6mmbr group size questions?

[delta1]

I am just about ready to start shooting my Savage 12 F class rifle at the 300 yard targets and the 400 yard targets.
My questions are this. What group size should I be shooting for to be reasonably accurate at the 300 and 400 yard ranges? reasonable group sizes at longer ranges would be helpfull also.
There are no F-Class shooters in my area to go to.
Regards

 

[mjohn7]

If you are looking at F-Class, you will want 1 MOA or smaller
F-class target scoring is approx 1 MOA for the 5 ring, 1/2 MOA for V bull

 

[Dark-Angel]

1/2 MOA to be competitive out to a 900 meters, but keep in mind that depends on a lot of things like bullet, wind, etc.

 

[Obtunded]

Delta1, where abouts are you?

SHORT range F-Class is a .4MOA V-Bull, or 35mm at 300M. The 5 ring is double that, or 70mm/.8MOA

How competitive you want to be is dependent upon how well your fellow competitors shoot

Your rifle should be capable of .5MOA or better under good conditions and with a good shooter. Use Lapua brass, Varget, Reloder 15, VV 140/540 are all good powder choices.

I strongly recommend Berger 105 VLD HUNTING bullets, not the VLD match (yes, seriously... long story but the VLD hunting are their older better VLD match bullets) or Sierra 107 SMK's. I suggest avoiding the Lapua 105 Scenar bullets as they are (from the experience of many including me) difficult to make work and have a poor Ballistic Coefficient.

The 6mmbr.com website has great reading on this incredible cartridge.

 

[delta1]

Obtunded:
I am in NW Ontario.
Here is what I have done so far.
Worked from 29.0-30.6 grains of Varget in .2 grn increments. Shot 2 groups of 5 rounds each with each loading. Best groups with 30.0 grains bullet hard into the lands .225 and .210 CTC My vertical was 1.0-1.5 in. I attribute this to gettting used to the grip I need and getting used to the Savage accu trigger set at 6 oz.
I worked bullet seating from .020 off land to hard into lands. By hard I mean a light push to close the bolt and the bolt needed a light tap to remove a loaded round. All groups opened up if not seated hard into the lands by double.
Bullets were VLD berger 105 grn I could not get VLDH at the time i ordered the bullets.
Brass is new Lapua 6mmbr
Primer is the CCI-450
If you think I need to do something else please comment.
I would like to know where I can get some target centres from Vbul to #4 scoring ring if possible for all ranges 100-700 yds.
Regards

 

[Bob Raymond]

The DCRA would be a source for targets and centers. They may not sell to an individual, but worth a try.

 

[Obtunded]

What I do to load develop is used a technique referred to as "Ladder testing" Each gun and cartridge combo is different, and the amount of powder and the seating depth of the bullet you use will have a "sweet spot". The 6BR typcially has two functional nodes. One at high speed (~2875-2950 fps) and one low speed (2775-2825).

Instead of shooting a buch of groups, I use a ladder test target (see here) and shoot at a known seating depth for the bullets I use (I never knew a Berger VLD that did not like 15 thou of jam) ONE shot per powder weight (Which I divide into .1 grain increments by the way 29 - 31 grains) . It is also important to shoot at a distance where the differences show up, such a 200-300M.

Shooting at one single target with a ladder test is unreliable unless you use complicated techniques for coloring your bullets so you can tell which one was which, and I am way too lazy for that. If you use the attached target and use the same point of aim on each individual target, you will see a pattern. If your shots hit in the same spot (relative to your point of aim) on three different targets, it is pretty fair to say you have a node.

Once the node is found for powder, I repeat the test with seating depth, except I shoot 3 shots for each seating depth.

When the ladder test shows results, then take it out and try a 5 or ten shot group.

You can work out a load using the method you describe but you use way more powder and bullets than you need to.

FYI, The ICFRA F-CLass short range target is the only .4/.8MOA target. They increase to .5/1MOA beyond 300M

 

[delta1]

Obtunded:
Thank you for the ladder test information. I can see where it would have saved me some time and components.Do you have a source for the Vbull out to #4 ring for the distances through 700 yds. I have plenty of heavy card to stick the centres to.
Regards Tim

 

[Obtunded]

The best i can suggest is the ICFRA.com website. It has the technical rules for targets on the site. You can create your own with construction paper, a thumbtack a pencil and some string.

 

[6mm Shooter]

When ladder testing I shoot all the shots at the same target at 300 yards and I keep the same type of target beside me at the bench. After each shot I mark it on the target at the bench and that way I have a reference when I look at the real target. Beats driving out to the target every shot.