Tuning and Bullet holes

[Tim Singleton]

What do you notice from the bullet holes in these groups?
This is something turning a tuner can’t help

 

[Cfshooter]

What do you notice from these groups?
This is something turning a tuner can’t help

POI drops as barrel heats up

 

[Tim Singleton]

POI drops as barrel heats up

nope
Ill revise the post. the title is about the bullet holes not the groups

 

[Cfshooter]

no clue, looks like target wasn't on a firm backer, or this paper, but not sure how a tuner or anything else would help clean up the holes any.

 

[L.Sherm]

The lower left ones are not tearing the paper like the top ones.
I heard Jack Neary talk about this on Eric's podcast once.
I would say lower left were in better tune

 

[Tim Singleton]

no clue, looks like target wasn't on a firm backer, or this paper, but not sure how a tuner or anything else would help clean up the holes any.

Look at the bullet holes on the bottom row compared to all the rest

 

[jimmymac]

Bullets have yaw.

 

[jxb]

Bullets have yaw.

This is what I noticed, they all print hard lower right and basically nothing upper left. Is that a twist issue or a leaving the barrel issue?

 

[Tim Singleton]

The gun still isnt right but closer with the bottom row took a powder change for it

The lower left ones are not tearing the paper like the top ones.
I heard Jack Neary talk about this on Eric's podcast once.
I would say lower left were in better tune

Yep, the bottom row is getting better
All of the others were 5 shot groups with several different powder weights and seating depths.
It took a powder change for it to start shooting like a benchrest rifle

 

[BoydAllen]

Years ago, I started a one shot per load pressure and node investigation a lot lower than I had intended (did the mental math for powder measure clicks wrong). The first three shots' (.3 gr. intervals) holes looked like they were .22 caliber. I did not investigate further because, at the time I was not aware of anyone shooting slow velocities, and doing well. If you think that we should tune for the cleanest holes then the bottom row is the best.

 

[Tim Singleton]

Years ago, I started a one shot per load pressure and node investigation a lot lower than I had intended (did the mental math for powder measure clicks wrong). The first three shots' (.3 gr. intervals) holes looked like they were .22 caliber. I did not investigate further because, at the time I was not aware of anyone shooting slow velocities, and doing well. If you think that we should tune for the cleanest holes then the bottom row is the best.

they sure measure smaller

 

[rwj]

Bullets have yaw.

Powder charge too high or too low?

 

[Mulligan]

The gun still isnt right but closer with the bottom row took a powder change for it

Yep, the bottom row is getting better
All of the others were 5 shot groups with several different powder weights and seating depths.
It took a powder change for it to start shooting like a benchrest rifle

Out here in the arid country, I have seen this when switching from 133 to LT, and the other way around.
Somewhere on this forum I posted a pick like yours asking about the smaller holes and uniform black around them.
I still do not fully understand it.

CW

 

[jimmymac]

Powder charge too high or too low?

I have no idea but I’d be playing with seating depth and powder charge simultaneously until the yaw goes away and turns into a nice uniform burned up round hole.

I’m specifically talking about the bottom row of the target.

 

[Tim Singleton]

I have no idea but I’d be playing with seating depth and powder charge simultaneously until the yaw goes away and turns into a nice uniform burned up round hole.

I’m specifically talking about the bottom row of the target.

that bottom row was 4 different charge weights getting hotter right to left

 

[Tim Singleton]

Out here in the arid country, I have seen this when switching from 133 to LT, and the other way around.
Somewhere on this forum I posted a pick like yours asking about the smaller holes and uniform black around them.
I still do not fully understand it.

CW

YES
I couldn't get 133 to do anything good. I switched to Lt32 and the bottom row began to look like something

Hotter than usual for our area today

 

[Tim Singleton]

I have no idea but I’d be playing with seating depth and powder charge simultaneously until the yaw goes away and turns into a nice uniform burned up round hole.

I’m specifically talking about the bottom row of the target.

the seating depth is still off just a scosh but it did finally start to look like something on the bottom left at 28.9 LT32

 

[jimmymac]

the seating depth is still off just a scosh but it did finally start to look like something on the bottom left at 28.9 LT32

Lower left is clearly the best. Almost no vertical.

 

[Bill Norris]

YES
I couldn't get 133 to do anything good. I switched to Lt32 and the bottom row began to look like something

Hotter than usual for our area today

N-133 can be a dog to work with at times. Really seems sensitive.

 

[bugman]

Tuning per the appearance and relative size of holes requires a lot of attention to a good backer material.