Vertical Stringing

[juanvaldez]

Was doing some load testing with my Shilen bbl'd LRPV. Shot the groups below consequetively with no cool down between strings. The top group should actually be rotated 90 degrees. Any suggestions?


Caliber- 6MMBR
Action- Savage LRPV
Barrel- Shilen 1-12 30"
Trigger- Savage Accutrigger
Stock- Savage HS Precision
Optics- Muller 8x32 SF
Rings/Base- Burris Sig Z
Accessories-
Hand loading recipe- 70 gr SMK over 34 grains Varget
Dies and other reloading accessories- Forster

 

[Mystic Precision]

Please visit my website and look in the Rifle tech section. I have a few articles on load tuning that will be helpful. Paying attention to all the small details will matter when trying to keep groups in the 2's.

By adjusting your load in very small powder increments, you will be able to dial the vertical out. That is where I would start.

Also, make sure that aiming error is not at play - mirage, wind and size of reticle can affect how you aim.

Is the action bedded in the stock properly? That can help.

Did you use that rifle rest? That might be moving enough to cause vertical.

Looks like the loads are shooting quite well so you are well on your way to dialing in this barrel.

A bit more tuning and keeping an eye on conditions and rests may yield the smaller groups you want.

You need to ensure your scale is weighing to the same tenth. If the scale varies more, it can drive you nuts trying to tune a small case.

Let me know...

Jerry

 

[juanvaldez]

It is bedded. It was shot with a firecontrol front a protecktor rear bag. My scale is dead on against an rcbs balance...using a loadmaster. I did have quite a bit of mirage as the bbl heated up. I will try again and wait longer between strings. Any direction on powder increments?? I am at the published max load.

All in all I still very pleased. The bbl does not give fliers...very consistent and very clean. Definately can't go wrong with those Shilen prefits. I am guessing it is the nut behind the wheel more then anything. I am quite please withe mueller scope as well. As I and others have said...the glass is unbelievable for such a low cost. Once my 10-50x60 sightron is maybe I can do better...

 

[Mystic Precision]

the goal is to reduce the variables then repeat to make sure that one occurance is the trend, not a one of.

When tuning small cases, I would go in 0.1gr increments on either side of a node and look for where the groups goes horizontal. The group size will not change but the height of the group will flatten.

It is so important that the error in a scale is UNDER 0.1gr. Not just what it reads but what it actually weighs.

Wind flags will help. so will shooting on a cloudy day.

give it a bit more tuning and I am sure you will find a good combo. maybe another bullet will be more to the barrels liking.

But as I said, you are right in the 2's so you are already doing very well.

how far did you test?

Jerry

 

[CyaN1de]

Seating depth can also affect stringing. Try moving in/out in .005 increments with current powder charge and see if that helps.

My load development always starts with bullets just at/off the lands by .001 or .002 until I find the powder load that it likes, then I tune the load with the seating depth.

Here is a good article http://www.6mmbr.com/verticaltips.html