vertical stringing?

[Rich Coyle]

Anyone have a solution for vertical stringing? I spent half an hour trying to crop and resize these. Photobucket is not working with me.

 

[Buckskinner]

I wish I could give you an easy fix, but there are so many variables that can cause vertical stringing.

Could be any number of issues with the rifle. Stock flex or poor bedding, trigger, firing pin, unbalance rifle
Could be scope
Could be you loads or primer
Could be you barrel heating
Could be your bag set up
Could be your shooting form

If not stock, I think I would look at primers first, may be inconsistent.

 

[velvetant]

Need lots more info.
Barrel free floated?
ES looks good, assuming 100 yards.
How did you work up load? Ladder test?
New rifle?
Rifle/stock/scope/cartridge?
Heavy rifle, bull barrel, light rifle, pencil barrel?
Shooting off of......Bench/sandbags?
slow fire, barrel cool each shot?

 

[bigedp51]

Many stock factory rifles have up pressure at the fore end tip to help control barrel vibrations.

The older Remington 700 had 3 to 9 pounds of up pressure, and a No.4 Enfield rifle had 2 to 7 pounds of up pressure.

Vertical stringing can be controlled by up pressure at the fore end tip. Military rifles must be tuned to issued ammunition and this was done through bedding forces.

Also many rifles can be tuned by torquing the action screws that changes barrel vibrations.

Savage Action Screw Torque Tuning

http://www.accurateshooter.com/technical-articles/savage-action-screw-torque-tuning/

 

[tokatee]

Make sure all action screws are tight,make sure scope mounts are tight.
What is the rifle?

 

[Rich Coyle]

Thanks for the replies. The rifle is a is used but new to me Weatherby Mark V six lug .270 Win. The load consists of Barnes TTSX 110 grain bullet powered by 63.5 grains of Hunter. According to Barnes a max load is 65.7 grains producing 3,507 feet per second.

I tried four primers today. I stopped at three shots with Federal 215 Magnum because the group was too big. It was also vertical. I didn't try anymore Remington 9 1/2M after the second one failed to fire with two strikes. I had that problem with another rifle.

I will check the screws when I get home.

 

[philipbrousseau]

does it have the thin weatherby contour barrel? has a previous owner floated the barrel by removing pressure pad near the forend tip? watch the steeply angled section of the stock on the rear bag, it might add some vertical but no where near what you are getting. good luck with it

 

[Rich Coyle]

Well, gentlemen, I checked the action screws. Both were not tight. The rear was slightly tight. Lord willin' tomorrow I will try again.

 

[Laelkhunter]

What distance are those groups fired at?

 

[Rich Coyle]

What distance are those groups fired at?

The groups were fired at 100 yards.

I forgot to answer some of the questions. The barrel is floated clear to the recoil lug. The trigger is set a twenty ounces. I've been using that setting on hunting rifles for decades.

The rifle was fired from bags a little in front of the magazine with a rabbit ears type of bag at the rear. The rifle has a brake so I hold it like I would a BB gun. This has worked in the past to get ten shots in .870" at 200 yards with a .223 and ten shots in .800" at 100 yards with my .257SLR firing GSCustom 85HV at 3,919 feet per second. If I can get the vertical to match the horizontal I will be delighted.

 

[Rich Coyle]

Here's a group after tightening the actions screws with a Fat Wrench to 60 inch pounds. I got the number from Weatherby. Interesting shot number one was away from the others.

 

[velvetant]

I would now play with your charge weight .5g until Max to see if they tighten up.
If that doesn't work then I would play with seating depth.
Looks like you are darn close to the perfect load.

 

[Rich Coyle]

I like you idea of adjusting the load and the length. I will try that in a couple days, Lord willin'. Which would you do first?

 

[velvetant]

I usually do the powder charge first working up to max. You should see your groups tighten then slowly open as you find the sweet spot.
I then fine tune with seating septh