Group stringing vertically

[Crockett]

I've bought a new Kimber rifle and am having trouble with accuracy. Generally I was getting 3 to 4 inch groups -- 3 shot. I lightened the trigger to 2.5 lbs and free floated the forend.

Now it's stringing vertically which,correct me if I'm wrong) means irregular pressure on the side somewhere. Horizontally it's printing about 3/4 inch or less -- vertically it's about 2 inches now. The action seems to be bedded tightly,also pillar bedded)as does the first inch,or so) of barrel.

I figure I could coat the action and first part of the barrel with some kind of coloring agent,like magic marker), put it back into the stock, tighten the screws -- then take it out and see where it's binding.

My questions --
1 - What coloring agent should I use?
2 - Does anybody have any other ideas of a better way to find the problem?

Thanks,
Crockett

 

[tenring]

I have a Kimber 84 sporter .308; it has been returned to the factory 3 times and twice to local gunsmiths for numerous problems. I will never buy one again. Hope your luck with Kimber is better than mine.

What model and caliber is yours? Are you using factory or handloaded ammo? What scope is on it? Have you checked scope mounts and rings? There are many causes for vertical, i.e. badly fouled barrel, poor bedding, bullets not concentric, etc., etc. Are the pillars bedded at 90 degrees? Mine were not until Kimber replaced the stock,that was a minor problem). Go to a NAPA store, buy a small tube of Prussian blue. Dissasemble firearm. Place a thin coat of blue on metal areas you want to check; assemble firearm. When you take it apart, blue stains will show you high areas of wood in contact with metal. Remove those areas. Use denatured alcohol to remove blue stain from metal parts. But before you remove any wood, I suggest you check the areas above. Good luck.

 

[steveyrock]

here is a good read on vertical

http://www.6mmbr.com/verticaltips.html

 

[Crockett]

What model and caliber is yours? Are you using factory or handloaded ammo? What scope is on it? Have you checked scope mounts and rings? There are many causes for vertical, i.e. badly fouled barrel, poor bedding, bullets not concentric, etc., etc. Are the pillars bedded at 90 degrees? Mine were not until Kimber replaced the stock,that was a minor problem). Go to a NAPA store, buy a small tube of Prussian blue.

Mine is a 270WSM Montana. I've lapped the scope rings and tried two different scopes -- a Leupold 2.5x8 and an older 3x9 Redfield. I've used 150 gr. Winchester factory loads -- handloads in 130 gr Hornady, 130 gr Barnes Triple Shock, 130 gr Nosler Ballistic Tips and 145 gr Hornady SPBT -- all with various loads of RL19. I've also used new unfired WW cases as well as neck sized once fired cases.

The groups have gotten better since I used the neck sized cases but only to the extent that it's more obvious that my groups are stringing.

I also use a very heavy front benchrest,made I believe by Eagle) and a Protector rear bag. I, personally am capable of shooting .5 inch groups -- with other rifles.

I am religious about barrel cleaning but even as new, the rifle wouldn't give good groups.

I'll take a look at my pillars tomorrow and also go and pick up some Prussian blue.

Thanks for the advice -- I'll check in after my next range session.

Crockett