting in 6-10 MPH winds. I was able to shoot a Score of 60 w/4X's.

I Suspect with the 90 Gr Berger Target bullets, after fire forming, I will have to increase the Varget powder charge a few tenths of a gr. After fire forming all pieces of the brass, I will move onto testing the load with the newly fireformed brass. I am looking forward to that as it's all a learning process.

 

[Clancy]

I have a .120 free bore and the bullet is no where near touch, in fact it falls out of the case when trying to reach the lands. Any suggestions where to start?

An 80 Dominator, or especially a Berger, is nowhere near falling out of the case with a .120 freebore. Something is off.

 

[Dolomite]

An 80 Dominator, or especially a Berger, is nowhere near falling out of the case with a .120 freebore. Something is off.

I was using that hornady tool with Berger 80 gr FB. Let me try the wheeler method,

 

[foxguy]

I was using that hornady tool with Berger 80 gr FB. Let me try the wheeler method,

According to Berger the 80 GR FB bullet is a tangent ogive design, they say that these bullets are very forgiving and should be seated off the lands. Once you identify the bullets touch point in the chamber, I would suggest that you start at .010 off the lands shooting 3 shot Grps, increasing your seating depth off the lands in .005 thousand increments, .010,.015, .020...... ect testing to .050 off the lands. I think your testing will identify a small group that you can work with.

 

[Dolomite]

According to Berger the 80 GR FB bullet is a tangent ogive design, they say that these bullets are very forgiving and should be seated off the lands. Once you identify the bullets touch point in the chamber, I would suggest that you start at .010 off the lands shooting 3 shot Grps, increasing your seating depth off the lands in .005 thousand increments, .010,.015, .020...... ect testing to .050 off the lands. I think your testing will identify a small group that you can work with.

Great thanks for the advice I’ll give it try. Are the FB based bullets better for accuracy at 100 yards?

Update using the wheeler method I found the lands. Will give it a go in the next few weeks.

I’m not sure why I even bother with the horandy tool. Too much inconsistencies.

 

[Dolomite]

I Suspect with the 90 Gr Berger Target bullets, after fire forming, I will have to increase the Varget powder charge a few tenths of a gr. After fire forming all pieces of the brass, I will move onto testing the load with the newly fireformed brass. I am looking forward to that as it's all a learning process.

Let’s us know how it turns out. Maybe I need to try them 90 gr bullets.

 

[foxguy]

Great thanks for the advice I’ll give it try. Are the FB based bullets better for accuracy at 100 yards?

With the 80 Gr Bergers I was able to shoot several 1/2 in groups at 200 yards.
Once you find your rifles preferred seating depth, they should work well.

 

[SteveOak]

If you run JBM calculator, you can run the lighter bullet faster and at 300yds.
the drift will almost be the same and the drop will be less with a lighter bullet.
Slightly less recoil.

Shhhhh

 

[Bc'z]

80 Gr Barts -.030 OTL's, IMR 8208, 29.8 grs, Velocity ??? ,Laupa Brass, CCI 450 Pri

90Gr Berger BT Target +.009 ITL's, Varget, 29.6, Velocity ???, Laupa Brass, Fed 205m Pri

Bc'z

Both rifles are chambered for 105 gr class bullet.
I'm shooting the 80's in my Factory Savage F-Class 6MM BR rifle.
The 90's in my Custom 6MM BRA Kreiger barrel Fire Forming the Brass.

Amazing how well the 90's shoot fire forming. My initial test @ 100 yds ,2 shots into the same hole.
This was with the bullets .009 ITL's. Since the initial load / seating test. I have shot 1 "UBR 243 Target" at 100 yds. shooting in 6-10 MPH winds. I was able to shoot a Score of 60 w/4X's. This is just a Local club shooting centerfires for some bragging rights.

Just ran 3 powders through GRT.
SWP, N140, IMR4166