Reloading: Please help me interpret a target.

[skeeter 20i]

I am trying another powder out of my Tikka T3 lite  a 139SST.   Anyway this 3 shot string showed almost zero vertical change @100yds now correct me if I'm wrong here but this is a good thing yes?  I can attribute the horizontal to varying L to R wind but the vertical staying consistent tells me I want to retest that string with a 5 shot group to prove the load.  I've just never seen them line up like that horizontally so I was curious what you all have to say. 

Sorry if it's a NOOB question but I'm still learning.

[DRobnsn]

How much wind?

[bobcat]

That's quite a spread in your point of impact. I wouldn't expect that the wind was the cause of that at only 100 yards. But maybe it was, just depends on what the wind was doing. But if it were windy enough to move your bullets around that much, I wouldn't have been shooting for groups.

[Kittman]

Things that come to my mind- Is the barrel warming up getting hot and contacting the stock somewhere?  All free-floated?  I would re-check scope fasteners for security also.   

[jackelope]

A friend told me that left to right stringing is trigger torque.

[skeeter 20i]

The other groups were acting the way I would expect as for rounds coming together and then spreading out.  The 1/2 gr prior was 2 out of 3 touching but I pulled one flyer and  it will probably be the "dial it in" load but the horizontal spread just had me curious since I'd never seen one do that. 

I was wondering if this was lending itself to the "ladder tests" type scenario where you look for very little vertical change.  I thought it might be wind and or the trigger man or a combination of both, I just ran the numbers and I should have only been getting ±.25moa/5mph of wind at that distance and I would guess we were 10-15mph of wind. 

Perhaps I should just chalk it up to  I was planning to re-shoot the string @5 shots without changing anything to see.  It just had me scratching my head. 

I need to get started building the loads for the .243 this 7mm target shooting for groups every weekend is going to wear my brass out. 

[CaNINE]

I'm no expert but here are some ideas...

One thing I've learned from reloading and load development is that it's really difficult to diagnose something based off of one data point.  The other thing I've learned is that developing a good load take A LOT of time and adjustment in brass prep, seating depth, component manipulation, etc, etc, etc.  I had no idea how complicated precision loading was and still learn something new everytime I go to the range.  Sometimes I get lucky but usually developing THE load takes weeks or months. 

Based upon my limited expertise here are some thoughts...

1.  Your consistent vertical tells me your loads probably have very consistent velocity.  This is good.
2.  The variation in horizontal is probably barrel timing.  Meaning, that this particular velocity is not quite in the sweet spot to product the lowest barrel harmonics. 
3.  I would go up or down in 0.5 grain increments to see if the group improves.
4.  Then start adjusting seating depth to fine tune the amount of jump to best match your barrel timing.
5.  How many brass sizing cycles do you run before you anneal?  Consistent neck tension is extremely important to repeatable results.  Ive proved to myself that it's so important that I'm now annealing every other brass cycle and may just do it every time.  It's that important.

[high country]

First off,  3 shot groups are tough to diagnose unless you have several.  I'd first inspect my scope and run around the box groups to ensure its tracking properly. If that is a pass, I'd have someone else shoot it and pay close attention to form. The way you mount the rifle can have effects. If this has,not revealed anything I'd play with my seating depth about. 025" each way and repeat.

[Bill W]

I would check out the stability of your rest for one thing and how your rifle fits in it.  There's other things to look at after that.

[Reidus]

1 three shot group is not enough to pull any serious conclusions from. If you can duplicate this, then you may be onto something.

[kisfish]

tagging along

[CAMPMEAT]

Lead Sled.....

[HawkCreek]

If the load previous the one pictured was touching I'd load up a few batches of both and test them both out carefully. As long as you know the barrel isn't making contact somewhere stringing like that can be caused by improper trigger finger technique or improper alignment i.e. "muscling" the rifle (depending on the shooting position can be more or less).

[2labs]

I think you might have a load your rifle likes! That horizontal string is almost perfecto!
 

[Blacklab]

A friend told me that left to right stringing is trigger torque.

 

Very well could be if your right handed 

First I'd check scope
second trigger pull
third load development/seating depth

Just like elbows everybody has a couple..............