Getting there w/Berger 108's

[JMayo]

5 shot groups. I need grid targets so my poa is more precise. 30.6 varget, 108 Berger bt. .10 jammed. (365 =.10 in)
I'm not sure on measuring. 1/2 hole ?
If so then it's smaller than shown.

 

[Dusty Stevens]

You measure outside to outside of the biggest part of the group then subtract .243 to roughly get your group size. Your paper doesnt lend itself to easy measuring, so you really need to measure a single bullet hole to get a standard to go off of. It may be bigger or smaller but i dont think its really necessary for what youre doing as long as you measure each one the same (outside of black ring, halfway in, only hole- whatever you choose just stick with that)

 

[boltfluter]

Nicely done on your part. Some very good shooting! Looks like you got a good lot of bullets as well.

Paul

 

[22DASHER]

Now hopefully you have a shit pile of them...

 

[mikeeg02]

Is that at 200 yards ? If so, I would shoot them all again at 300. All the groups on that paper look respectable. But at the next distance, you'll start to see the trends better. Good shooting.

 

[Dave Way]

View attachment 1073122
5 shot groups. I need grid targets so my poa is more precise. 30.6 varget, 108 Berger bt. .10 jammed. (365 =.10 in)
I'm not sure on measuring. 1/2 hole ?
If so then it's smaller than shown.

You know, I really don’t care if the groups are at 100 yards, they are still great groups. I’m impressed by the way the shape of the groups and the point of impact seems to stay the same for a 1.5 grain spread in powder charges.

My questions would be, what is the cartridge and is that jam depth accurate? “.10 jammed” is 100/1000” jammed where a more normal jam depth may be .010” or 10/1000”. Just curious-Dave.

 

[jamesdmock]

What chambering was used? 6 BRA, 6BR, Dasher, or ?????/

 

[fatelvis]

When measuring my groups, I usually open up the caliper jaws to .243” and then zero them there. Then I measure the furthest outside to outside of the bullet holes. I don’t know if this is the most accurate way, but it’s fast and simple for me.

 

[JFrank]

I just measure c to c
Maybe I'm wrong " wouldn't be the first time . Either way they are real nice groups
J

 

[mikeeg02]

You know, I really don’t care if the groups are at 100 yards, they are still great groups. I’m impressed by the way the shape of the groups and the point of impact seems to stay the same for a 1.5 grain spread in powder charges.

I've noticed the same when developing a load for my 6br improved barrels. The groups can be hard to distinguish close, between groups that look consistent and have consistent poi. It really pays to shoot the good ones out further to see how they trend. It will start to show further out

Also, based on the charges its likely to be a 6br improved. You wouldn't be likely to put 31.5 of varget in a straight br, or in the 30s in a dasher. Just my .02

 

[JMayo]

6brA, 100 yds.
Using a Sharpe dot caused some error in poa I'm sure. So maybe one hole should have been in several. Still I have a couple to retry.
My calipers 1.8360 is zero
Powder varget, 30.0 - 32... shown
1st, 2nd, 3rd trips. I started at kinda known charges & seating. Then expanded into other charges with found seating likes.

The seating is my comparison from what I found to be zero jammed, 1.8360. 5thou exactly is a tough call.
Y'all can do the math. I know what #'s I'm looking for.
Whether it's .005 or .010 in or out, I have to stop and think ! 1.8 then I read/write 345, 350 365 ....

1
2 (i cut off the top row ....Good one there)
3

 

[Dave Way]

6brA, 100 yds.
Using a Sharpe dot caused some error in poa I'm sure. So maybe one hole should have been in several. Still I have a couple to retry.
My calipers 1.8360 is zero
Powder varget, 30.0 - 32... shown
1st, 2nd, 3rd trips. I started at kinda known charges & seating. Then expanded into other charges with found seating likes.



The seating is my comparison from what I found to be zero jammed, 1.8360. 5thou exactly is a tough call.
Y'all can do the math. I know what #'s I'm looking for.
Whether it's .005 or .010 in or out, I have to stop and think ! 1.8 then I read/write 345, 350 365 ....
View attachment 1073210
1View attachment 1073211
2 (i cut off the top row ....Good one there)View attachment 1073212
3

So it appears to have a preference for 365 or .005” jam. I’m no expert and there are many on this site with way more knowledge than me but I would push the .005” loads to 200 yards just as Mikegg02 said. Then tweak the seating depth by .002 in each direction and see where that leads you. Finally after you have nailed down the seating depth tweak that best charge/seating depth combo by testing neck tension. Just my thoughts-Dave.

Sounds like fun to me. Guess I’m bored.

 

[KenOath]

View attachment 1073122
5 shot groups. I need grid targets so my poa is more precise. 30.6 varget, 108 Berger bt. .10 jammed. (365 =.10 in)
I'm not sure on measuring. 1/2 hole ?
If so then it's smaller than shown.

BRA,BR,Dasher? Looking good so far..

 

[JMayo]

BRA,BR,Dasher? Looking good so far..

6mmBrA