nononsense /consistantly inconsistant

Milliron

We have a Weatherby Accumark in 300 WBY Mag. fitted with a leupold VX III 4.5-14 CDS. It is supposed to be sighted in 2" high at 100 yds. First shot will be on target. 2nd shot will be 3.5-4" low. third shot will be touching first shot. It is consistant in this pattern. I think first thing to do is change out scope and verify whether it is a rifle or a scope problem. What do you think? (My son's rifle. He wants more input than mine.)

Herschel

I seriously doubt if it is a scope problem. Probably something to do with the gun heating up after one shot. Try shooting one shot, allowing the gun to cool then another shot until you shoot the number you want for a group.

260

i would first try a different brand/type of ammunition. i am thinking barrel harmonics myself.

tsr1965

Milliron,

I might not be Nononsense, but it sounds a lot like something has induced stress.

First off, check to see if the barrel is free floating, or if there are some area's that are tight.

Providing the barrel is free floated, torque the front action screw to 60 inch pounds, then torque the back one to the same. Make sure the barrel is free floating still.

Next, how is the scope mounted? What bases and rings? If it is in the standard Leupold bases and rings, are the bases Loctited to the reciever, and the screws torqued to 30 inch pounds? Are the rings properly fitted, lapped, and ring caps torqued to no more than 15 inch pounds? Anything less, will induce torque to the scope. Also by all means, if they are the standard Leupold base and rings with the turn in front, always ue a wrench or properly sized wooden or polymer dowel to turn in the front ring. Never use the scopeto do this.

On a rifle like this, I would use a Picatinny style base, and a good tactical ring, like the Burris for starters, or Badger for better. If you were to use a Badger base and ring, you would not need to lap them.

Also a factor is the crown, which could do this, but the point of impacts would be totally inconsistant.

Have you tried various different loads, or are these results from just one load?

Lastly, have you tried a different driver? That might be the first thing to try, to make sure it is not the rifle/scope set up.

I am sure Nononsense will add more to this.

Best

EDIT 1

It is not heat that is doing this. It wouldn't do it from a 5 shot group with that barrel either. One of the keys to high end accuracy is rigidity, and stress free rifle/scope/stock systems...and good components. I stand by my statement, that stress is being introduced somewhere. The bedding block in the stock should be skim bedded for best results.

SP45

is it a light barrel. is it heating up between shots. is there pressure on it somewhere. some benefit from floating some not. check the stock screws make sure they are tightened correctly. check the scope mounts make sure they are correctly installed. make sure you are not putting pressure on the stock when sighting it in. check for shooter error. is the ammo factory or reloads. just a bunch of stuff that cuold go wrong. check the easy stuff first and if that doesn't help try changing out the scope and then the ammo. if nothing helps after that consider free floating the barrel or conversally adding a pressure point.

Milliron

The mounts are Talley rings and bases. Shots are consecutive. I can't believe that if heat were causing the second shot to fly wild that the third would go back to original point. Was shooting 180 grain hand loads. Not sure of the receipe. the rifle does not like them as well as the 168 grain handloads I referenced earlier. The rifle shot this way and was cleaned completely. Shot the same way after cleaning.

Milliron

again. it is consistant in first shot on target. 2nd shot low. third shot on target. it likes the 168 grain handloads best.

kumatelives

maybe off the wall but try wrapping the barrel in electrical tape about an inch in front of the forearm.this will stay any harmonics problems.first though check all the screws on the rifle including scope mount.sounds like a bedding problem with the aluminum insert and screw tension can alleviate the problem

bambambam

I don't think 2-3 shots will affect temperature that dramatic.IMHO

There is something wrong with the stock or scope or scope ring/base.

1. Make sure the barrel receiver isn't tightened with something in a bind in the stock. Shoot it.

2. Get different ammo to check. Shoot it.

3. Check everything that has to to with holding the scope. Shoot it.

4. Put another scope on the rifle to see if you are still getting impacts like this. Shoot it. Bad scope is probably the case here.

Also are you resting your hand on the scope when shooting?(I see some people do this, and some rifles don't like to be touched this way.[:I])

Edit:

I had this same problem with a slug gun this deer season. New scope and I was back in business.

Milliron

We are shooting the rifle on a bench with sand bags. I dont think it is a shooter issue or an ammunition issue. He is shooting 3 different rifles. This is the only one with an issue. He shoots a 270 WSM that will put all 3 shots touching at 100 yds Some new ideas to play with till we get it figured out. It certainly could be any one of many small things. Thanks to everyone for their time and thought.

woodhog

be sure and post,if/when you find a solution