groups of different size ?

[David Christian]

How do you get away from varried neck tension ?

@rebs, do you use a chrono? Let’s separate your brass prep/loading process from your rifle handling and flag reading skills.

Can you shoot your 5 shot groups over a reliable chrono and compare ES/SD for each 5 shot group as well as all groups together? If you are not averaging an ES close to 20 or less, I think we can lean towards brass prep as a culprit. If you are seeing good numbers I would think you need to examine your bag set up or flag skills.

Have you tried testing at 100 yards to remove some of the environmental variables?

DC

 

[jimmymac]

Bart, Boyd and Randy got you covered. A lot of experience spoke in this thread.

 

[rebs]

BTW, what twist rate is your T3 ?
Projectile weight ?

Thank you guys for all the replies, it is a 1/8 twist and I am shooting 69 gr SMK's. Also I am shooting an F class black target and find it difficult to sight. where do you guys hold your aim point on F class targets ? I am thinking about trying a 6 o'clock hold to help with the fine cross hairs on the black target.

 

[David Christian]

Thank you guys for all the replies, it is a 1/8 twist and I am shooting 69 gr SMK's. Also I am shooting an F class black target and find it difficult to sight. where do you guys hold your aim point on F class targets ? I am thinking about trying a 6 o'clock hold to help with the fine cross hairs on the black target.

@rebs put a white sticker over the bullseye.

 

[dstoenner]

Nobody has mentioned sorting the ammo by concentricity. I load in groups of either 50 or 100. I then sort my ammo. Even Lapua will have the occasional, oh crap, 3 to 5 thousands out. I use those as foulers and sighters to get started. I only uses 1's and 2's for record. The issue here is to get a potential flyer out so you can really concentrate on your shooting and see where you might improve.

David

 

[JFrank]

Might be that 3-5 thousand variables on concentric rounds haven’t proven detrimental to accuracy’ but a bit of 2:00 wind has.
J

 

[Webster]

Normal shooter variability is a lot of it. But I would segregate those with obvious differences in seating force to compare on the target for impact.

Always wondered if seating force was related to how the bullet is aligned with the case neck, even with a quality so called straight line seater.

 

[CharlieNC]

Always wondered if seating force was related to how the bullet is aligned with the case neck, even with a quality so called straight line seater.

Webster I never investigated the potential mechanism(s), but I experienced variable seating force causing significant differences in seating depth. That is when I started annealing, which resolved the issue.

 

[rebs]

Nobody has mentioned sorting the ammo by concentricity. I load in groups of either 50 or 100. I then sort my ammo. Even Lapua will have the occasional, oh crap, 3 to 5 thousands out. I use those as foulers and sighters to get started. I only uses 1's and 2's for record. The issue here is to get a potential flyer out so you can really concentrate on your shooting and see where you might improve.

David

How do I check concentricity ?

 

[BoydAllen]

Google concentricity gauge.

 

[Bc'z]

How do I check concentricity ?

Google concentricity gauge.

There was a hornady in classifieds last week start shopping there.

 

[BoydAllen]

Personally, I would not choose one that uses the rim for the rear case support.

 

[dstoenner]

How do I check concentricity ?

Sinclair makes one that I use. It is fast and easy. Runs about $100 with mechanical dial indicator. Every now and then one shows up in the classified section here.

David

 

[Sandstorm]

Sinclair is what I use....but dont need it much anymore.

 

[JFrank]

^^^Exactly
We’ve had this conversation’
You’ll use it once or twice than it collects dust on the shelf.
J

 

[dstoenner]

^^^Exactly
We’ve had this conversation’
You’ll use it once or twice than it collects dust on the shelf.
J

I use mine all the time. It is just part of my reloading procedure. Why take chances with shooting a 5 runout in a group of 1’s or 2’s runout and wonder what happened? If I know I shot all 1 runout and one shot is not in the group I immediately start trying to figure out what i did wrong in my technique.

David

 

[JFrank]

I use mine all the time. It is just part of my reloading procedure. Why take chances with shooting a 5 runout in a group of 1’s or 2’s runout and wonder what happened? If I know I shot all 1 runout and one shot is not in the group I immediately start trying to figure out what i did wrong in my technique.

David

I’ve shot .005 next to .001 runout with absolutely no difference in point of impact.
Runout is way down the list for my routine.
I’m not trying to be a jerk or put anybody down for checking these are just my findings.
Wind and mirage has a far greater effect on my results at 600 yards.
Jim

 

[BartsBullets]

I’ve shot .005 next to .001 runout with absolutely no difference in point of impact.
Runout is way down the list for my routine.
I’m not trying to be a jerk or put anybody down for checking these are just my findings.
Wind and mirage has a far greater effect on my results at 600 yards.
Jim

Yep! Yep! Yep! Exactly right!!!

Bart

 

[XTR]

I weigh my cases and bullets and hand measure every powder charge. I neck size the brassafer complete cleaning including primer pockets. When I seat the bullets I can feel a difference, sme seat firmer than some others. Now when I shoot them I get a five shot group that can be covered with a quarter at 200 yards but the next group will be bigger and the next bigger then I shoot one that is under a quarter again. Like no consistency or very little. Can this be attributed to neck tension since some bullets seat easier than others ? If thats the case how can I get more consistency ? This is 223 being shot from a Tikka T3x varmint.
It could always be the case that it is just my shooting.

How many shots in the groups?

Reality is that statistically 5 shot groups have a very low confidence value. What it sounds like you are describing is a standard distribution for about a ¾ to 1 MOA rifle.

It is exactly what happens to F class shooters who have what they think is a 1/3 MOA load then they get in a match and drop 3 or 4 points to vertical in a 20 shot match, because what they really have is a ¾+ MOA load. It will shoot three ¼ to ½ MOA groups in a row, with the occasional flyer that they blame on something. Those flyers aren't anomalies, they are part of the distribution. They will come off of the line and say that their load isn't working for some reason, truth is, it was never working.

Take a look at this, it's pretty statistics heavy, but if you scroll down and look at the 3 shot group example, and the 1, 2, 3 sigma discussion below it, they are pretty good.

http://ballistipedia.com/index.php?...al_Shots_Imply_Rayleigh_Distributed_Distances

 

[JFrank]

I weigh my cases and bullets and hand measure every powder charge. I neck size the brassafer complete cleaning including primer pockets. When I seat the bullets I can feel a difference, sme seat firmer than some others. Now when I shoot them I get a five shot group that can be covered with a quarter at 200 yards but the next group will be bigger and the next bigger then I shoot one that is under a quarter again. Like no consistency or very little. Can this be attributed to neck tension since some bullets seat easier than others ? If thats the case how can I get more consistency ? This is 223 being shot from a Tikka T3x varmint.
It could always be the case that it is just my shooting.

Do sort your Bullets BBTO?