Accuracy Problem

[Caver]

My rifle will place the first 10 shots under 1 MOA at 100 yds. It will start to open up with the next 5 rounds to about 2" stringing vertical. Then from the 15th - 20th shot it will walk up and off the target, more than 10" from point of aim. The rifle was custom built on a Remington action and the scope is a Leupold VX111 8.5-25x50. I thought it must be the scope and it is back at Leupold for the third time. I talked with them and they said they repaired it each time. I installed a set of Burris 1" Signature rings with a Bushnell Scope today and found that it is doing the same thing. This makes me wonder about Leupold. What should I look at next that might be the source of this problem?
a Barrel is Free Floated - Action is Blueprinted.
b 5 min or more between shots,barrel was never more than warm)
c Returning rifle to gunsmith is not a option.
d My very first custom rifle, Life's Great.
On the upside, there is a lot of happy Prairie Dogs out there.

 

[dreever]

When I have a problem that I can't figure out I start from the ground up. I slowly remove the scope, rings, bases, remove the action from the stock and begin by looking at everything with the aid of a magnifier. Check the crown, one little nick is all it takes. While looking thru the magnifier run a q-tip over the crown. It should be razor edge sharp. Is the barrel on tight?Examine the stock and bedding put it back together checking for barrel float. TORQUE EVERYTHING WITH A TORQUE WRENCH!
Mount the scope bases and rings the same way. Again, TORQUE EVERYTHING! Same goes for the ring cap screws. Leave no stone, no matter how insignificant unturned. There isn't anything insignificant in this game. Now try a proven load, or premium factory match ammo just after sunup when the wind and mirage are nil.
It could be something so simple so look at everything carefully.
Have a buddy or two shoot it also, that eliminates the human element just in case it's you. Shoot slowly, avoid heat, clean well, by approved methods.
Don't get frustrated, or give up. Take a systematic approach to find the problem. Honestly this isn't rocket science, but if you fail to find the problem then pay a professional to have a go at it.

 

[tightneck]

From your post it sure sounds like you have a big problem with your Loopy. Its been back to them 3 times and they had to fix it every time? Sounds to me like they aint fixin anything.

 

[Forum Boss]

Who made the barrel, and what is the profile?

What is the caliber?

Check the crown for flaws.

What is your shooting set-up,front rest, rear bag?)

Why is a trip to the gunsmith not an option?

 

[Rustystud]

Before you take anything apart.

1. Check the barrel for cooper fouling. Is it a new barrel? Is it a factory barrel or aftermarket barrel? It may need to be lapped.

2 Check for barrel contact with stock. If you don't have at least .30 clearance you may have contact after barrel warms up.

3. Are your bullets measured off OAL. or ogive. Always measure off ogive, bullets are not all the same length. Where they engage the rifling will be different.

If it is your scope or crown the bullets will most likely not be in a verticle displacement they will be irratic an/or scattered.

You can do a simple scope tracking test yourself.

Select a intended point of impact that can be repeated. Shoot one bullet. Adust your scope up scope up 4 inches. Shoot at the same point first aimed at. Adjust your scope over to the right 4 inches. Shoot at the exact same first point that you shot at. Adjust your scope down 4 inches. Shoot at original point. Now adjust your scope back to the left 4 inches.
Again shoot at the first point aimed at. You should have shot a 4 X 4 box. Now adjust your scope up 4 inches shoot at the original point of aim. Now you should have a box with the 5th bullet hole back in the first bullet hole. This will test your scope for tracking since I will bet you don't have a columator.

This test can rule out a lot of other problems as well.

4. Did your gunsmith lapp the lugs? Are you getting 100%bilateral engagement with at least 60% bearing surface contact.
This can be easily tested. Clean all the grease of the lug bearing surfaces with a degreaser. Tahke a permanent marker and color up the bearing surface on the bolt. Close the bolt in the action putting some backward pressure on the bolt. LIft and clost it about 20 times. remove the bolt and check the marking you made on the bolt lugs. Where there is bearing contact the marker will be rubbed off. If your lugs do not have bilateral contact the bolt will heat up as your gun is shot. The metal expands and your unequal bolt lug contact will put presure against your case head unevenly.

I suggest you do test independently to rule out each type of problem. If not you may create more problems as you go along.
Rustystud

 

[Spotcheck_Billy]

You say that your accuracy is OK for the first ten shots, but you never get the barrel hot. After the first ten shots your accuracy starts going away, and seems to get worse the more you shoot.

What do you do to get the original accuracy to return for the next ten shot string? Do you clean the barrel,at home or in the field) and get your accuracy back for the next ten shots only to have it go away again?

If that's the case it sounds to me like your barrel is getting fouled after those first ten shots. Possibly a rough bore. Do you have a custom barrel? Call the barrelmaker. Factory barrel? Some are notoriously rough. Lapping may help, but keep in mind that as you lap the bore you remove metal, so be careful.

If my theory is correct, first try cleaning after those first ten rounds. If the problem diminishes after cleaning you've probably got your answer.

HTH,
Alan

 

[Preacher]

It really sounds like a cleaning probem to me also.
Do like spotcheck mentioned and clean it good again after those 10 good shots.

Burrs on a crown dont allow 10 good shots......

A loose scope dont allow 10 good shots......

A bad scope won't allow 10 good shots either.....

 

[Caver]

I should explain further as to my situation. I had a rifle built by Mike Wilkerson of Indian Arms. Indian Arms is out of business and Mike has disappeared. Phone disconnected. The rifle built on a Rem Action, Krieger Barrel with 1-10 twist, 6MMBR, Shehane 40x stock, Jewel BR trigger,Action blueprinted, Bolt sleeved, pillar bedded, Weaver steel bases with 30mm rings lapped true. There is a real good possibility that I sent a perfectly good scope back to Leupold 3 times to have torn apart and rebuilt. My first three attempts at developing a load was all very similar. The first 10-15 rounds OK but then the next 5 and the point of impact moves off the target always stringing Vertical. Seems to me that a barrel would not foul that bad after 15 rounds to move more than 10 inches in the next 5 shots. But what I have done up to now is ship the scope back to Leupold, clean the rife, wait for scope to return and try again. This is my first custom rifle, it couldn't be the gun:nono:. I might add that there is very little copper fouling when the rifle is cleaned. I use Butches Bore Shine followed with Sweets. I'm shooting the 75 gr V-Max with 31.5 Varget, just touching the lands. I'm certainly not knowledgeable on gunsmithing but have looked it over. Barrel is free floated to the action. Bedding looks rough,not neat, had to remove sawdust between the action and stock. Removed what appeared to be dirt inside the bolt assembly. Stripped screw holding on butt plate. Overall shoddy workmanship. Wish I bought a factory rifle. So now I have this expensive boat anchor that I would like to get to shoot. Taking any and all suggestions. I will clean after 10 rounds and see if this helps.

 

[jdavis62]

l had one like this about ten years back,it was a Rem.700 with
Hart barrel in 22-250 <Hart did not do the work> it would shoot
good for about 7 to 12 rounds then go to hell.l tried everything
no help,sold it,l told the man,he thought he was smarter than me
and could fix it,Ha,know what he did.he had his smith look it over.He said he barrel was to deep into the action and the threads were to loose,cut off the threads and rechambered it
last l knew it was shooting half inch groups...try having a
good gunsmith look at it...

 

[bbeyer]

Have you had the barrel off?
I was going to ask what the threads looked like.